Mule ESB java组件两种写法

1是编写java的transformer， 2 是编写java的component 

先说1. 
说到底就是一个消息的转换功能， 就是获取到http请求过来的消息(payload), 然后将其转换为自己后续需要的格式的数据形态。 

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

 import javax.activation.DataHandler;

 import org.mule.api.MuleEventContext;
 import org.mule.api.MuleMessage;
 import org.mule.api.lifecycle.Callable;



 public class Transformer implements Callable  {

     @Override
     public Object onCall(MuleEventContext eventContext) throws Exception {
         // TODO Auto-generated method stub

         MuleMessage message  = eventContext.getMessage();

         //message.getPayload()得到的是通过Httpclient-MultipartEntity传过来的二进制流
         System.out.println(message.getPayload());
         InputStream in = (InputStream) message.getPayload();
         ByteArrayOutputStream bstream = new ByteArrayOutputStream();
         byte[] buff = new byte[100];
         int rc = 0;
         try {
             while ((rc = in.read(buff, 0, 100)) > 0) {
                 bstream.write(buff, 0, rc);
             }
         } catch (IOException e) {
             e.printStackTrace();
         }
         byte[] bytes = bstream.toByteArray();

         System.out.println("-------------------------111--" + bytes);
         //httpClient addPart传过来的StringBody
         System.out.println(message.getInboundAttachmentNames());
         DataHandler h1 = message.getInboundAttachment("serviceId");
         DataHandler h2 =  message.getInboundAttachment("fileName");
         System.out.println("------------------------------------");

         Map map = new HashMap();
         map.put("serviceId", h1.getContent().toString());
         map.put("fileName", h2.getContent().toString());
         map.put("payload", bytes);

         return map;
     }
 }

将http post过来的两个字符串参数 和 一个文件byte流 转换为 map形式， 目的是因为http传过来的是 multipart/form-data ， 而后面的框架代码要同时兼容application/x-www-form-urlencoded , 所以统一进行转换 

实现Callable 接口， 取得MuleEventContext上下文，进而获取MuleMessage。 
其中getPayload()得到了 inputstream ， 获取文件字节数组， 通过getInboundAttachment("serviceId") 获取到StringBody、 
直接返回消息实例 


2. component 
目的是改变消息set到MuleEvent ，返回event 

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

 import javax.activation.DataHandler;

 import org.mule.api.MuleEvent;
 import org.mule.api.MuleException;
 import org.mule.api.MuleMessage;
 import org.mule.api.processor.MessageProcessor;

 public class MutipartTransformer implements MessageProcessor  {

     @Override
     public MuleEvent process(MuleEvent event) throws MuleException {

         MuleMessage mulemessage = event.getMessage();

         InputStream in = (InputStream) mulemessage.getPayload();
         ByteArrayOutputStream bstream = new ByteArrayOutputStream();
         byte[] buff = new byte[100];
         int rc = 0;
         try {
             while ((rc = in.read(buff, 0, 100)) > 0) {
                 bstream.write(buff, 0, rc);
             }
         } catch (IOException e) {
             e.printStackTrace();
         }
         byte[] bytes = bstream.toByteArray();


         System.out.println(mulemessage.getInboundAttachmentNames());
         DataHandler h1 = mulemessage.getInboundAttachment("serviceId");
         DataHandler h2 =  mulemessage.getInboundAttachment("fileName");
         try {
             System.out.println(h1.getContent().toString());
         } catch (IOException e) {
             e.printStackTrace();
         }
         try {
             System.out.println(h2.getContent().toString());
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         System.out.println("bbbbbbbbbbbbbbbbbbbbbbbbb    ");

         Map map = new HashMap();
         map.put("serviceId", h1);
         map.put("fileName", h2);
         map.put("payload", bytes);
         event.setMessage(mulemessage);
         return event;
     }
 }