Mule ESB 学习笔记（12）JSON转换器的使用

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           在许多情况下,可能需要把类转换为json,或者将json转换为xml,xlst等各种格式.这里简单讲解json和xml,xlst等之间的转换过程.

 

 

测试代码:

  XmlToJson transformer = new XmlToJson();
        String jsonResponse = (String) transformer.transform(XML);
        System.out.println("jsonResponse ="+jsonResponse);
        
        StringReader reader = new StringReader(XML);

        transformer = new XmlToJson();
        jsonResponse = (String) transformer.transform(reader);
        System.out.println("jsonResponse ="+jsonResponse);
        
        byte[] bytes = XML.getBytes();
        transformer = new XmlToJson();
        jsonResponse = (String) transformer.transform(bytes);
        System.out.println("jsonResponse ="+jsonResponse);
        
        Document document = XMLUtils.toW3cDocument(XML);
        document.setDocumentURI("xxx");
        transformer = new XmlToJson();
        jsonResponse = (String) transformer.transform(document);
        System.out.println("jsonResponse ="+jsonResponse);
        

  

 

mule-jdbc-json-config.xml:

 

服务端代码:

public class JSONJdbcServerMain
{

  public static void main(String[] args) {
      try {
          String configFile = "mule-jdbc-json-config.xml";
          String[] configFileArr = new String[] {configFile };
          MuleContextFactory muleContextFactory = new DefaultMuleContextFactory();
          MuleContext muleContext = muleContextFactory
                  .createMuleContext(new SpringXmlConfigurationBuilder(configFileArr));
          muleContext.start();
      } catch (Exception e) {
          e.printStackTrace();
      }
  
   }
}

 

客户端代码:

                        原来 Java 项目中用的 JSON 组件库主要是 Gson 和 json-lib，Gson 算是很错的库，json-lib 略显寒碜。好啦，最近 Play 2.x 中弃用了 Gson 而采纳了 Jackson，所以现在就来打探一下 Jackson，踩个点吧。

Jackson 号称非常高的性能，听说比另两位兄弟 Gson 和 json-lib 高出一大截，我没有亲测，可是有心人做了，看这个链接 两款JSON类库Jackson与JSON-lib的性能对比(新增第三款测试) 中的数据。2010 年 8 月份的测试结果，不知现在随着版本的变更是否仍然保持着这种悬殊。

 

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.StringRequestEntity;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.codehaus.jackson.annotate.JsonAutoDetect.Visibility;
import org.codehaus.jackson.annotate.JsonMethod;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;

/**
 * 
功能描述,该部分必须以中文句号结尾。

 *
 * 创建日期 2013-8-22

 * @author  $Author$

 * @version $Revision$ $Date$
 * @since   3.0.0
 */
public class MuleJSONJdbcClientMain {
    public static void main(String[] args) {
        // 构造HttpClient的实例
        HttpClient httpClient = new HttpClient();
        // 创建GET方法的实例
        PostMethod postMethod = new PostMethod("http://localhost:8081/httpPost");
        // 使用系统提供的默认的恢复策略
        postMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler());
        try {
            // 执行getMethod
            
            //将对象转换JSON
            ObjectMapper mapper = new ObjectMapper();
            mapper.setVisibility(JsonMethod.FIELD, Visibility.ANY);
            mapper.configure(SerializationConfig.Feature.INDENT_OUTPUT, true);
            Map paramMap=new HashMap();
            paramMap.put("id", "345");
            paramMap.put("name", "xiaobai");
            String jsonx = mapper.writeValueAsString(paramMap);
            
            //将json转换为对象
            Map map = mapper.readValue(jsonx, Map.class);
            System.out.println("map=" + map.toString());
            
            //设置JSON数据信息
            postMethod.setRequestEntity(new StringRequestEntity(jsonx));
            
            //发送http请求
            int statusCode = httpClient.executeMethod(postMethod);
            if (statusCode != HttpStatus.SC_OK) {
                System.err.println("Method failed: " + postMethod.getStatusLine());
            }
            // 读取内容
            byte[] inputStream = postMethod.getResponseBody();
            // 处理内容
            System.out.println("responseBody=" + new String(inputStream, "UTF-8"));
        } catch (HttpException e) {
            // 发生致命的异常，可能是协议不对或者返回的内容有问题
            System.out.println("Please check your provided http address!");
            e.printStackTrace();
        } catch (IOException e) {
            // 发生网络异常
            e.printStackTrace();
        } finally {
            // 释放连接
            postMethod.releaseConnection();
        }
    }
}