创建属于自己的第一个接口

右键src下的包名-》new -》servlet 创建一个HelloServlet.java

HelloServlet.java

package com.yxj.testweb1;

import java.io.IOException;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.google.gson.Gson;


/**
 * Servlet implementation class HelloServlet
 */
@WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {
	
	
	private static final long serialVersionUID = 1L;
       
	/**
	 * Servlet 生命周期可被定义为从创建直到毁灭的整个过程。以下是 Servlet 遵循的过程：
       Servlet 通过调用 init () 方法进行初始化。
       Servlet 调用 service() 方法来处理客户端的请求。
       Servlet 通过调用 destroy() 方法终止（结束）。
       最后，Servlet 是由 JVM 的垃圾回收器进行垃圾回收的。
	 * 
	 */
	
	@Override
	public void init() throws ServletException {
		// TODO Auto-generated method stub
		super.init();
		System.out.println("测试init");
	}
	
	
	
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		super.service(req, resp);
		System.out.println("测试service");
	}
	
	
	
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		super.destroy();
	}
	
	
    /**
     * @see HttpServlet#HttpServlet()
     */
    public HelloServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    
	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		// 设置响应内容类型
        response.setContentType("text/html;charset=UTF-8");
        response.setCharacterEncoding("GBK");
		String name = request.getParameter("name");
		
		 
		Enumeration<String> msg = request.getParameterNames();
		//所有请求参数都是以字符串数组获取
		Map<String, String[]> map = request.getParameterMap();
		//获取指定字段参数值  以数组形式获取
		String[] a = request.getParameterValues("name");
		
		System.out.println(new Date()+"--->"+new Gson().toJson(map));
		System.out.println(new Date()+"--->"+new Gson().toJson(a));
		System.out.println(new Date()+"--->"+new Gson().toJson(msg));
		
		
		if(name!=null&&name.equals("yangxiaojiang")) {
			
			HashMap<String, Object> hashMap = new HashMap<String, Object>();
			hashMap.put("Data", new ClassBean("java","开发语言"));
			hashMap.put("msg", "登录成功！");
			
			String dataResultString = new Gson().toJson(hashMap);
			// 使用 GBK 设置中文正常显示
	        response.getWriter().write(dataResultString);
	        System.out.println(new Date()+"--->"+dataResultString);
		}else {
			// 使用 GBK 设置中文正常显示
			response.setCharacterEncoding("GBK");
	        response.getWriter().write(new Date()+"--->"+"请输入正确的名字！");
	        System.out.println(new Date()+"--->"+"请输入正确的名字！");
		}
		
		
		//请求完了销毁
		destroy();
	}

	
	
	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}
}

然后我们在 web.xml 文件中创建以下条目：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns="http://xmlns.jcp.org/xml/ns/javaee" 
 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  
  
  <servlet>  
     <!-- 类名 -->  
    <servlet-name>HelloServlet</servlet-name>  
    <!-- 所在的包 -->  
    <servlet-class>com.yxj.testweb1.HelloServlet</servlet-class>  
  </servlet>  
  
  
  <servlet-mapping>  
    <servlet-name>HelloServlet</servlet-name>  
    <!-- 访问的网址 -->  
    <url-pattern>/WebApp/HelloServlet</url-pattern>  
    </servlet-mapping>  
  
</web-app>

使用get请求
接口地址：http://localhost:8080/TestWeb1/WebApp/HelloServlet?name=yangxiaojiang&name=yangxiaoj&sex=0

服务器端获取上传参数log信息