[BAEL-19673] - Move articles out of jackson part 1

2019-11-22 14:52:42 +02:00
parent dd9a7593c1
commit 6eb57f91eb
97 changed files with 894 additions and 210 deletions
@@ -0,0 +1,195 @@
+package com.baeldung.exceptions;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.baeldung.exceptions.User;
+import com.baeldung.exceptions.UserWithPrivateFields;
+import com.baeldung.exceptions.UserWithRoot;
+import com.baeldung.exceptions.Zoo;
+import com.baeldung.exceptions.ZooConfigured;
+import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException;
+
+public class JacksonExceptionsUnitTest {
+
+    // JsonMappingException: Can not construct instance of
+    @Test(expected = JsonMappingException.class)
+    public void givenAbstractClass_whenDeserializing_thenException() throws IOException {
+        final String json = "{\"animal\":{\"name\":\"lacy\"}}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        mapper.reader()
+            .forType(Zoo.class)
+            .readValue(json);
+    }
+
+    @Test
+    public void givenAbstractClassConfigured_whenDeserializing_thenCorrect() throws IOException {
+        final String json = "{\"animal\":{\"name\":\"lacy\"}}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        mapper.reader()
+            .forType(ZooConfigured.class)
+            .readValue(json);
+    }
+
+    // JsonMappingException: No serializer found for class
+    @Test(expected = JsonMappingException.class)
+    public void givenClassWithPrivateFields_whenSerializing_thenException() throws IOException {
+        final UserWithPrivateFields user = new UserWithPrivateFields(1, "John");
+
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.writer()
+            .writeValueAsString(user);
+    }
+
+    @Test
+    public void givenClassWithPrivateFields_whenConfigureSerializing_thenCorrect() throws IOException {
+        final UserWithPrivateFields user = new UserWithPrivateFields(1, "John");
+
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.setVisibility(PropertyAccessor.FIELD, Visibility.ANY);
+
+        final String result = mapper.writer()
+            .writeValueAsString(user);
+        assertThat(result, containsString("John"));
+    }
+
+    // JsonMappingException: No suitable constructor found
+    @Test(expected = JsonMappingException.class)
+    public void givenNoDefaultConstructor_whenDeserializing_thenException() throws IOException {
+        final String json = "{\"id\":1,\"name\":\"John\"}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        mapper.reader()
+            .forType(UserWithNoDefaultConstructor.class)
+            .readValue(json);
+    }
+
+    @Test
+    public void givenDefaultConstructor_whenDeserializing_thenCorrect() throws IOException {
+        final String json = "{\"id\":1,\"name\":\"John\"}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final User user = mapper.reader()
+            .forType(User.class)
+            .readValue(json);
+        assertEquals("John", user.name);
+    }
+
+    // JsonMappingException: Root name does not match expected
+    @Test(expected = JsonMappingException.class)
+    public void givenWrappedJsonString_whenDeserializing_thenException() throws IOException {
+        final String json = "{\"user\":{\"id\":1,\"name\":\"John\"}}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.enable(DeserializationFeature.UNWRAP_ROOT_VALUE);
+
+        mapper.reader()
+            .forType(User.class)
+            .readValue(json);
+    }
+
+    @Test
+    public void givenWrappedJsonStringAndConfigureClass_whenDeserializing_thenCorrect() throws IOException {
+        final String json = "{\"user\":{\"id\":1,\"name\":\"John\"}}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.enable(DeserializationFeature.UNWRAP_ROOT_VALUE);
+
+        final UserWithRoot user = mapper.reader()
+            .forType(UserWithRoot.class)
+            .readValue(json);
+        assertEquals("John", user.name);
+    }
+
+    // JsonMappingException: Can not deserialize instance of
+    @Test(expected = JsonMappingException.class)
+    public void givenJsonOfArray_whenDeserializing_thenException() throws JsonProcessingException, IOException {
+        final String json = "[{\"id\":1,\"name\":\"John\"},{\"id\":2,\"name\":\"Adam\"}]";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        mapper.reader()
+            .forType(User.class)
+            .readValue(json);
+    }
+
+    @Test
+    public void givenJsonOfArray_whenDeserializing_thenCorrect() throws JsonProcessingException, IOException {
+        final String json = "[{\"id\":1,\"name\":\"John\"},{\"id\":2,\"name\":\"Adam\"}]";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final List<User> users = mapper.reader()
+            .forType(new TypeReference<List<User>>() {
+            })
+            .readValue(json);
+
+        assertEquals(2, users.size());
+    }
+
+    // UnrecognizedPropertyException
+    @Test(expected = UnrecognizedPropertyException.class)
+    public void givenJsonStringWithExtra_whenDeserializing_thenException() throws IOException {
+        final String json = "{\"id\":1,\"name\":\"John\", \"checked\":true}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.reader()
+            .forType(User.class)
+            .readValue(json);
+    }
+
+    @Test
+    public void givenJsonStringWithExtra_whenConfigureDeserializing_thenCorrect() throws IOException {
+        final String json = "{\"id\":1,\"name\":\"John\", \"checked\":true}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
+
+        final User user = mapper.reader()
+            .forType(User.class)
+            .readValue(json);
+        assertEquals("John", user.name);
+    }
+
+    // JsonParseException: Unexpected character (''' (code 39))
+    @Test(expected = JsonParseException.class)
+    public void givenStringWithSingleQuotes_whenDeserializing_thenException() throws JsonProcessingException, IOException {
+        final String json = "{'id':1,'name':'John'}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        mapper.reader()
+            .forType(User.class)
+            .readValue(json);
+    }
+
+    @Test
+    public void givenStringWithSingleQuotes_whenConfigureDeserializing_thenCorrect() throws JsonProcessingException, IOException {
+        final String json = "{'id':1,'name':'John'}";
+
+        final JsonFactory factory = new JsonFactory();
+        factory.enable(JsonParser.Feature.ALLOW_SINGLE_QUOTES);
+        final ObjectMapper mapper = new ObjectMapper(factory);
+
+        final User user = mapper.reader()
+            .forType(User.class)
+            .readValue(json);
+        assertEquals("John", user.name);
+    }
+
+}
@@ -0,0 +1,51 @@
+package com.baeldung.mappingexception;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+
+import java.io.IOException;
+import java.util.List;
+import org.junit.Test;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.core.JsonGenerationException;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.google.common.collect.Lists;
+
+public class JacksonMappingExceptionUnitTest {
+
+    @Test(expected = JsonMappingException.class)
+    public final void givenObjectHasNoAccessors_whenSerializing_thenException() throws JsonParseException, IOException {
+        final String dtoAsString = new ObjectMapper().writeValueAsString(new MyDtoNoAccessors());
+
+        assertThat(dtoAsString, notNullValue());
+    }
+
+    @Test
+    public final void givenObjectHasNoAccessors_whenSerializingWithPrivateFieldsVisibility_thenNoException() throws JsonParseException, IOException {
+        final ObjectMapper objectMapper = new ObjectMapper();
+        objectMapper.setVisibility(PropertyAccessor.FIELD, Visibility.ANY);
+        final String dtoAsString = objectMapper.writeValueAsString(new MyDtoNoAccessors());
+
+        assertThat(dtoAsString, containsString("intValue"));
+        assertThat(dtoAsString, containsString("stringValue"));
+        assertThat(dtoAsString, containsString("booleanValue"));
+    }
+
+    @Test
+    public final void givenObjectHasNoAccessorsButHasVisibleFields_whenSerializing_thenNoException() throws JsonParseException, IOException {
+        final ObjectMapper objectMapper = new ObjectMapper();
+        final String dtoAsString = objectMapper.writeValueAsString(new MyDtoNoAccessorsAndFieldVisibility());
+
+        assertThat(dtoAsString, containsString("intValue"));
+        assertThat(dtoAsString, containsString("stringValue"));
+        assertThat(dtoAsString, containsString("booleanValue"));
+    }
+
+}