javaweb开发（五）：HttpServletRequest与HttpServletResponse详解

构建1个web项目，导入依赖
查看HttpServlet类
下载源码包，下载链接
解压并导入
新建RequsetServlet

@WebServlet("/request")
public class RequsetServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse resp) throws ServletException, IOException {
        //客户端请求信息
        System.out.println("应用上下文路径 getContextPath="+request.getContextPath()) ;
        System.out.println("客户端发出请求时的完整URL getRequestURL="+request.getRequestURL()) ;
        System.out.println("请求行中的资源名部分 getRequestURI="+request.getRequestURI()) ;
        System.out.println("请求行中的参数部分 getQueryString="+request.getQueryString()) ;
        System.out.println("发出请求的客户机的IP地址 getRemoteAddr="+request.getRemoteAddr()) ;
        System.out.println("客户机发请求使用的网络端口号 getRemotePort="+request.getRemotePort()) ;
        //获取请求头
        System.out.println("获取请求头 getHeader(Accept)="+request.getHeader("Accept")) ;
        //获取请求参数
        System.out.println("客户端请求参数 getParameter="+request.getParameter("userName"));
        String[] sport = request.getParameterValues("sport");
        System.out.println("客户端请求参数列表,多个值 getParameterValues="+sport.toString());
        Map<String,String[]> map = request.getParameterMap();
        System.out.println("客户端请求参数封装成的map类型 getParameterMap="+map.toString());
        //存储到reqeust作用域
        request.setAttribute("name","jack");
    }

}

tomcat配置如下
测试

http://127.0.0.1:8080/web03/request?userName=jack&age=11&sport=ball&sport=sleep

控制台输出如下

12-Apr-2022 22:15:39.484 淇℃伅 [Catalina-utility-1] org.apache.catalina.startup.HostConfig.deployDirectory 鎶妛eb 搴旂敤绋嬪簭閮ㄧ讲鍒扮洰褰� [C:\Program Files\Apache Software Foundation\Tomcat 10.0\webapps\manager]
12-Apr-2022 22:15:39.531 淇℃伅 [Catalina-utility-1] org.apache.catalina.startup.HostConfig.deployDirectory Web搴旂敤绋嬪簭鐩綍[C:\Program Files\Apache Software Foundation\Tomcat 10.0\webapps\manager]鐨勯儴缃插凡鍦╗47]姣鍐呭畬鎴�
应用上下文路径 getContextPath=/web03
客户端发出请求时的完整URL getRequestURL=http://127.0.0.1:8080/web03/request
请求行中的资源名部分 getRequestURI=/web03/request
请求行中的参数部分 getQueryString=userName=jack&age=11&sport=ball&sport=sleep
发出请求的客户机的IP地址 getRemoteAddr=127.0.0.1
客户机发请求使用的网络端口号 getRemotePort=54357
获取请求头 getHeader(Accept)=text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
客户端请求参数 getParameter=jack
客户端请求参数列表,多个值 getParameterValues=[Ljava.lang.String;@345e0725
客户端请求参数封装成的map类型 getParameterMap=org.apache.catalina.util.ParameterMap@6b83c953

实现登录提交
新建LoginServlet

@WebServlet(name = "loginServlet",urlPatterns = {"/user/loin"})
public class LoginServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html;charset=utf-8");
        String userName = req.getParameter("userName");
        String pwd = req.getParameter("pwd");
        if(userName.equals("user") && pwd.equals("12345")){
            resp.getWriter().write("登录成功");
        }else {
            resp.getWriter().write("账号密码错误");
        }
    }

}

编写index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>login</title>
  </head>
  <body>
    <form action="/web03/user/loin" method="post">
      <div>用户名: <input type="text" name="userName" /> </div>
      <div>密码: <input type="password" name="pwd"/> </div>
      <div> <input type="submit"  value="登录"> </div>
    </form>
  </body>
</html>

启动测试
解决乱码

//POST⽅式遇到中⽂乱码，如果客户端是以UTF-8字符编码，需要服务器以UTF-8的编码接收数据，
req.setCharacterEncoding("UTF-8");
//对于以get⽅式传输的中⽂数据乱码需要另外⼀种⽅式，默认的还是使⽤ISO8859-1这个字符编码来接
收数据
//办法：对接收到的原始数据的字节数组，然后通过字节数组以指定的编码构建字符串，解决乱码问题
String name = request.getParameter("name");//接收数据
name =new String(name.getBytes("ISO8859-1"), "UTF-8")

HttpServletResponse响应对象讲解
编写ResponseServlet

@WebServlet("/response")
public class ResponseServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse response) throws ServletException, IOException {
        // 设置编码
        response.setCharacterEncoding("UTF-8");
         response.addHeader("name", "java");
         response.addHeader("name", "spring");
    }

}

测试
设置只有⼀个值的http响应头,参数name表示响应头名称,参数value表示响应头的值

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");
        response.setHeader("age","23");
    }

设置状态码

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");
        response.setStatus(200);
    }

字节输出流对象

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");
        response.setHeader("Content-Type","text/html;charset=utf-8");
        String data = "hello world";
        OutputStream outputStream = response.getOutputStream();
        byte[] bytes = data.getBytes("UTF-8");
        outputStream.write(bytes);
    }

字符输出流对象

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");
        response.setHeader("Content-Type","text/html;charset=utf-8");
        String data = "hello world";
        PrintWriter printWriter = response.getWriter();
        printWriter.write(data);
    }

posted @ 2022-04-12 22:03 DogLeftover 阅读(73) 评论(0) 编辑收藏举报

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