custom serializer work

hgregoire · Jan 11, 2014 · a47c533 · a47c533
1 parent c905b21
commit a47c533
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Showing 6 changed files with 162 additions and 40 deletions.
diff --git a/jackson/pom.xml b/jackson/pom.xml
@@ -27,6 +27,12 @@
             <version>4.0</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+
         <!-- web -->
 
         <!-- marshalling -->

diff --git a/jackson/src/test/java/org/baeldung/jackson/dtos/Item.java b/jackson/src/test/java/org/baeldung/jackson/dtos/Item.java
@@ -0,0 +1,28 @@
+package org.baeldung.jackson.dtos;
+
+public class Item {
+    public final int id;
+    public final String itemNr;
+    public final User createdBy;
+
+    public Item(final int id, final String itemNr, final User createdBy) {
+        this.id = id;
+        this.itemNr = itemNr;
+        this.createdBy = createdBy;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getItemNr() {
+        return itemNr;
+    }
+
+    public User getCreatedBy() {
+        return createdBy;
+    }
+
+}
diff --git a/jackson/src/test/java/org/baeldung/jackson/dtos/User.java b/jackson/src/test/java/org/baeldung/jackson/dtos/User.java
@@ -0,0 +1,22 @@
+package org.baeldung.jackson.dtos;
+
+public class User {
+    public final int id;
+    public final String name;
+
+    public User(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+}
diff --git a/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationEnumsUnitTest.java b/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationEnumsUnitTest.java
@@ -0,0 +1,57 @@
+package org.baeldung.jackson.test;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.junit.Assert.assertThat;
+
+import java.io.IOException;
+
+import org.baeldung.jackson.dtos.withEnum.MyDtoWithEnum;
+import org.baeldung.jackson.dtos.withEnum.MyDtoWithEnumCustom;
+import org.baeldung.jackson.dtos.withEnum.TypeEnum;
+import org.baeldung.jackson.dtos.withEnum.TypeEnumWithCustomSerializer;
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class JacksonSerializationEnumsUnitTest {
+
+    // tests - enums
+
+    @Test
+    public final void whenSerializingSimpleEnum_thenCorrect() throws JsonParseException, IOException {
+        final ObjectMapper mapper = new ObjectMapper();
+        final String dtoAsString = mapper.writeValueAsString(TypeEnum.TYPE1);
+
+        System.out.println(dtoAsString);
+        assertThat(dtoAsString, containsString("\"name\":\"Type A\""));
+    }
+
+    @Test
+    public final void whenSerializingEntityWithEnum_thenCorrect() throws JsonParseException, IOException {
+        final ObjectMapper mapper = new ObjectMapper();
+        final String dtoAsString = mapper.writeValueAsString(new MyDtoWithEnum("a", 1, true, TypeEnum.TYPE1));
+
+        System.out.println(dtoAsString);
+        assertThat(dtoAsString, containsString("\"name\":\"Type A\""));
+    }
+
+    @Test
+    public final void givenCustomSerializer_whenSerializingEntityWithEnum_thenCorrect() throws JsonParseException, IOException {
+        final ObjectMapper mapper = new ObjectMapper();
+        final String dtoAsString = mapper.writeValueAsString(new MyDtoWithEnumCustom("a", 1, true, TypeEnumWithCustomSerializer.TYPE1));
+
+        System.out.println(dtoAsString);
+        assertThat(dtoAsString, containsString("\"name\":\"Type A\""));
+    }
+
+    @Test
+    public final void whenSerializingArrayOfEnums_thenCorrect() throws JsonParseException, IOException {
+        final ObjectMapper mapper = new ObjectMapper();
+        final String json = mapper.writeValueAsString(new TypeEnum[] { TypeEnum.TYPE1, TypeEnum.TYPE2 });
+
+        System.out.println(json);
+        assertThat(json, containsString("\"name\":\"Type A\""));
+    }
+
+}
diff --git a/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationUnitTest.java b/jackson/src/test/java/org/baeldung/jackson/test/JacksonSerializationUnitTest.java
@@ -1,28 +1,33 @@
 package org.baeldung.jackson.test;
 
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
+import static org.apache.commons.lang3.RandomStringUtils.randomNumeric;
 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.io.StringWriter;
 import java.util.List;
 
+import org.baeldung.jackson.dtos.Item;
 import org.baeldung.jackson.dtos.MyDto;
 import org.baeldung.jackson.dtos.MyDtoFieldNameChanged;
 import org.baeldung.jackson.dtos.MyDtoNoAccessors;
 import org.baeldung.jackson.dtos.MyDtoNoAccessorsAndFieldVisibility;
-import org.baeldung.jackson.dtos.withEnum.MyDtoWithEnum;
-import org.baeldung.jackson.dtos.withEnum.MyDtoWithEnumCustom;
-import org.baeldung.jackson.dtos.withEnum.TypeEnum;
-import org.baeldung.jackson.dtos.withEnum.TypeEnumWithCustomSerializer;
+import org.baeldung.jackson.dtos.User;
+import org.baeldung.jackson.try1.ItemSerializer;
 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.core.Version;
 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 JacksonSerializationUnitTest {
@@ -82,54 +87,35 @@ public final void givenObjectHasNoAccessorsButHasVisibleFields_whenSerializing_t
         assertThat(dtoAsString, containsString("booleanValue"));
     }
 
-    // tests - enums
-
-    @Test
-    public final void whenSerializingSimpleEnum_thenCorrect() throws JsonParseException, IOException {
-        final ObjectMapper mapper = new ObjectMapper();
-        final String dtoAsString = mapper.writeValueAsString(TypeEnum.TYPE1);
-
-        System.out.println(dtoAsString);
-        assertThat(dtoAsString, containsString("\"name\":\"Type A\""));
-    }
-
-    @Test
-    public final void whenSerializingEntityWithEnum_thenCorrect() throws JsonParseException, IOException {
-        final ObjectMapper mapper = new ObjectMapper();
-        final String dtoAsString = mapper.writeValueAsString(new MyDtoWithEnum("a", 1, true, TypeEnum.TYPE1));
-
-        System.out.println(dtoAsString);
-        assertThat(dtoAsString, containsString("\"name\":\"Type A\""));
-    }
+    // tests - multiple entities to json
 
     @Test
-    public final void givenCustomSerializer_whenSerializingEntityWithEnum_thenCorrect() throws JsonParseException, IOException {
-        final ObjectMapper mapper = new ObjectMapper();
-        final String dtoAsString = mapper.writeValueAsString(new MyDtoWithEnumCustom("a", 1, true, TypeEnumWithCustomSerializer.TYPE1));
-
-        System.out.println(dtoAsString);
-        assertThat(dtoAsString, containsString("\"name\":\"Type A\""));
-    }
+    public final void whenDtoIsSerialized_thenCorrect() throws JsonParseException, IOException {
+        final List<MyDto> listOfDtos = Lists.newArrayList(new MyDto("a", 1, true), new MyDto("bc", 3, false));
 
-    @Test
-    public final void whenSerializingArrayOfEnums_thenCorrect() throws JsonParseException, IOException {
         final ObjectMapper mapper = new ObjectMapper();
-        final String json = mapper.writeValueAsString(new TypeEnum[] { TypeEnum.TYPE1, TypeEnum.TYPE2 });
+        final String dtosAsString = mapper.writeValueAsString(listOfDtos);
 
-        System.out.println(json);
-        assertThat(json, containsString("\"name\":\"Type A\""));
+        System.out.println(dtosAsString);
     }
 
-    // tests - multiple entities to json
+    // tests - custom serializer
 
     @Test
-    public final void whenDtoIsSerialized_thenCorrect() throws JsonParseException, IOException {
-        final List<MyDto> listOfDtos = Lists.newArrayList(new MyDto("a", 1, true), new MyDto("bc", 3, false));
+    public final void whenSerializingWithCustomSerializer_thenNoExceptions() throws JsonGenerationException, JsonMappingException, IOException {
+        final Item myItem = new Item(Integer.parseInt(randomNumeric(2)), randomAlphabetic(8), new User(Integer.parseInt(randomNumeric(2)), randomAlphabetic(8)));
 
         final ObjectMapper mapper = new ObjectMapper();
-        final String dtosAsString = mapper.writeValueAsString(listOfDtos);
 
-        System.out.println(dtosAsString);
+        final SimpleModule simpleModule = new SimpleModule("SimpleModule", new Version(1, 0, 0, null));
+        simpleModule.addSerializer(Item.class, new ItemSerializer());
+        // simpleModule.addSerializer(User.class, new UserSerializer());
+        mapper.registerModule(simpleModule);
+
+        final StringWriter writer = new StringWriter();
+        mapper.writeValue(writer, myItem);
+        final String serialized = writer.toString();
+        System.out.println(serialized);
     }
 
 }
diff --git a/jackson/src/test/java/org/baeldung/jackson/try1/ItemSerializer.java b/jackson/src/test/java/org/baeldung/jackson/try1/ItemSerializer.java
@@ -0,0 +1,23 @@
+package org.baeldung.jackson.try1;
+
+import java.io.IOException;
+
+import org.baeldung.jackson.dtos.Item;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+
+public class ItemSerializer extends JsonSerializer<Item> {
+
+    @Override
+    public final void serialize(final Item value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException, JsonProcessingException {
+        jgen.writeStartObject();
+        jgen.writeNumberField("id", value.id);
+        jgen.writeStringField("itemNr", value.itemNr);
+        jgen.writeNumberField("createdBy", value.createdBy.id);
+        jgen.writeEndObject();
+    }
+
+}