org.ratpackframework.jackson.JacksonModule.java Source code

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Here is the source code for org.ratpackframework.jackson.JacksonModule.java

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/*
 * Copyright 2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.ratpackframework.jackson;

import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
import com.fasterxml.jackson.core.util.MinimalPrettyPrinter;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectWriter;
import com.google.inject.AbstractModule;
import com.google.inject.Provides;
import com.google.inject.Scopes;
import org.ratpackframework.jackson.internal.DefaultJsonRenderer;

import javax.inject.Singleton;

/**
 * A Guice module that provides an implementation of {@link JsonRenderer}, a renderer for {@link Json} object.
 * <p>
 * Also provides a default instance of {@link ObjectMapper}, which is the engine for serialization, and an
 * instance of {@link ObjectWriter} derived from this which is used by the {@link JsonRenderer} implementation.
 * To globally customize JSON generation, It is usually sufficient to override the {@link ObjectMapper} binding.
 */
@SuppressWarnings("UnusedDeclaration")
public class JacksonModule extends AbstractModule {

    boolean prettyPrint;

    /**
     * Constructor.
     */
    public JacksonModule() {
    }

    /**
     * Constructor.
     *
     * @param prettyPrint initial pretty print value.
     */
    public JacksonModule(boolean prettyPrint) {
        this.prettyPrint = prettyPrint;
    }

    /**
     * Should the JSON be pretty printed.
     * <p>
     * Default is {@code false}.
     *
     * @return Should the JSON be pretty printed.
     */
    public boolean isPrettyPrint() {
        return prettyPrint;
    }

    /**
     * Sets if the JSON should be pretty printed.
     * <p>
     * See {@link DefaultPrettyPrinter} for formatting details.
     *
     * @param prettyPrint If the JSON should be pretty printed
     */
    public void setPrettyPrint(boolean prettyPrint) {
        this.prettyPrint = prettyPrint;
    }

    @Override
    protected void configure() {
        bind(JsonRenderer.class).to(DefaultJsonRenderer.class);
        bind(ObjectMapper.class).in(Scopes.SINGLETON);
    }

    /**
     * Creates an object writer based on the bound {@link ObjectMapper} and the {@link #isPrettyPrint()} value.
     *
     * @param objectMapper The object mapper.
     * @return An object writer.
     */
    @Provides
    @Singleton
    ObjectWriter objectWriter(ObjectMapper objectMapper) {
        return objectMapper.writer(isPrettyPrint() ? new DefaultPrettyPrinter() : new MinimalPrettyPrinter());
    }

}