HTTP

1.服务端使用的是web容器（tomcat），提供一个servlet，配置到web.xml中，这样服务端就有了一个服务类了。配置如下：

<servlet>
    <display-name>ApplicationServiceServlet</display-name>
    <servlet-name>ApplicationServiceServlet</servlet-name>
    <servlet-class>com.lsz.servlet.ApplicationServiceServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  	<servlet-name>ApplicationServiceServlet</servlet-name>
  	<url-pattern>/ApplicationServiceServlet</url-pattern>
  </servlet-mapping>

2.客户端代码如下：

public static void main(String[] args) {
		try{
			URL url = new URL("http://localhost:8080/serverend/ApplicationServiceServlet");
			HttpURLConnection conn = (HttpURLConnection)url.openConnection();
			conn.setRequestMethod("POST");
			conn.setDoInput(true);
			conn.setDoOutput(true);
			conn.setUseCaches(false);
			conn.connect();
			// 设置请求参数
			DataOutputStream doutput = new DataOutputStream(conn.getOutputStream());
			String requestParameter = "action=get_current_data";
			doutput.writeBytes(requestParameter);
			doutput.flush();
			doutput.close();
			int code = conn.getResponseCode();
			if(code == HttpURLConnection.HTTP_OK){
				System.out.println(readMessage(conn.getInputStream()));
			}
			else{
				System.out.println("Request failed,check the URL ["+conn.getURL()+"] please!");
			}
                            conn.disconnect();
		}
		catch(Exception ex){
			ex.printStackTrace();
		}
	}
	public static String readMessage(InputStream input)throws Exception{
		ByteArrayOutputStream output = new ByteArrayOutputStream(4*1024);
		byte[] bit = new byte[1024];
		int count = 0;
		while((count = input.read(bit))>0){
			output.write(bit, 0, count);
		}
		input.close();
		return new String(output.toByteArray());
	}