HttpServletRequest相关

短命女 2022-04-10 06:07 203阅读 0赞

简介

获取客户端请求头及参数

获取提交给服务器的中文数据

--------------------

# 简介 #

这个对象封装了客户端提交过来的一切数据。

# 获取客户端请求头及参数 #

package com.zhujunwei.httpServletRequest;
    
    import java.io.IOException;
    import java.util.Enumeration;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Set;
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class HttpServletRequest01 extends HttpServlet {
    	private static final long serialVersionUID = 1L;
    	
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		
    		//打印请求头
    		printRequestHeader(request);
    		System.out.println("-----------------------------");
    		//打印参数
    		printParameter(request);
    	}
    	
    	//打印请求体 get中url?号后面的内容
    	private void printParameter(HttpServletRequest request) {
    		Map<String, String[]> parameterMap = request.getParameterMap();
    		Set<String> paramKeySet = parameterMap.keySet();
    		Iterator<String> iterator = paramKeySet.iterator();
    		while(iterator.hasNext())
    		{
    			String key = iterator.next();
    			String value = parameterMap.get(key)[0];
    			System.out.println(key+"\t"+value);
    		}
    	}
    
    	//打印请求头
    	private void printRequestHeader(HttpServletRequest request) {
    		Enumeration<String> headerNames = request.getHeaderNames();
    		while(headerNames.hasMoreElements())
    		{
    			String name = headerNames.nextElement();
    			String value = request.getHeader(name);
    			System.out.println(name+"\t"+value);
    		}
    	}
    
    	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		doGet(request, response);
    	}
    
    }

比如在地址栏输入

http://localhost:8080/Hello/HttpServletRequest01?name=baobao&age=18

结果（FireFox）

host	localhost:8080
    user-agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0
    accept	text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
    accept-language	zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
    accept-encoding	gzip, deflate
    dnt	1
    connection	keep-alive
    upgrade-insecure-requests	1
    -----------------------------
    name	baobao
    age	18

# 获取提交给服务器的中文数据 #

<!DOCTYPE html>
    <html>
    <head>
    	<meta charset="UTF-8">
    	<title>Insert title here</title>
    </head>
    <body>
    	<h2>请输入账号密码登录</h2>
    	<form action="LoginServlet" method="post">
    		账号：<input type="text" name="username"><br>
    		密码：<input type="text" name="password"><br>
    		<input type="submit" value="登录">
    	</form>
    </body>
    </html>

LoginServlet

package com.zhujunwei.httpServletRequest;
    
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class LoginServlet extends HttpServlet {
    	private static final long serialVersionUID = 1L;
    
    	@Override
    	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
                  //getEncoding(req);
    		postEncoding(req);
    	}
    
    	// 取得用户名和密码
    	//解决post请求乱码
    	private void postEncoding(HttpServletRequest req) throws UnsupportedEncodingException {
    		req.setCharacterEncoding("UTF-8");
    		String username = req.getParameter("username");
    		String password = req.getParameter("password");
    		System.out.println("username=" + username);
    		System.out.println("password=" + password);
    	}
    
    	@SuppressWarnings("unused")
    	private void getEncoding(HttpServletRequest req) {
    		// 取得用户名和密码
    		String username = req.getParameter("username");
    		String password = req.getParameter("password");
    		System.out.println("username=" + username);
    		System.out.println("password=" + password);
    	}
    
    	@Override
    	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    		doGet(req, resp);
    	}
    }

我们可以提交给服务器中文用户名，依然可以接收到

![20181228000021687.png][]

username=宝宝
    password=123456

[20181228000021687.png]: /images/20220402/98bc96ba5175488086b9f34b65fa80fa.png