diff --git a/libraries-io/pom.xml b/libraries-io/pom.xml index e92f6e11e1..fa89ebeabe 100644 --- a/libraries-io/pom.xml +++ b/libraries-io/pom.xml @@ -5,6 +5,18 @@ 4.0.0 libraries-io libraries-io + + + + org.apache.maven.plugins + maven-compiler-plugin + + 17 + 17 + + + + com.baeldung @@ -34,6 +46,11 @@ zip4j ${zip4j.version} + + com.opencsv + opencsv + ${opencsv.version} + @@ -42,6 +59,10 @@ 0.27.0 2.4 2.9.0 + 5.7.1 + 17 + 17 + UTF-8 \ No newline at end of file diff --git a/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/Application.java b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/Application.java new file mode 100644 index 0000000000..b84da6229b --- /dev/null +++ b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/Application.java @@ -0,0 +1,4 @@ +package com.baeldung.java.io.pojotocsv; + +public record Application(String id, String name, Integer age, String created_at) { +} diff --git a/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/ApplicationWithAnnotation.java b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/ApplicationWithAnnotation.java new file mode 100644 index 0000000000..a0cd158843 --- /dev/null +++ b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/ApplicationWithAnnotation.java @@ -0,0 +1,8 @@ +package com.baeldung.java.io.pojotocsv; + +import com.opencsv.bean.CsvBindByName; +import com.opencsv.bean.CsvBindByPosition; + +public record ApplicationWithAnnotation(@CsvBindByName(column = "id", required = true) @CsvBindByPosition(position = 1) String id, @CsvBindByName(column = "name", required = true) @CsvBindByPosition(position = 0) String name, + @CsvBindByName(column = "age", required = true) @CsvBindByPosition(position = 2) Integer age, @CsvBindByName(column = "position", required = true) @CsvBindByPosition(position = 3) String created_at) { +} \ No newline at end of file diff --git a/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/BeanToCsv.java b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/BeanToCsv.java new file mode 100644 index 0000000000..f66c16beda --- /dev/null +++ b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/BeanToCsv.java @@ -0,0 +1,55 @@ +package com.baeldung.java.io.pojotocsv; + +import java.io.FileWriter; +import java.io.IOException; +import java.util.List; + +import com.opencsv.CSVWriter; +import com.opencsv.bean.StatefulBeanToCsvBuilder; +import com.opencsv.exceptions.CsvDataTypeMismatchException; +import com.opencsv.exceptions.CsvRequiredFieldEmptyException; + +public class BeanToCsv { + + public void beanToCSVWithDefault(List applications) throws Exception { + try (FileWriter writer = new FileWriter("src/main/resources/application.csv")) { + var builder = new StatefulBeanToCsvBuilder(writer).withQuotechar(CSVWriter.NO_QUOTE_CHARACTER) + .withSeparator(',') + .build(); + builder.write(applications); + } + } + + public void beanToCSVWithCustomHeaderStrategy(List applications) throws IOException, CsvRequiredFieldEmptyException, CsvDataTypeMismatchException { + try (FileWriter writer = new FileWriter("src/main/resources/application2.csv")) { + var mappingStrategy = new CustomHeaderStrategy(); + mappingStrategy.setType(Application.class); + + var builder = new StatefulBeanToCsvBuilder(writer).withQuotechar(CSVWriter.NO_QUOTE_CHARACTER) + .withMappingStrategy(mappingStrategy) + .build(); + builder.write(applications); + } + } + + public void beanToCSVWithCustomPositionStrategy(List applications) throws Exception { + try (FileWriter writer = new FileWriter("src/main/resources/application3.csv")) { + var builder = new StatefulBeanToCsvBuilder(writer).withQuotechar(CSVWriter.NO_QUOTE_CHARACTER) + .build(); + builder.write(applications); + } + } + + public void beanToCSVWithCustomHeaderAndPositionStrategy(List applications) throws IOException, CsvRequiredFieldEmptyException, CsvDataTypeMismatchException { + try (FileWriter writer = new FileWriter("src/main/resources/application4.csv")) { + var mappingStrategy = new CustomColumnPositionStrategy(); + mappingStrategy.setType(ApplicationWithAnnotation.class); + + var builder = new StatefulBeanToCsvBuilder(writer).withQuotechar(CSVWriter.NO_QUOTE_CHARACTER) + .withMappingStrategy(mappingStrategy) + .build(); + builder.write(applications); + } + } + +} diff --git a/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/CustomColumnPositionStrategy.java b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/CustomColumnPositionStrategy.java new file mode 100644 index 0000000000..204bf3f917 --- /dev/null +++ b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/CustomColumnPositionStrategy.java @@ -0,0 +1,12 @@ +package com.baeldung.java.io.pojotocsv; + +import com.opencsv.bean.ColumnPositionMappingStrategy; +import com.opencsv.exceptions.CsvRequiredFieldEmptyException; + +public class CustomColumnPositionStrategy extends ColumnPositionMappingStrategy { + @Override + public String[] generateHeader(T bean) throws CsvRequiredFieldEmptyException { + super.generateHeader(bean); + return super.getColumnMapping(); + } +} diff --git a/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/CustomHeaderStrategy.java b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/CustomHeaderStrategy.java new file mode 100644 index 0000000000..8e81c8ec28 --- /dev/null +++ b/libraries-io/src/main/java/com/baeldung/java/io/pojotocsv/CustomHeaderStrategy.java @@ -0,0 +1,16 @@ +package com.baeldung.java.io.pojotocsv; + +import java.util.Arrays; + +import com.opencsv.bean.HeaderColumnNameMappingStrategy; +import com.opencsv.exceptions.CsvRequiredFieldEmptyException; + +public class CustomHeaderStrategy extends HeaderColumnNameMappingStrategy { + @Override + public String[] generateHeader(T bean) throws CsvRequiredFieldEmptyException { + String[] header = super.generateHeader(bean); + return Arrays.stream(header) + .map(String::toLowerCase) + .toArray(String[]::new); + } +} diff --git a/libraries-io/src/main/resources/application.csv b/libraries-io/src/main/resources/application.csv new file mode 100644 index 0000000000..d4040e18e1 --- /dev/null +++ b/libraries-io/src/main/resources/application.csv @@ -0,0 +1,4 @@ +AGE,CREATED_AT,ID,NAME +34,2023-08-11,123,Sam +44,2023-02-11,456,Tam +54,2023-03-11,890,Jam diff --git a/libraries-io/src/main/resources/application2.csv b/libraries-io/src/main/resources/application2.csv new file mode 100644 index 0000000000..92bbced703 --- /dev/null +++ b/libraries-io/src/main/resources/application2.csv @@ -0,0 +1,4 @@ +age,created_at,id,name +34,2023-08-11,123,Sam +44,2023-02-11,456,Tam +54,2023-03-11,890,Jam diff --git a/libraries-io/src/main/resources/application3.csv b/libraries-io/src/main/resources/application3.csv new file mode 100644 index 0000000000..165107b103 --- /dev/null +++ b/libraries-io/src/main/resources/application3.csv @@ -0,0 +1,3 @@ +Sam,123,34,2023-08-11 +Tam,456,44,2023-02-11 +Jam,789,54,2023-03-11 diff --git a/libraries-io/src/main/resources/application4.csv b/libraries-io/src/main/resources/application4.csv new file mode 100644 index 0000000000..b7999ae227 --- /dev/null +++ b/libraries-io/src/main/resources/application4.csv @@ -0,0 +1,4 @@ +name,id,age,created_at +Sam,123,34,2023-08-11 +Tam,456,44,2023-02-11 +Jam,789,54,2023-03-11 diff --git a/libraries-io/src/test/java/com/baeldung/java/io/pojotocsv/BeanToCsvUnitTest.java b/libraries-io/src/test/java/com/baeldung/java/io/pojotocsv/BeanToCsvUnitTest.java new file mode 100644 index 0000000000..50cd1b1e0e --- /dev/null +++ b/libraries-io/src/test/java/com/baeldung/java/io/pojotocsv/BeanToCsvUnitTest.java @@ -0,0 +1,80 @@ +package com.baeldung.java.io.pojotocsv; + +import static org.assertj.core.api.AssertionsForClassTypes.assertThat; + +import java.io.BufferedReader; +import java.nio.file.Files; +import java.nio.file.Path; +import java.util.ArrayList; +import java.util.List; + +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +public class BeanToCsvUnitTest { + + List applications = new ArrayList<>(); + List applicationsWithAnnotation = new ArrayList<>(); + + @BeforeEach + public void beforeEach() { + applications = List.of(new Application("123", "Sam", 34, "2023-08-11"), new Application("456", "Tam", 44, "2023-02-11"), new Application("890", "Jam", 54, "2023-03-11")); + + applicationsWithAnnotation = List.of(new ApplicationWithAnnotation("123", "Sam", 34, "2023-08-11"), new ApplicationWithAnnotation("456", "Tam", 44, "2023-02-11"), new ApplicationWithAnnotation("789", "Jam", 54, "2023-03-11")); + } + + @Test + public void givenApplicationPOJO_whenUsingDefaultStrategy_thenReceiveCSVFormatWithAscendingOrderOfField() throws Exception { + BeanToCsv beanToCsv = new BeanToCsv(); + beanToCsv.beanToCSVWithDefault(applications); + try (BufferedReader bufferedReader = Files.newBufferedReader(Path.of("src/main/resources/application.csv"))) { + List content = bufferedReader.lines() + .toList(); + assertThat(content.get(0)).isEqualTo("AGE,CREATED_AT,ID,NAME"); + assertThat(content.get(1)).isEqualTo("34,2023-08-11,123,Sam"); + assertThat(content.get(2)).isEqualTo("44,2023-02-11,456,Tam"); + assertThat(content.get(3)).isEqualTo("54,2023-03-11,890,Jam"); + } + } + + @Test + public void givenApplicationPOJO_whenUsingCustomHeaderStrategy_thenReceiveCSVFormatWithCustomHeaders() throws Exception { + BeanToCsv beanToCsv = new BeanToCsv(); + beanToCsv.beanToCSVWithCustomHeaderStrategy(applications); + try (BufferedReader bufferedReader = Files.newBufferedReader(Path.of("src/main/resources/application2.csv"))) { + List content = bufferedReader.lines() + .toList(); + assertThat(content.get(0)).isEqualTo("age,created_at,id,name"); + assertThat(content.get(1)).isEqualTo("34,2023-08-11,123,Sam"); + assertThat(content.get(2)).isEqualTo("44,2023-02-11,456,Tam"); + assertThat(content.get(3)).isEqualTo("54,2023-03-11,890,Jam"); + } + } + + @Test + public void givenApplicationPOJOWithAnnotation_whenUsingCustomPositionStrategy_thenReceiveCSVFormatWithCustomPosition() throws Exception { + BeanToCsv beanToCsv = new BeanToCsv(); + beanToCsv.beanToCSVWithCustomPositionStrategy(applicationsWithAnnotation); + try (BufferedReader bufferedReader = Files.newBufferedReader(Path.of("src/main/resources/application3.csv"))) { + List content = bufferedReader.lines() + .toList(); + assertThat(content.get(0)).isEqualTo("Sam,123,34,2023-08-11"); + assertThat(content.get(1)).isEqualTo("Tam,456,44,2023-02-11"); + assertThat(content.get(2)).isEqualTo("Jam,789,54,2023-03-11"); + } + } + + @Test + public void givenApplicationPOJOWithAnnotation_whenUsingCustomHeaderPositionStrategy_thenReceiveCSVFormatWithCustomHeaderPosition() throws Exception { + BeanToCsv beanToCsv = new BeanToCsv(); + beanToCsv.beanToCSVWithCustomHeaderAndPositionStrategy(applicationsWithAnnotation); + try (BufferedReader bufferedReader = Files.newBufferedReader(Path.of("src/main/resources/application4.csv"))) { + List content = bufferedReader.lines() + .toList(); + assertThat(content.get(0)).isEqualTo("name,id,age,created_at"); + assertThat(content.get(1)).isEqualTo("Sam,123,34,2023-08-11"); + assertThat(content.get(2)).isEqualTo("Tam,456,44,2023-02-11"); + assertThat(content.get(3)).isEqualTo("Jam,789,54,2023-03-11"); + } + } +}