java 发送 接受 xml请求

二、客户端代码

通过Http Post Xml传递数据，客户端一般是通过URL建立到服务端的连接，向服务端发送xml数据，然后获取服务端的响应并进行解析：

String xmlString = "<?xml version='1.0' encoding='gb2312'?>"
                      + "<Req>"
                      + "<EventContentReq>"
                      + "<EventID>101</EventID >"
                      + "</EventContentReq>"
                      + "</Req>";

byte[] xmlData = xmlString.getBytes();

String urlStr = "http://124.128.62.164:7001/FetchTaskDataServlet";

DataInputStream input = null;

java.io.ByteArrayOutputStream out = null;

try{

       //获得到位置服务的链接

        URL url = new URL(urlStr);

        URLConnection urlCon = url.openConnection();

        urlCon.setDoOutput(true);

        urlCon.setDoInput(true);

        urlCon.setUseCaches(false);

       //将xml数据发送到位置服务

        urlCon.setRequestProperty("Content-Type", "text/xml");

        urlCon.setRequestProperty("Content-length",String.valueOf(xmlData.length));

        DataOutputStream printout = new DataOutputStream(urlCon.getOutputStream());

        printout.write(xmlData);

        printout.flush();

        printout.close();

        input = new DataInputStream(urlCon.getInputStream());

       byte[] rResult;

        out = new java.io.ByteArrayOutputStream();

       byte[] bufferByte = newbyte[256];

       int l = -1;

       int downloadSize = 0;

       while ((l = input.read(bufferByte)) > -1) {

            downloadSize += l;

            out.write(bufferByte, 0, l);

            out.flush();

        }

        rResult = out.toByteArray();

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        DocumentBuilder db = dbf.newDocumentBuilder();

        Document d = db.parse(new ByteArrayInputStream(rResult));

        String TaskAddr = d.getElementsByTagName("TaskAddr").item(0).getFirstChild().getNodeValue();

        System.out.println("TaskAddr:"+TaskAddr);

}

catch(Exception e){

        e.printStackTrace();

}

finally {

       try {

               out.close();

               input.close();

        }

       catch (Exception ex) {

        }

}
 三、服务端代码 服务端一般首先获取客户端发来的xml数据，进行解析，并将响应返回给客户端： try{

//解析对方发来的xml数据，获得EventID节点的值

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        DocumentBuilder db = dbf.newDocumentBuilder();

        Document d = db.parse(request.getInputStream());

        String evtid = d.getElementsByTagName("EventID").item(0).getFirstChild().getNodeValue();

//                    System.out.println("evtid" + evtid);

       //根据evtid查找任务，生成xml字符串

        UfgovDBUtil dbUtil = new UfgovDBUtil();

        String xmlString = dbUtil.fetchTaskData(evtid);

//                    System.out.println("returned xmlString:" + xmlString);

       //把xml字符串写入响应

       byte[] xmlData = xmlString.getBytes();

        response.setContentType("text/xml");

        response.setContentLength(xmlData.length);

        ServletOutputStream os = response.getOutputStream();

        os.write(xmlData);

        os.flush();

        os.close();

}

catch(Exception e){

        e.printStackTrace();

}