Merge pull request #174 from gdgib/G2-1794-JacksonInjection

G2-1794 Jackson injection

Author: gdgib

gb-serdes/src/main/java/com/g2forge/gearbox/serdes/injection/HJackonInjection.java

@@ -0,0 +1,20 @@
+package com.g2forge.gearbox.serdes.injection;
+
+import java.util.Map;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationConfig;
+import com.fasterxml.jackson.databind.cfg.ContextAttributes;
+
+public class HJackonInjection {
+	public ObjectMapper with(ObjectMapper mapper, Map<String, ?> injectables) {
+		final SerializationConfig initialSerializationConfig = mapper.getSerializationConfig();
+		final ContextAttributes attributes = initialSerializationConfig.getAttributes();
+		final ContextAttributes attributesWithInjectedValue = attributes.withSharedAttributes(injectables);
+		final SerializationConfig serializationConfigWithInjectedValue = initialSerializationConfig.with(attributesWithInjectedValue);
+		
+		mapper.setInjectableValues(null);
+		
+		return mapper.setConfig(serializationConfigWithInjectedValue);
+	}
+}

gb-serdes/src/main/java/com/g2forge/gearbox/serdes/injection/JacksonInjectedValue.java

@@ -0,0 +1,67 @@
+package com.g2forge.gearbox.serdes.injection;
+
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.InjectableValues;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationConfig;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.cfg.ContextAttributes;
+import com.fasterxml.jackson.databind.exc.MissingInjectableValueExcepion;
+import com.g2forge.alexandria.java.type.ref.ITypeRef;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+
+@Data
+@Builder(toBuilder = true)
+@RequiredArgsConstructor
+public class JacksonInjectedValue<T> {
+	protected final String id;
+
+	protected final ITypeRef<T> type;
+
+	protected final T fallback;
+
+	public JacksonInjectedValue(Class<?> owner, String name, ITypeRef<T> type, T fallback) {
+		this(owner.getName() + "." + name, type, fallback);
+	}
+
+	public JacksonInjectedValue(Class<T> type, T fallback) {
+		this(type.getName(), ITypeRef.of(type), fallback);
+	}
+
+	public ObjectMapper inject(ObjectMapper mapper, T value) {
+		final SerializationConfig initialSerializationConfig = mapper.getSerializationConfig();
+		final ContextAttributes attributes = initialSerializationConfig.getAttributes();
+		final ContextAttributes attributesWithInjectedValue = attributes.withSharedAttribute(getId(), value);
+		final SerializationConfig serializationConfigWithInjectedValue = initialSerializationConfig.with(attributesWithInjectedValue);
+
+		final InjectableValues existingInjectableValues = mapper.getInjectableValues();
+		if (existingInjectableValues == null) mapper.setInjectableValues(new InjectableValues.Std().addValue(getId(), value));
+		else if (!(existingInjectableValues instanceof InjectableValues.Std)) throw new IllegalArgumentException();
+		else((InjectableValues.Std) existingInjectableValues).addValue(getId(), value);
+
+		return mapper.setConfig(serializationConfigWithInjectedValue);
+	}
+
+	public T get(SerializerProvider provider) {
+		final Object value = provider.getAttribute(getId());
+		if (value == null) return getFallback();
+		return getType().cast(value);
+	}
+
+	public T get(DeserializationContext context) {
+		final Object value;
+		try {
+			value = context.findInjectableValue(getId(), null, null, null, null);
+		} catch (MissingInjectableValueExcepion e) {
+			return getFallback();
+		} catch (JsonMappingException e) {
+			throw new IllegalStateException(e);
+		}
+		if (value == null) return getFallback();
+		return getType().cast(value);
+	}
+}

gb-serdes/src/test/java/com/g2forge/gearbox/serdes/injection/ExampleObject.java

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+package com.g2forge.gearbox.serdes.injection;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.g2forge.alexandria.java.function.IFunction1;
+import com.g2forge.alexandria.java.type.ref.ATypeRef;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.RequiredArgsConstructor;
+
+@Data
+@Builder(toBuilder = true)
+@RequiredArgsConstructor
+@JsonSerialize(using = ExampleObjectSerializer.class)
+@JsonDeserialize(using = ExampleObjectDeserializer.class)
+public class ExampleObject {
+	public static final JacksonInjectedValue<IFunction1<Integer, Integer>> PREPROCESSOR = new JacksonInjectedValue<>(ExampleObject.class, "preprocessor", new ATypeRef<IFunction1<Integer, Integer>>() {}, IFunction1.identity());
+
+	protected final Integer value;
+}

gb-serdes/src/test/java/com/g2forge/gearbox/serdes/injection/ExampleObjectDeserializer.java

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+package com.g2forge.gearbox.serdes.injection;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JacksonException;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+
+public class ExampleObjectDeserializer extends StdDeserializer<ExampleObject> {
+	private static final long serialVersionUID = 2867578675754843411L;
+
+	public ExampleObjectDeserializer() {
+		super(ExampleObject.class);
+	}
+
+	@Override
+	public ExampleObject deserialize(JsonParser parser, DeserializationContext context) throws IOException, JacksonException {
+		final JsonNode node = parser.getCodec().readTree(parser);
+		final int value = node.get("value").asInt();
+		return new ExampleObject(ExampleObject.PREPROCESSOR.get(context).apply(value));
+	}
+}

gb-serdes/src/test/java/com/g2forge/gearbox/serdes/injection/ExampleObjectSerializer.java

@@ -0,0 +1,23 @@
+package com.g2forge.gearbox.serdes.injection;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class ExampleObjectSerializer extends StdSerializer<ExampleObject> {
+	private static final long serialVersionUID = 7620126831613439913L;
+
+	public ExampleObjectSerializer() {
+		super(ExampleObject.class);
+	}
+
+	@Override
+	public void serialize(ExampleObject value, JsonGenerator jsonGenerator, SerializerProvider provider) throws IOException, JsonProcessingException {
+		jsonGenerator.writeStartObject();
+		jsonGenerator.writeNumberField("value", ExampleObject.PREPROCESSOR.get(provider).apply(value.getValue()));
+		jsonGenerator.writeEndObject();
+	}
+}

gb-serdes/src/test/java/com/g2forge/gearbox/serdes/injection/TestInjection.java

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+package com.g2forge.gearbox.serdes.injection;
+
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.g2forge.alexandria.test.HAssert;
+
+public class TestInjection {
+	@Test
+	public void noinjection() throws JsonMappingException, JsonProcessingException {
+		final ExampleObject actual = new ExampleObject(0);
+		final ObjectMapper mapper = new ObjectMapper();
+		HAssert.assertEquals(actual, mapper.readValue(mapper.writeValueAsString(actual), ExampleObject.class));
+	}
+
+	@Test
+	public void increment() throws JsonMappingException, JsonProcessingException {
+		final ObjectMapper mapper = ExampleObject.PREPROCESSOR.inject(new ObjectMapper(), x -> x + 1);;
+		HAssert.assertEquals(new ExampleObject(2), mapper.readValue(mapper.writeValueAsString(new ExampleObject(0)), ExampleObject.class));
+	}
+}