RabbitMQ学习之messageconver插件实现(Gson)

来源：互联网发布：kali linux洪水攻击编辑：程序博客网时间：2024/06/07 02:01

RabbitMQ已经实现了Jackson的消息转换（Jackson2JsonMessageConverter），由于考虑到效率，如下使用Gson实现消息转换。

如下消息的转换类的接口MessageConverter，Jackson2JsonMessageConverter的父类AbstractJsonMessageConverter针对json转换的基类。

我们实现Gson2JsonMessageConverter转换类也继承AbstractJsonMessageConverter。

引入Gson的pom

<dependency><groupId>com.google.code.gson</groupId><artifactId>gson</artifactId><version>2.3</version></dependency>

转换类实现如下：

package cn.slimsmart.rabbitmq.demo.spring.tag;import java.io.IOException;import java.io.UnsupportedEncodingException;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.springframework.amqp.core.Message;import org.springframework.amqp.core.MessageProperties;import org.springframework.amqp.support.converter.AbstractJsonMessageConverter;import org.springframework.amqp.support.converter.ClassMapper;import org.springframework.amqp.support.converter.DefaultClassMapper;import org.springframework.amqp.support.converter.MessageConversionException;import com.google.gson.Gson;public class Gson2JsonMessageConverter extends AbstractJsonMessageConverter {private static Log log = LogFactory.getLog(Gson2JsonMessageConverter.class);private static  ClassMapper classMapper =  new DefaultClassMapper();private static Gson gson = new Gson();public Gson2JsonMessageConverter() {super();}@Overrideprotected Message createMessage(Object object,MessageProperties messageProperties) {byte[] bytes = null;try {String jsonString = gson.toJson(object);bytes = jsonString.getBytes(getDefaultCharset());}catch (IOException e) {throw new MessageConversionException("Failed to convert Message content", e);}messageProperties.setContentType(MessageProperties.CONTENT_TYPE_JSON);messageProperties.setContentEncoding(getDefaultCharset());if (bytes != null) {messageProperties.setContentLength(bytes.length);}classMapper.fromClass(object.getClass(),messageProperties);return new Message(bytes, messageProperties);}@Overridepublic Object fromMessage(Message message)throws MessageConversionException {Object content = null;MessageProperties properties = message.getMessageProperties();if (properties != null) {String contentType = properties.getContentType();if (contentType != null && contentType.contains("json")) {String encoding = properties.getContentEncoding();if (encoding == null) {encoding = getDefaultCharset();}try {Class<?> targetClass = getClassMapper().toClass(message.getMessageProperties());content = convertBytesToObject(message.getBody(),encoding, targetClass);}catch (IOException e) {throw new MessageConversionException("Failed to convert Message content", e);}}else {log.warn("Could not convert incoming message with content-type ["+ contentType + "]");}}if (content == null) {content = message.getBody();}return content;}private Object convertBytesToObject(byte[] body, String encoding,Class<?> clazz) throws UnsupportedEncodingException {String contentAsString = new String(body, encoding);return gson.fromJson(contentAsString, clazz);}}

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