BAEL-87 - @JsonComponent in Spring Boot (eugenp#1519)

Author: wimdeblauwe

spring-boot/src/main/java/org/baeldung/jsoncomponent/User.java

@@ -0,0 +1,15 @@
+package org.baeldung.jsoncomponent;
+
+import javafx.scene.paint.Color;
+
+public class User {
+    private final Color favoriteColor;
+
+    public User(Color favoriteColor) {
+        this.favoriteColor = favoriteColor;
+    }
+
+    public Color getFavoriteColor() {
+        return favoriteColor;
+    }
+}

spring-boot/src/main/java/org/baeldung/jsoncomponent/UserCombinedSerializer.java

@@ -0,0 +1,46 @@
+package org.baeldung.jsoncomponent;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.TreeNode;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.node.TextNode;
+import javafx.scene.paint.Color;
+import org.springframework.boot.jackson.JsonComponent;
+
+import java.io.IOException;
+
+@JsonComponent
+public class UserCombinedSerializer {
+    public static class UserJsonSerializer extends JsonSerializer<User> {
+
+        @Override
+        public void serialize(User user, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
+            jsonGenerator.writeStartObject();
+            jsonGenerator.writeStringField("favoriteColor",
+                                           getColorAsWebColor(user.getFavoriteColor()));
+            jsonGenerator.writeEndObject();
+        }
+
+        private static String getColorAsWebColor(Color color) {
+            int r = (int) Math.round(color.getRed() * 255.0);
+            int g = (int) Math.round(color.getGreen() * 255.0);
+            int b = (int) Math.round(color.getBlue() * 255.0);
+            return String.format("#%02x%02x%02x", r, g, b);
+        }
+    }
+
+    @JsonComponent
+    public static class UserJsonDeserializer extends JsonDeserializer<User> {
+        @Override
+        public User deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
+            TreeNode treeNode = jsonParser.getCodec().readTree(jsonParser);
+            TextNode favoriteColor = (TextNode) treeNode.get("favoriteColor");
+            return new User(Color.web(favoriteColor.asText()));
+        }
+    }
+}

spring-boot/src/main/java/org/baeldung/jsoncomponent/UserJsonDeserializer.java

@@ -0,0 +1,22 @@
+package org.baeldung.jsoncomponent;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.TreeNode;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+import com.fasterxml.jackson.databind.node.TextNode;
+import javafx.scene.paint.Color;
+import org.springframework.boot.jackson.JsonComponent;
+
+import java.io.IOException;
+
+@JsonComponent
+public class UserJsonDeserializer extends JsonDeserializer<User> {
+    @Override
+    public User deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
+        TreeNode treeNode = jsonParser.getCodec().readTree(jsonParser);
+        TextNode favoriteColor = (TextNode) treeNode.get("favoriteColor");
+        return new User(Color.web(favoriteColor.asText()));
+    }
+}

spring-boot/src/main/java/org/baeldung/jsoncomponent/UserJsonSerializer.java

@@ -0,0 +1,29 @@
+package org.baeldung.jsoncomponent;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import javafx.scene.paint.Color;
+import org.springframework.boot.jackson.JsonComponent;
+
+import java.io.IOException;
+
+@JsonComponent
+public class UserJsonSerializer extends JsonSerializer<User> {
+
+    @Override
+    public void serialize(User user, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
+        jsonGenerator.writeStartObject();
+        jsonGenerator.writeStringField("favoriteColor",
+                                       getColorAsWebColor(user.getFavoriteColor()));
+        jsonGenerator.writeEndObject();
+    }
+
+    private static String getColorAsWebColor(Color color) {
+        int r = (int) Math.round(color.getRed() * 255.0);
+        int g = (int) Math.round(color.getGreen() * 255.0);
+        int b = (int) Math.round(color.getBlue() * 255.0);
+        return String.format("#%02x%02x%02x", r, g, b);
+    }
+}

spring-boot/src/test/java/org/baeldung/jsoncomponent/UserJsonDeserializerTest.java

@@ -0,0 +1,27 @@
+package org.baeldung.jsoncomponent;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import javafx.scene.paint.Color;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.json.JsonTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import java.io.IOException;
+
+import static org.junit.Assert.assertEquals;
+
+@JsonTest
+@RunWith(SpringRunner.class)
+public class UserJsonDeserializerTest {
+
+    @Autowired
+    private ObjectMapper objectMapper;
+
+    @Test
+    public void testDeserialize() throws IOException {
+        User user = objectMapper.readValue("{\"favoriteColor\":\"#f0f8ff\"}", User.class);
+        assertEquals(Color.ALICEBLUE, user.getFavoriteColor());
+    }
+}

spring-boot/src/test/java/org/baeldung/jsoncomponent/UserJsonSerializerTest.java

@@ -0,0 +1,27 @@
+package org.baeldung.jsoncomponent;
+
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import javafx.scene.paint.Color;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.json.JsonTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertEquals;
+
+@JsonTest
+@RunWith(SpringRunner.class)
+public class UserJsonSerializerTest {
+
+    @Autowired
+    private ObjectMapper objectMapper;
+
+    @Test
+    public void testSerialization() throws JsonProcessingException {
+        String json = objectMapper.writeValueAsString(new User(Color.ALICEBLUE));
+        assertEquals("{\"favoriteColor\":\"#f0f8ff\"}", json);
+    }
+}