Java应用程序与Web服务器交互

╰半橙微兮° 2022-06-18 10:59 203阅读 0赞

1、服务端的代码如下(需要javax.servlet.jar)：

package com.lanp.servlet;
    
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class HandlerHttpRequestServlet extends HttpServlet {
    	private static final long serialVersionUID = 1L;
    
    	@Override
    	protected void doGet(HttpServletRequest arg0, HttpServletResponse arg1)throws ServletException, IOException {
    		super.doGet(arg0, arg1);
    	}
    
    	@Override
    	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
    			throws ServletException, IOException {
    		String username =req.getParameter("username");          //获取username所对应的value
            String password =req.getParameter("password");           //获取password所对应的value
            System.out.println("The received username and password is: " + username + "/" +password);
            
            // 向请求端发回反馈信息
            PrintWriter out =resp.getWriter();
            out.print("OK");
            out.flush();
            out.close();
            
            super.doPost(req, resp);
    	}
    }

2、在Tomcat的webapps文件夹下新建一个JavaApp的文件夹，在JavaApp下新建一个WEB-INF文件夹，在WEB-INF下新建lib文件夹和classes文件夹，在WEB-INF下新建一个web.xml文件。

3、lib文件夹下放commons-logging-1.0.4.jar和commons-logging-1.0.4.jar。

4、classes文件夹下放HandlerHttpRequestServlet.class文件。

5、web.xml文件的内容如下：

<?xml version="1.0" encoding="UTF-8"?>
    <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    	<display-name>JavaApp</display-name>
    	
    	 <servlet>
             <servlet-name>JavaAppAervletUpLoad</servlet-name>
              <servlet-class>com.lanp.servlet.HandlerHttpRequestServlet</servlet-class>
        </servlet>
     
        <servlet-mapping>   
             <servlet-name>JavaAppAervletUpLoad</servlet-name>
             <url-pattern>/upload</url-pattern>  
        </servlet-mapping>
    	
    	
    	<welcome-file-list>
    		<welcome-file>index.html</welcome-file>
    		<welcome-file>index.htm</welcome-file>
    		<welcome-file>index.jsp</welcome-file>
    		<welcome-file>default.html</welcome-file>
    		<welcome-file>default.htm</welcome-file>
    		<welcome-file>default.jsp</welcome-file>
    	</welcome-file-list>
    </web-app>

6、Java应用程序代码如下：

package com.lanp;
    
    import java.io.BufferedReader;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStreamWriter;
    import java.net.HttpURLConnection;
    import java.net.URL;
    
    /**
     * Java应用程序
     * @author LanP
     * @since 2011-11-1 22:36
     * @version V1.0
     */
    public class JavaApp {
    
    	public static void main(String[] args) throws Exception {
    		// 服务地址
            URL url = new URL("http://127.0.0.1:8080/JavaApp/upload");
    
            // 设定连接的相关参数
            HttpURLConnection connection= (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setRequestMethod("POST");
            OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream(), "UTF-8");
            
            // 向服务端发送key = value对
            out.write("username=lanp&password=lanpiao");
            out.flush();
            out.close();
            
            // 获取服务端的反馈
            String strLine="";
            String strResponse ="";
            InputStream in =connection.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            while((strLine =reader.readLine()) != null)
            {
                     strResponse +=strLine +"\n";
            }
            System.out.print(strResponse);
    	}
    
    }

7、先启动Tomcat后运行JavaApp。

OK，TKS！