Merge branch 'master' into BAEL-3760_Introduction_to_Takes

# Conflicts:
#	libraries-3/pom.xml

libraries-3/pom.xml

@@ -73,6 +73,16 @@
             <version>${cache2k.version}</version>
             <type>pom</type>
         </dependency>
+        <dependency>
+            <groupId>com.squareup.moshi</groupId>
+            <artifactId>moshi</artifactId>
+            <version>${moshi.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.squareup.moshi</groupId>
+            <artifactId>moshi-adapters</artifactId>
+            <version>${moshi.version}</version>
+        </dependency>
         <dependency>
             <groupId>com.jcabi</groupId>
             <artifactId>jcabi-aspects</artifactId>
@@ -191,7 +201,7 @@
         <cactoos.version>0.43</cactoos.version>
         <airline.version>2.7.2</airline.version>
         <cache2k.version>1.2.3.Final</cache2k.version>
-        
+        <moshi.version>1.9.2</moshi.version>
         <jcabi-aspects.version>0.22.6</jcabi-aspects.version>
         <aspectjrt.version>1.9.2</aspectjrt.version>
         <jcabi-maven-plugin.version>0.14.1</jcabi-maven-plugin.version>

libraries-3/src/test/java/com/baeldung/moshi/AlternativeAdapterUnitTest.java

@@ -0,0 +1,105 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.time.Instant;
+
+import com.squareup.moshi.FromJson;
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.JsonQualifier;
+import com.squareup.moshi.Moshi;
+import com.squareup.moshi.ToJson;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.junit.Test;
+
+public class AlternativeAdapterUnitTest {
+    @Test
+    public void whenSerializing_thenAlternativeAdapterUsed() {
+        Moshi moshi = new Moshi.Builder()
+          .add(new EpochMillisAdapter())
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        String json = jsonAdapter.toJson(new Post("Introduction to Moshi Json", "Baeldung", Instant.now()));
+        System.out.println(json);
+    }
+
+    @Test
+    public void whenDeserializing_thenAlternativeAdapterUsed() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .add(new EpochMillisAdapter())
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        String json = "{\"author\":\"Baeldung\",\"posted\":1582095269204,\"title\":\"Introduction to Moshi Json\"}";
+        Post post = jsonAdapter.fromJson(json);
+        System.out.println(post);
+
+    }
+
+    public static class Post {
+        String title;
+        String author;
+        @EpochMillis Instant posted;
+
+        public Post() {
+        }
+
+        public Post(String title, String author, Instant posted) {
+            this.title = title;
+            this.author = author;
+            this.posted = posted;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public void setTitle(String title) {
+            this.title = title;
+        }
+
+        public String getAuthor() {
+            return author;
+        }
+
+        public void setAuthor(String author) {
+            this.author = author;
+        }
+
+        public Instant getPosted() {
+            return posted;
+        }
+
+        public void setPosted(Instant posted) {
+            this.posted = posted;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this).append("title", title).append("author", author).append("posted", posted)
+                .toString();
+        }
+    }
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD})
+    @JsonQualifier
+    public @interface EpochMillis {
+    }
+
+    public static class EpochMillisAdapter {
+        @ToJson
+        public Long toJson(@EpochMillis Instant input) {
+            return input.toEpochMilli();
+        }
+        @FromJson
+        @EpochMillis
+        public Instant fromJson(Long input) {
+            return Instant.ofEpochMilli(input);
+        }
+
+    }
+}

libraries-3/src/test/java/com/baeldung/moshi/ArrayUnitTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.Arrays;
+import java.util.List;
+
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.Moshi;
+import com.squareup.moshi.Types;
+import org.junit.Test;
+
+public class ArrayUnitTest {
+    @Test
+    public void whenSerializingList_thenJsonArrayProduced() {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        Type type = Types.newParameterizedType(List.class, String.class);
+        JsonAdapter<List<String>> jsonAdapter = moshi.adapter(type);
+
+        String json = jsonAdapter.toJson(Arrays.asList("One", "Two", "Three"));
+        System.out.println(json);
+    }
+
+    @Test
+    public void whenDeserializingJsonArray_thenListProduced() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        Type type = Types.newParameterizedType(List.class, String.class);
+        JsonAdapter<List<String>> jsonAdapter = moshi.adapter(type);
+
+        String json = "[\"One\",\"Two\",\"Three\"]";
+        List<String> result = jsonAdapter.fromJson(json);
+        System.out.println(result);
+    }
+}

libraries-3/src/test/java/com/baeldung/moshi/ComplexAdapterUnitTest.java

@@ -0,0 +1,94 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+import com.squareup.moshi.FromJson;
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.Moshi;
+import com.squareup.moshi.ToJson;
+import org.junit.Test;
+
+public class ComplexAdapterUnitTest {
+    @Test
+    public void whenSerializing_thenCorrectJsonProduced() {
+        Moshi moshi = new Moshi.Builder()
+          .add(new JsonDateTimeAdapter())
+          .build();
+        JsonAdapter<ZonedDateTime> jsonAdapter = moshi.adapter(ZonedDateTime.class);
+
+        String json = jsonAdapter.toJson(ZonedDateTime.now());
+        System.out.println(json);
+    }
+
+    @Test
+    public void whenDeserializing_thenCorrectJsonConsumed() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .add(new JsonDateTimeAdapter())
+          .build();
+        JsonAdapter<ZonedDateTime> jsonAdapter = moshi.adapter(ZonedDateTime.class);
+
+        String json = "{\"date\":\"2020-02-17\",\"time\":\"07:53:27.064\",\"timezone\":\"Europe/London\"}";
+        ZonedDateTime now = jsonAdapter.fromJson(json);
+        System.out.println(now);
+
+    }
+
+    public static class JsonDateTimeAdapter {
+        @ToJson
+        public JsonDateTime toJson(ZonedDateTime input) {
+            String date = input.toLocalDate().toString();
+            String time = input.toLocalTime().toString();
+            String timezone = input.getZone().toString();
+            return new JsonDateTime(date, time, timezone);
+        }
+        @FromJson
+        public ZonedDateTime fromJson(JsonDateTime input) {
+            LocalDate date = LocalDate.parse(input.getDate());
+            LocalTime time = LocalTime.parse(input.getTime());
+            ZoneId timezone = ZoneId.of(input.getTimezone());
+            return ZonedDateTime.of(date, time, timezone);
+        }
+    }
+    public static class JsonDateTime {
+        private String date;
+        private String time;
+        private String timezone;
+
+        public JsonDateTime() {
+        }
+
+        public JsonDateTime(String date, String time, String timezone) {
+            this.date = date;
+            this.time = time;
+            this.timezone = timezone;
+        }
+
+        public String getDate() {
+            return date;
+        }
+
+        public void setDate(String date) {
+            this.date = date;
+        }
+
+        public String getTime() {
+            return time;
+        }
+
+        public void setTime(String time) {
+            this.time = time;
+        }
+
+        public String getTimezone() {
+            return timezone;
+        }
+
+        public void setTimezone(String timezone) {
+            this.timezone = timezone;
+        }
+    }
+}

libraries-3/src/test/java/com/baeldung/moshi/DefaultUnitTest.java

@@ -0,0 +1,68 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+import java.time.Instant;
+
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.Moshi;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.junit.Test;
+
+public class DefaultUnitTest {
+
+    @Test
+    public void whenDeserializing_thenFieldsGetDefaultValues() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        String json = "{\"title\":\"My Post\"}";
+        Post post = jsonAdapter.fromJson(json);
+        System.out.println(post);
+    }
+    public static class Post {
+        private String title;
+        private String author;
+        private String posted;
+
+        public Post() {
+            posted = Instant.now().toString();
+        }
+
+        public Post(String title, String author, String posted) {
+            this.title = title;
+            this.author = author;
+            this.posted = posted;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public void setTitle(String title) {
+            this.title = title;
+        }
+
+        public String getAuthor() {
+            return author;
+        }
+
+        public void setAuthor(String author) {
+            this.author = author;
+        }
+
+        public String getPosted() {
+            return posted;
+        }
+
+        public void setPosted(String posted) {
+            this.posted = posted;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this).append("title", title).append("author", author).append("posted", posted)
+                .toString();
+        }
+    }
+}

libraries-3/src/test/java/com/baeldung/moshi/PrimitiveUnitTest.java

@@ -0,0 +1,77 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.Moshi;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.junit.Test;
+
+public class PrimitiveUnitTest {
+    @Test
+    public void whenSerializing_thenCorrectJsonProduced() {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        Post post = new Post("My Post", "Baeldung", "This is my post");
+        String json = jsonAdapter.toJson(post);
+        System.out.println(json);
+    }
+
+    @Test
+    public void whenDeserializing_thenCorrectJsonConsumed() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        String json = "{\"author\":\"Baeldung\",\"text\":\"This is my post\",\"title\":\"My Post\"}";
+        Post post = jsonAdapter.fromJson(json);
+        System.out.println(post);
+    }
+
+    public static class Post {
+        private String title;
+        private String author;
+        private String text;
+
+        public Post() {
+        }
+
+        public Post(String title, String author, String text) {
+            this.title = title;
+            this.author = author;
+            this.text = text;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public void setTitle(String title) {
+            this.title = title;
+        }
+
+        public String getAuthor() {
+            return author;
+        }
+
+        public void setAuthor(String author) {
+            this.author = author;
+        }
+
+        public String getText() {
+            return text;
+        }
+
+        public void setText(String text) {
+            this.text = text;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this).append("title", title).append("author", author).append("text", text)
+                .toString();
+        }
+    }
+}

libraries-3/src/test/java/com/baeldung/moshi/RenameUnitTest.java

@@ -0,0 +1,68 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+
+import com.squareup.moshi.Json;
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.Moshi;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.junit.jupiter.api.Test;
+
+public class RenameUnitTest {
+
+    @Test
+    public void whenSerializing_thenFieldsGetRenamed() {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        Post post = new Post("My Post", "Baeldung");
+        String json = jsonAdapter.toJson(post);
+        System.out.println(json);
+    }
+
+    @Test
+    public void whenSerializing_thenRenamedFieldsGetConsumed() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        String json = "{\"authored_by\":\"Baeldung\",\"title\":\"My Post\"}";
+        Post post = jsonAdapter.fromJson(json);
+        System.out.println(post);
+    }
+    public static class Post {
+        private String title;
+        @Json(name = "authored_by")
+        private String author;
+
+        public Post() {
+        }
+
+        public Post(String title, String author) {
+            this.title = title;
+            this.author = author;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public void setTitle(String title) {
+            this.title = title;
+        }
+
+        public String getAuthor() {
+            return author;
+        }
+
+        public void setAuthor(String author) {
+            this.author = author;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this).append("title", title).append("author", author).toString();
+        }
+    }
+}

libraries-3/src/test/java/com/baeldung/moshi/SimpleAdapterUnitTest.java

@@ -0,0 +1,129 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import com.squareup.moshi.FromJson;
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.Moshi;
+import com.squareup.moshi.ToJson;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.junit.Test;
+
+public class SimpleAdapterUnitTest {
+    @Test
+    public void whenSerializing_thenAdapterUsed() {
+        Moshi moshi = new Moshi.Builder()
+          .add(new AuthorAdapter())
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        Post post = new Post("My Post", new Author("Baeldung", "[email protected]"), "This is my post");
+        String json = jsonAdapter.toJson(post);
+        System.out.println(json);
+    }
+
+    @Test
+    public void whenDeserializing_thenAdapterUsed() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .add(new AuthorAdapter())
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        String json = "{\"author\":\"Baeldung <[email protected]>\",\"text\":\"This is my post\",\"title\":\"My Post\"}";
+        Post post = jsonAdapter.fromJson(json);
+        System.out.println(post);
+    }
+    public static class AuthorAdapter {
+        private Pattern pattern = Pattern.compile("^(.*) <(.*)>$");
+        @ToJson
+        public String toJson(Author author) {
+            return author.name + " <" + author.email + ">";
+        }
+
+        @FromJson
+        public Author fromJson(String author) {
+            Matcher matcher = pattern.matcher(author);
+            return matcher.find() ? new Author(matcher.group(1), matcher.group(2)) : null;
+        }
+    }
+
+    public static class Author {
+        private String name;
+        private String email;
+
+        public Author() {
+        }
+
+        public Author(String name, String email) {
+            this.name = name;
+            this.email = email;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+        public String getEmail() {
+            return email;
+        }
+
+        public void setEmail(String email) {
+            this.email = email;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this).append("name", name).append("email", email).toString();
+        }
+    }
+    public static class Post {
+        private String title;
+        private Author author;
+        private String text;
+
+        public Post() {
+        }
+
+        public Post(String title, Author author, String text) {
+            this.title = title;
+            this.author = author;
+            this.text = text;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public void setTitle(String title) {
+            this.title = title;
+        }
+
+        public Author getAuthor() {
+            return author;
+        }
+
+        public void setAuthor(Author author) {
+            this.author = author;
+        }
+
+        public String getText() {
+            return text;
+        }
+
+        public void setText(String text) {
+            this.text = text;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this).append("title", title).append("author", author).append("text", text)
+              .toString();
+        }
+    }
+}

libraries-3/src/test/java/com/baeldung/moshi/TransientUnitTest.java

@@ -0,0 +1,66 @@
+package com.baeldung.moshi;
+
+import java.io.IOException;
+
+import com.squareup.moshi.JsonAdapter;
+import com.squareup.moshi.Moshi;
+import org.apache.commons.lang3.builder.ToStringBuilder;
+import org.junit.jupiter.api.Test;
+
+public class TransientUnitTest {
+
+    @Test
+    public void whenSerializing_thenTransientFieldIgnored() {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        Post post = new Post("My Post", "Baeldung");
+        String json = jsonAdapter.toJson(post);
+        System.out.println(json);
+    }
+
+    @Test
+    public void whenDeserializing_thenTransientFieldIgnored() throws IOException {
+        Moshi moshi = new Moshi.Builder()
+          .build();
+        JsonAdapter<Post> jsonAdapter = moshi.adapter(Post.class);
+
+        String json = "{\"authored_by\":\"Baeldung\",\"title\":\"My Post\"}";
+        Post post = jsonAdapter.fromJson(json);
+        System.out.println(post);
+    }
+    public static class Post {
+        private String title;
+        private transient String author;
+
+        public Post() {
+        }
+
+        public Post(String title, String author) {
+            this.title = title;
+            this.author = author;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public void setTitle(String title) {
+            this.title = title;
+        }
+
+        public String getAuthor() {
+            return author;
+        }
+
+        public void setAuthor(String author) {
+            this.author = author;
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this).append("title", title).append("author", author).toString();
+        }
+    }
+}

spring-batch/src/main/java/org/baeldung/batch/App.java

@@ -18,6 +18,8 @@ public class App {
         final AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
         context.register(SpringConfig.class);
         context.register(SpringBatchConfig.class);
+        context.register(SpringBatchRetryConfig.class);
+
         context.refresh();
 
         // Spring xml config
@@ -26,6 +28,8 @@ public class App {
         runJob(context, "firstBatchJob");
         runJob(context, "skippingBatchJob");
         runJob(context, "skipPolicyBatchJob");
+        runJob(context, "retryBatchJob");
+
     }
 
     private static void runJob(AnnotationConfigApplicationContext context, String batchJobName) {

spring-batch/src/main/java/org/baeldung/batch/SpringBatchRetryConfig.java

@@ -0,0 +1,117 @@
+package org.baeldung.batch;
+
+import org.apache.http.client.config.RequestConfig;
+import org.apache.http.conn.ConnectTimeoutException;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.baeldung.batch.model.Transaction;
+import org.baeldung.batch.service.RecordFieldSetMapper;
+import org.baeldung.batch.service.RetryItemProcessor;
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.Step;
+import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
+import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
+import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
+import org.springframework.batch.item.ItemProcessor;
+import org.springframework.batch.item.ItemReader;
+import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.item.file.FlatFileItemReader;
+import org.springframework.batch.item.file.mapping.DefaultLineMapper;
+import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
+import org.springframework.batch.item.xml.StaxEventItemWriter;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.io.Resource;
+import org.springframework.dao.DeadlockLoserDataAccessException;
+import org.springframework.oxm.Marshaller;
+import org.springframework.oxm.jaxb.Jaxb2Marshaller;
+
+import java.text.ParseException;
+
+@Configuration
+@EnableBatchProcessing
+public class SpringBatchRetryConfig {
+    
+    private static final String[] tokens = { "username", "userid", "transactiondate", "amount" };
+    private static final int TWO_SECONDS = 2000;
+
+    @Autowired
+    private JobBuilderFactory jobBuilderFactory;
+
+    @Autowired
+    private StepBuilderFactory stepBuilderFactory;
+
+    @Value("input/recordRetry.csv")
+    private Resource inputCsv;
+
+    @Value("file:xml/retryOutput.xml")
+    private Resource outputXml;
+
+    public ItemReader<Transaction> itemReader(Resource inputData) throws ParseException {
+        DelimitedLineTokenizer tokenizer = new DelimitedLineTokenizer();
+        tokenizer.setNames(tokens);
+        DefaultLineMapper<Transaction> lineMapper = new DefaultLineMapper<>();
+        lineMapper.setLineTokenizer(tokenizer);
+        lineMapper.setFieldSetMapper(new RecordFieldSetMapper());
+        FlatFileItemReader<Transaction> reader = new FlatFileItemReader<>();
+        reader.setResource(inputData);
+        reader.setLinesToSkip(1);
+        reader.setLineMapper(lineMapper);
+        return reader;
+    }
+
+    @Bean
+    public CloseableHttpClient closeableHttpClient() {
+        final RequestConfig config = RequestConfig.custom()
+          .setConnectTimeout(TWO_SECONDS)
+          .build();
+        return HttpClientBuilder.create().setDefaultRequestConfig(config).build();
+    }
+
+    @Bean
+    public ItemProcessor<Transaction, Transaction> retryItemProcessor() {
+        return new RetryItemProcessor();
+    }
+
+    @Bean
+    public ItemWriter<Transaction> itemWriter(Marshaller marshaller) {
+        StaxEventItemWriter<Transaction> itemWriter = new StaxEventItemWriter<>();
+        itemWriter.setMarshaller(marshaller);
+        itemWriter.setRootTagName("transactionRecord");
+        itemWriter.setResource(outputXml);
+        return itemWriter;
+    }
+
+    @Bean
+    public Marshaller marshaller() {
+        Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
+        marshaller.setClassesToBeBound(Transaction.class);
+        return marshaller;
+    }
+
+    @Bean
+    public Step retryStep(@Qualifier("retryItemProcessor") ItemProcessor<Transaction, Transaction> processor,
+      ItemWriter<Transaction> writer) throws ParseException {
+        return stepBuilderFactory.get("retryStep")
+          .<Transaction, Transaction>chunk(10)
+          .reader(itemReader(inputCsv))
+          .processor(processor)
+          .writer(writer)
+          .faultTolerant()
+          .retryLimit(3)
+          .retry(ConnectTimeoutException.class)
+          .retry(DeadlockLoserDataAccessException.class)
+          .build();
+    }
+
+    @Bean(name = "retryBatchJob")
+    public Job retryJob(@Qualifier("retryStep") Step retryStep) {
+        return jobBuilderFactory
+          .get("retryBatchJob")
+          .start(retryStep)
+          .build();
+    }
+}

spring-batch/src/main/java/org/baeldung/batch/model/Transaction.java

@@ -9,6 +9,8 @@ import javax.xml.bind.annotation.XmlRootElement;
 public class Transaction {
     private String username;
     private int userId;
+    private int age;
+    private String postCode;
     private Date transactionDate;
     private double amount;
 
@@ -46,9 +48,25 @@ public class Transaction {
         this.amount = amount;
     }
 
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public String getPostCode() {
+        return postCode;
+    }
+
+    public void setPostCode(String postCode) {
+        this.postCode = postCode;
+    }
+
     @Override
     public String toString() {
-        return "Transaction [username=" + username + ", userId=" + userId + ", transactionDate=" + transactionDate + ", amount=" + amount + "]";
+        return "Transaction [username=" + username + ", userId=" + userId + ", age=" + age + ", postCode=" + postCode + ", transactionDate=" + transactionDate + ", amount=" + amount + "]";
     }
 
 }

spring-batch/src/main/java/org/baeldung/batch/service/RetryItemProcessor.java

@@ -0,0 +1,42 @@
+package org.baeldung.batch.service;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.util.EntityUtils;
+import org.baeldung.batch.model.Transaction;
+import org.codehaus.jettison.json.JSONException;
+import org.codehaus.jettison.json.JSONObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.batch.item.ItemProcessor;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.io.IOException;
+
+public class RetryItemProcessor implements ItemProcessor<Transaction, Transaction> {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(RetryItemProcessor.class);
+
+    @Autowired
+    private CloseableHttpClient closeableHttpClient;
+
+    @Override
+    public Transaction process(Transaction transaction) throws IOException, JSONException {
+        LOGGER.info("Attempting to process user with id={}", transaction.getUserId());
+        HttpResponse response = fetchMoreUserDetails(transaction.getUserId());
+
+        //parse user's age and postCode from response and update transaction
+        String result = EntityUtils.toString(response.getEntity());
+        JSONObject userObject = new JSONObject(result);
+        transaction.setAge(Integer.parseInt(userObject.getString("age")));
+        transaction.setPostCode(userObject.getString("postCode"));
+
+        return transaction;
+    }
+
+    private HttpResponse fetchMoreUserDetails(int id) throws IOException {
+        final HttpGet request = new HttpGet("http://www.baeldung.com:81/user/" + id);
+        return closeableHttpClient.execute(request);
+    }
+}

spring-batch/src/main/resources/input/recordRetry.csv

@@ -0,0 +1,3 @@
+username, user_id, transaction_date, transaction_amount
+sammy, 1234, 31/10/2015, 10000
+john, 9999, 3/12/2015, 12321

spring-batch/src/main/resources/spring-batch-intro.xml

@@ -54,4 +54,19 @@
             </batch:tasklet>
         </batch:step>
     </batch:job>
+
+    <batch:job id="retryBatchJob">
+        <batch:step id="retryStep">
+            <batch:tasklet>
+                <batch:chunk reader="itemReader" writer="itemWriter"
+                             processor="retryItemProcessor" commit-interval="10"
+                             retry-limit="3">
+                    <batch:retryable-exception-classes>
+                        <batch:include class="org.apache.http.conn.ConnectTimeoutException"/>
+                        <batch:include class="org.springframework.dao.DeadlockLoserDataAccessException"/>
+                    </batch:retryable-exception-classes>
+                </batch:chunk>
+            </batch:tasklet>
+        </batch:step>
+    </batch:job>
 </beans>

spring-batch/src/test/java/org/baeldung/batch/SpringBatchRetryIntegrationTest.java

@@ -0,0 +1,90 @@
+package org.baeldung.batch;
+
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.conn.ConnectTimeoutException;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.springframework.batch.core.ExitStatus;
+import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobInstance;
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersBuilder;
+import org.springframework.batch.test.AssertFile;
+import org.springframework.batch.test.JobLauncherTestUtils;
+import org.springframework.batch.test.context.SpringBatchTest;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+@RunWith(SpringRunner.class)
+@SpringBatchTest
+@EnableAutoConfiguration
+@ContextConfiguration(classes = { SpringBatchRetryConfig.class })
+public class SpringBatchRetryIntegrationTest {
+
+    private static final String TEST_OUTPUT = "xml/retryOutput.xml";
+    private static final String EXPECTED_OUTPUT = "src/test/resources/output/batchRetry/retryOutput.xml";
+
+    @Autowired
+    private JobLauncherTestUtils jobLauncherTestUtils;
+
+    @MockBean
+    private CloseableHttpClient closeableHttpClient;
+
+    @Mock
+    private CloseableHttpResponse httpResponse;
+
+    @Test
+    public void whenEndpointAlwaysFail_thenJobFails() throws Exception {
+        when(closeableHttpClient.execute(any()))
+          .thenThrow(new ConnectTimeoutException("Endpoint is down"));
+
+        JobExecution jobExecution = jobLauncherTestUtils.launchJob(defaultJobParameters());
+        JobInstance actualJobInstance = jobExecution.getJobInstance();
+        ExitStatus actualJobExitStatus = jobExecution.getExitStatus();
+
+        assertThat(actualJobInstance.getJobName(), is("retryBatchJob"));
+        assertThat(actualJobExitStatus.getExitCode(), is("FAILED"));
+        assertThat(actualJobExitStatus.getExitDescription(), containsString("org.apache.http.conn.ConnectTimeoutException"));
+    }
+
+    @Test
+    public void whenEndpointFailsTwicePasses3rdTime_thenSuccess() throws Exception {
+        FileSystemResource expectedResult = new FileSystemResource(EXPECTED_OUTPUT);
+        FileSystemResource actualResult = new FileSystemResource(TEST_OUTPUT);
+
+        //fails for first two calls and passes third time onwards
+        when(httpResponse.getEntity())
+          .thenReturn(new StringEntity("{ \"age\":10, \"postCode\":\"430222\" }"));
+        when(closeableHttpClient.execute(any()))
+          .thenThrow(new ConnectTimeoutException("Timeout count 1"))
+          .thenThrow(new ConnectTimeoutException("Timeout count 2"))
+          .thenReturn(httpResponse);
+
+        JobExecution jobExecution = jobLauncherTestUtils.launchJob(defaultJobParameters());
+        JobInstance actualJobInstance = jobExecution.getJobInstance();
+        ExitStatus actualJobExitStatus = jobExecution.getExitStatus();
+
+        assertThat(actualJobInstance.getJobName(), is("retryBatchJob"));
+        assertThat(actualJobExitStatus.getExitCode(), is("COMPLETED"));
+        AssertFile.assertFileEquals(expectedResult, actualResult);
+    }
+    
+    private JobParameters defaultJobParameters() {
+        JobParametersBuilder paramsBuilder = new JobParametersBuilder();
+        paramsBuilder.addString("jobID", String.valueOf(System.currentTimeMillis()));
+        return paramsBuilder.toJobParameters();
+    }
+}

spring-batch/src/test/resources/output/batchRetry/retryOutput.xml

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8"?><transactionRecord><transactionRecord><age>10</age><amount>10000.0</amount><postCode>430222</postCode><transactionDate>2015-10-31T00:00:00+05:30</transactionDate><userId>1234</userId><username>sammy</username></transactionRecord><transactionRecord><age>10</age><amount>12321.0</amount><postCode>430222</postCode><transactionDate>2015-12-03T00:00:00+05:30</transactionDate><userId>9999</userId><username>john</username></transactionRecord></transactionRecord>

spring-batch/xml/retryOutput.xml

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8"?><transactionRecord><transactionRecord><age>10</age><amount>10000.0</amount><postCode>430222</postCode><transactionDate>2015-10-31T00:00:00+05:30</transactionDate><userId>1234</userId><username>sammy</username></transactionRecord><transactionRecord><age>10</age><amount>12321.0</amount><postCode>430222</postCode><transactionDate>2015-12-03T00:00:00+05:30</transactionDate><userId>9999</userId><username>john</username></transactionRecord></transactionRecord>

spring-rest-http/pom.xml

@@ -41,12 +41,18 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.github.java-json-tools</groupId>
+            <artifactId>json-patch</artifactId>
+            <version>${jsonpatch.version}</version>
+        </dependency>
 
     </dependencies>
 
 
     <properties>
         <xstream.version>1.4.9</xstream.version>
+        <jsonpatch.version>1.12</jsonpatch.version>
     </properties>
 
 </project>

spring-rest-http/src/main/java/com/baeldung/CustomerSpringBootRestApplication.java

@@ -0,0 +1,12 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class CustomerSpringBootRestApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(CustomerSpringBootRestApplication.class, args);
+    }
+}

spring-rest-http/src/main/java/com/baeldung/model/Customer.java

@@ -0,0 +1,79 @@
+package com.baeldung.model;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+public class Customer {
+    private String id;
+    private String telephone;
+    private List<String> favorites;
+    private Map<String, Boolean> communicationPreferences;
+
+    public Customer() {
+    }
+
+    public Customer(String id, String telephone, List<String> favorites, Map<String, Boolean> communicationPreferences) {
+        this(telephone, favorites, communicationPreferences);
+        this.id = id;
+    }
+
+    public Customer(String telephone, List<String> favorites, Map<String, Boolean> communicationPreferences) {
+        this.telephone = telephone;
+        this.favorites = favorites;
+        this.communicationPreferences = communicationPreferences;
+    }
+
+    public static Customer fromCustomer(Customer customer) {
+        return new Customer(customer.getId(), customer.getTelephone(), customer.getFavorites(), customer.getCommunicationPreferences());
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getTelephone() {
+        return telephone;
+    }
+
+    public void setTelephone(String telephone) {
+        this.telephone = telephone;
+    }
+
+    public Map<String, Boolean> getCommunicationPreferences() {
+        return communicationPreferences;
+    }
+
+    public void setCommunicationPreferences(Map<String, Boolean> communicationPreferences) {
+        this.communicationPreferences = communicationPreferences;
+    }
+
+    public List<String> getFavorites() {
+        return favorites;
+    }
+
+    public void setFavorites(List<String> favorites) {
+        this.favorites = favorites;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof Customer)) {
+            return false;
+        }
+        Customer customer = (Customer) o;
+        return Objects.equals(id, customer.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+}

spring-rest-http/src/main/java/com/baeldung/service/CustomerIdGenerator.java

@@ -0,0 +1,6 @@
+package com.baeldung.service;
+
+public interface CustomerIdGenerator {
+    int generateNextId();
+}
+

spring-rest-http/src/main/java/com/baeldung/service/CustomerService.java

@@ -0,0 +1,14 @@
+package com.baeldung.service;
+
+import com.baeldung.model.Customer;
+
+import java.util.Optional;
+
+public interface CustomerService {
+
+    Customer createCustomer(Customer customer);
+
+    Optional<Customer> findCustomer(String id);
+
+    void updateCustomer(Customer customer);
+}

spring-rest-http/src/main/java/com/baeldung/service/impl/CustomerIdGeneratorImpl.java

@@ -0,0 +1,17 @@
+package com.baeldung.service.impl;
+
+import com.baeldung.service.CustomerIdGenerator;
+
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+@Component
+public class CustomerIdGeneratorImpl implements CustomerIdGenerator {
+    private static final AtomicInteger SEQUENCE = new AtomicInteger();
+
+    @Override
+    public int generateNextId() {
+        return SEQUENCE.incrementAndGet();
+    }
+}

spring-rest-http/src/main/java/com/baeldung/service/impl/CustomerServiceImpl.java

@@ -0,0 +1,42 @@
+package com.baeldung.service.impl;
+
+import com.baeldung.model.Customer;
+import com.baeldung.service.CustomerIdGenerator;
+import com.baeldung.service.CustomerService;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+@Service
+public class CustomerServiceImpl implements CustomerService {
+    private CustomerIdGenerator customerIdGenerator;
+    private List<Customer> customers = new ArrayList<>();
+
+    @Autowired
+    public CustomerServiceImpl(CustomerIdGenerator customerIdGenerator) {
+        this.customerIdGenerator = customerIdGenerator;
+    }
+
+    @Override
+    public Customer createCustomer(Customer customer) {
+        customer.setId(Integer.toString(customerIdGenerator.generateNextId()));
+        customers.add(customer);
+        return customer;
+    }
+
+    @Override
+    public Optional<Customer> findCustomer(String id) {
+        return customers.stream()
+                        .filter(customer -> customer.getId().equals(id))
+                        .findFirst();
+    }
+
+    @Override
+    public void updateCustomer(Customer customer) {
+        customers.set(customers.indexOf(customer), customer);
+    }
+}

spring-rest-http/src/main/java/com/baeldung/web/controller/CustomerRestController.java

@@ -0,0 +1,69 @@
+package com.baeldung.web.controller;
+
+import com.baeldung.model.Customer;
+import com.baeldung.service.CustomerService;
+import com.baeldung.web.exception.CustomerNotFoundException;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.github.fge.jsonpatch.JsonPatch;
+import com.github.fge.jsonpatch.JsonPatchException;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PatchMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
+
+import java.net.URI;
+
+import javax.validation.Valid;
+
+@RestController
+@RequestMapping(value = "/customers")
+public class CustomerRestController {
+    private CustomerService customerService;
+    private ObjectMapper objectMapper = new ObjectMapper();
+
+    @Autowired
+    public CustomerRestController(CustomerService customerService) {
+        this.customerService = customerService;
+    }
+
+    @PostMapping(consumes = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<Customer> createCustomer(@RequestBody Customer customer) {
+        Customer customerCreated = customerService.createCustomer(customer);
+        URI location = ServletUriComponentsBuilder.fromCurrentRequest()
+                                                  .path("/{id}")
+                                                  .buildAndExpand(customerCreated.getId())
+                                                  .toUri();
+        return ResponseEntity.created(location).build();
+    }
+
+    @PatchMapping(path = "/{id}", consumes = "application/json-patch+json")
+    public ResponseEntity<Customer> updateCustomer(@PathVariable String id,
+                                                   @RequestBody JsonPatch patch) {
+        try {
+            Customer customer = customerService.findCustomer(id).orElseThrow(CustomerNotFoundException::new);
+            Customer customerPatched = applyPatchToCustomer(patch, customer);
+            customerService.updateCustomer(customerPatched);
+
+            return ResponseEntity.ok(customerPatched);
+        } catch (CustomerNotFoundException e) {
+            return ResponseEntity.status(HttpStatus.NOT_FOUND).build();
+        } catch (JsonPatchException | JsonProcessingException e) {
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).build();
+        }
+    }
+
+    private Customer applyPatchToCustomer(JsonPatch patch, Customer targetCustomer) throws JsonPatchException, JsonProcessingException {
+        JsonNode patched = patch.apply(objectMapper.convertValue(targetCustomer, JsonNode.class));
+        return objectMapper.treeToValue(patched, Customer.class);
+    }
+}

spring-rest-http/src/main/java/com/baeldung/web/exception/CustomerNotFoundException.java

@@ -0,0 +1,5 @@
+package com.baeldung.web.exception;
+
+public class CustomerNotFoundException extends RuntimeException {
+
+}

spring-rest-http/src/test/java/com/baeldung/service/impl/CustomerIdGeneratorImplUnitTest.java

@@ -0,0 +1,17 @@
+package com.baeldung.service.impl;
+
+import com.baeldung.service.CustomerIdGenerator;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class CustomerIdGeneratorImplUnitTest {
+
+    @Test
+    public void givenIdGeneratedPreviously_whenGenerated_thenIdIsIncremented(){
+        CustomerIdGenerator customerIdGenerator = new CustomerIdGeneratorImpl();
+        int firstId = customerIdGenerator.generateNextId();
+        assertThat(customerIdGenerator.generateNextId()).isEqualTo(++firstId);
+    }
+}

spring-rest-http/src/test/java/com/baeldung/service/impl/CustomerServiceImplUnitTest.java

@@ -0,0 +1,94 @@
+package com.baeldung.service.impl;
+
+
+import com.baeldung.model.Customer;
+import com.baeldung.service.CustomerIdGenerator;
+import com.baeldung.service.CustomerService;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.util.HashMap;
+import java.util.Map;
+
+
+import static com.baeldung.model.Customer.fromCustomer;
+import static java.util.Arrays.asList;
+import static java.util.Optional.empty;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+
+@RunWith(MockitoJUnitRunner.class)
+public class CustomerServiceImplUnitTest {
+
+    @Mock
+    private CustomerIdGenerator mockCustomerIdGenerator;
+
+    private CustomerService customerService;
+
+    @Before
+    public void setup() {
+        customerService = new CustomerServiceImpl(mockCustomerIdGenerator);
+    }
+
+    @Test
+    public void whenCustomerIsCreated_thenNewCustomerDetailsAreCorrect() {
+        Map<String, Boolean> communicationPreferences = new HashMap<>();
+        communicationPreferences.put("post", true);
+        communicationPreferences.put("email", true);
+        Customer customer = new Customer("001-555-1234", asList("Milk", "Eggs"), communicationPreferences);
+        given(mockCustomerIdGenerator.generateNextId()).willReturn(1);
+
+        Customer newCustomer = customerService.createCustomer(customer);
+
+        assertThat(newCustomer.getId()).isEqualTo("1");
+        assertThat(newCustomer.getTelephone()).isEqualTo("001-555-1234");
+        assertThat(newCustomer.getFavorites()).containsExactly("Milk", "Eggs");
+        assertThat(newCustomer.getCommunicationPreferences()).isEqualTo(communicationPreferences);
+    }
+
+    @Test
+    public void givenNonExistentCustomer_whenCustomerIsLookedUp_thenCustomerCanNotBeFound() {
+        assertThat(customerService.findCustomer("CUST12345")).isEqualTo(empty());
+    }
+
+    @Test
+    public void whenCustomerIsCreated_thenCustomerCanBeFound() {
+        Map<String, Boolean> communicationPreferences = new HashMap<>();
+        communicationPreferences.put("post", true);
+        communicationPreferences.put("email", true);
+        Customer customer = new Customer("001-555-1234", asList("Milk", "Eggs"), communicationPreferences);
+        given(mockCustomerIdGenerator.generateNextId()).willReturn(7890);
+
+        customerService.createCustomer(customer);
+        Customer lookedUpCustomer = customerService.findCustomer("7890").get();
+
+        assertThat(lookedUpCustomer.getId()).isEqualTo("7890");
+        assertThat(lookedUpCustomer.getTelephone()).isEqualTo("001-555-1234");
+        assertThat(lookedUpCustomer.getFavorites()).containsExactly("Milk", "Eggs");
+        assertThat(lookedUpCustomer.getCommunicationPreferences()).isEqualTo(communicationPreferences);
+    }
+
+    @Test
+    public void whenCustomerUpdated_thenDetailsUpdatedCorrectly() {
+        given(mockCustomerIdGenerator.generateNextId()).willReturn(7890);
+        Map<String, Boolean> communicationPreferences = new HashMap<>();
+        communicationPreferences.put("post", true);
+        communicationPreferences.put("email", true);
+        Customer customer = new Customer("001-555-1234", asList("Milk", "Eggs"), communicationPreferences);
+        Customer newCustomer = customerService.createCustomer(customer);
+
+        Customer customerWithUpdates = fromCustomer(newCustomer);
+        customerWithUpdates.setTelephone("001-555-6789");
+        customerService.updateCustomer(customerWithUpdates);
+        Customer lookedUpCustomer = customerService.findCustomer("7890").get();
+
+        assertThat(lookedUpCustomer.getId()).isEqualTo("7890");
+        assertThat(lookedUpCustomer.getTelephone()).isEqualTo("001-555-6789");
+        assertThat(lookedUpCustomer.getFavorites()).containsExactly("Milk", "Eggs");
+        assertThat(lookedUpCustomer.getCommunicationPreferences()).isEqualTo(communicationPreferences);
+    }
+}

spring-rest-http/src/test/java/com/baeldung/web/controller/CustomerRestControllerIntegrationTest.java

@@ -0,0 +1,72 @@
+package com.baeldung.web.controller;
+
+import com.baeldung.model.Customer;
+import com.baeldung.service.CustomerService;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.util.Collections.emptyList;
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class CustomerRestControllerIntegrationTest {
+
+    @Autowired
+    private CustomerService customerService;
+
+    @Autowired
+    private TestRestTemplate testRestTemplate;
+
+    @Before
+    public void setup() {
+        testRestTemplate.getRestTemplate().setRequestFactory(new HttpComponentsClientHttpRequestFactory());
+    }
+
+    @Test
+    public void givenExistingCustomer_whenPatched_thenOnlyPatchedFieldsUpdated() {
+        Map<String, Boolean> communicationPreferences = new HashMap<>();
+        communicationPreferences.put("post", true);
+        communicationPreferences.put("email", true);
+        Customer newCustomer = new Customer("001-555-1234", Arrays.asList("Milk", "Eggs"),
+                                          communicationPreferences);
+        Customer customer = customerService.createCustomer(newCustomer);
+
+
+        String patchBody = "[ { \"op\": \"replace\", \"path\": \"/telephone\", \"value\": \"001-555-5678\" },\n"
+                           + "{\"op\": \"add\", \"path\": \"/favorites/0\", \"value\": \"Bread\" }]";
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.valueOf("application/json-patch+json"));
+        ResponseEntity<Customer> patchResponse
+                = testRestTemplate.exchange("/customers/{id}",
+                                            HttpMethod.PATCH,
+                                            new HttpEntity<>(patchBody, headers),
+                                            Customer.class,
+                                            customer.getId());
+
+        Customer customerPatched = patchResponse.getBody();
+        assertThat(patchResponse.getStatusCode()).isEqualTo(HttpStatus.OK);
+        assertThat(customerPatched.getId()).isEqualTo(customer.getId());
+        assertThat(customerPatched.getTelephone()).isEqualTo("001-555-5678");
+        assertThat(customerPatched.getCommunicationPreferences().get("post")).isTrue();
+        assertThat(customerPatched.getCommunicationPreferences().get("email")).isTrue();
+        assertThat(customerPatched.getFavorites()).containsExactly("Bread", "Milk", "Eggs");
+    }
+}