Android与JavaWeb通过HTTP通信

╰+攻爆jí腚メ 2022-05-22 04:36 195阅读 0赞

# 一、get方式通信 #

## 1、Web端 ##

**1）建立一个Servlet命名为TestAppServlet**

import java.io.IOException;
    import javax.servlet.ServletException;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    
    @WebServlet("/TestAppServlet")
    public class TestAppServlet extends HttpServlet { 
    
        /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */
        protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            System.out.println("接收到客户端的访问：");
            System.out.println(request.getParameter("param"));
            response.getOutputStream().print("Server data");
        }
    
        /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            doGet(request, response);
        }
    
    }

**2）在webContent/WEB-INF/web.xml文件中注册TestAppServlet**

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
      <servlet>
        <servlet-name>TestAppServlet</servlet-name>
        <servlet-class>com.zcn.servlet.TestAppServlet</servlet-class>
      </servlet>
      <servlet-mapping>
        <servlet-name>TestAppServlet</servlet-name>
        <url-pattern>/servlet/TestAppServlet</url-pattern>
      </servlet-mapping>
    </web-app>

## 2、Android端 ##

# 二、post方式通信 #

## 1、web端不变 ##

## 2、Android端 ##

public class MainActivity extends AppCompatActivity { 
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            Thread thread = new Thread(){
                @Override
                public void run() {
                    //initView();
                    doPost();
                }
            };
            thread.start();
    
        }
    
        private void doPost(){
            String strUrl="http://192.168.2.169:8080/TestTomcat/servlet/TestAppServlet";//地址要写成跑web程序端的地址，且如果web端不是在服务器上还要保证手机端和web端在同一局域网下
            URL url = null;
            try {
                url=new URL(strUrl);
                HttpURLConnection urlConn = (HttpURLConnection)url.openConnection();
                urlConn.setDoInput(true);//设置输入流采用字节流
                urlConn.setDoOutput(true);//设置输出流采用字节流
                urlConn.setRequestMethod("POST");//设置以post形式
                urlConn.setUseCaches(false);//设置缓存
                urlConn.setRequestProperty("Content_Type", "application/x-www-form-urlencoded");//设置meta参数
                urlConn.addRequestProperty("Charset", "utf-8");//设置编码格式为utf-8
                System.out.println("Chunna==开始连接");
                urlConn.connect();
    
                //发送数据
                DataOutputStream dos = new DataOutputStream(urlConn.getOutputStream());
                dos.writeBytes("param="+ URLEncoder.encode("hello", "utf-8"));
                dos.flush();
                dos.close();
    
                //接收数据
                BufferedReader br = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));
                String result = "";
                String readLine=null;
                while((readLine=br.readLine())!=null){
                    System.out.println("Chunna==不为空");
                    result+=readLine;
                }
                br.close();
                urlConn.disconnect();
                System.out.println("Chunna==结果"+result);
            }catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }