org.springframework.cloud.stream.converter.TupleJsonMessageConverter.java Source code

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Here is the source code for org.springframework.cloud.stream.converter.TupleJsonMessageConverter.java

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/*
 * Copyright 2015-2017 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.springframework.cloud.stream.converter;

import java.io.IOException;
import java.nio.charset.Charset;
import java.util.Arrays;

import com.fasterxml.jackson.databind.ObjectMapper;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.converter.AbstractMessageConverter;
import org.springframework.tuple.Tuple;
import org.springframework.tuple.TupleBuilder;
import org.springframework.util.MimeTypeUtils;

/**
 * A {@link org.springframework.messaging.converter.MessageConverter} to convert a
 * {@link Tuple} to a JSON String
 * @author David Turanski
 * @author Ilayaperumal Gopinathan
 * @author Marius Bogoevici
 */
public class TupleJsonMessageConverter extends AbstractMessageConverter {

    private final ObjectMapper objectMapper;

    @Value("${typeconversion.json.prettyPrint:false}")
    private volatile boolean prettyPrint;

    public TupleJsonMessageConverter(ObjectMapper objectMapper) {
        super(Arrays.asList(MessageConverterUtils.X_SPRING_TUPLE, MimeTypeUtils.APPLICATION_JSON));
        this.objectMapper = (objectMapper != null) ? objectMapper : new ObjectMapper();
    }

    public void setPrettyPrint(boolean prettyPrint) {
        this.prettyPrint = prettyPrint;
    }

    @Override
    protected boolean supports(Class<?> clazz) {
        return Tuple.class.isAssignableFrom(clazz);
    }

    @Override
    protected Object convertToInternal(Object payload, MessageHeaders headers, Object conversionHint) {
        Tuple t = (Tuple) payload;
        String json;
        if (this.prettyPrint) {
            try {
                Object tmp = this.objectMapper.readValue(t.toString(), Object.class);
                json = this.objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(tmp);
            } catch (IOException e) {
                this.logger.error(e.getMessage(), e);
                return null;
            }
        } else {
            json = t.toString();
        }
        return json;
    }

    @Override
    public Object convertFromInternal(Message<?> message, Class<?> targetClass, Object conversionHint) {
        String source;
        if (message.getPayload() instanceof byte[]) {
            source = new String((byte[]) message.getPayload(), Charset.forName("UTF-8"));
        } else {
            source = message.getPayload().toString();
        }
        return TupleBuilder.fromString(source);
    }

}