JavaWeb应用HttpServletRequest获得前端传递的参数以及请求转发（页面跳转）

HttpServletRequest代表客户端的请求，用户通过Http协议访问服务器，HTTP请求中的所有信息会被封装到HttpServletRequest，通过这个HttpServletRequest的方法，获得客户端的所有信息；

LoginServlet类

public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        req.setCharacterEncoding("utf-8");//后台接收中文乱码问题
        resp.setCharacterEncoding("utf-8");

        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String[] numbers = req.getParameterValues("number");

        System.out.println("=================================");
        
        System.out.println(username);
        System.out.println(password);
        System.out.println(Arrays.toString(numbers));
        System.out.println("=================================");

        //通过请求转发
        //这里的 / 代表当前的web应用
        req.getRequestDispatcher("/success.jsp").forward(req, resp);

    }

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

web.xml

<servlet>
    <servlet-name>LoginServlet</servlet-name>
    <servlet-class>com.ping.servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>LoginServlet</servlet-name>
    <url-pattern>/login</url-pattern>
</servlet-mapping>

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登录</title>
</head>
<body>
<h1>登录</h1>
<div>
    <%--这里表单的意思：以post方式提交表单，提交到login请求--%>
    <form action="${pageContext.request.contextPath}/login" method="post">
        用户名：<input type="text" name="username"><br>
        密码：<input type="password" name="password"><br>
        数字：
        <input type="checkbox" name="number" value="一">一
        <input type="checkbox" name="number" value="二">二
        <input type="checkbox" name="number" value="三">三
        <input type="checkbox" name="number" value="四">四
        <br>
        <input type="submit">
    </form>
</div>

</body>
</html>

新建success.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>登录成功</h1>

</body>
</html>

测试结果
- 首页输入信息
- 点击提交转发到：http://localhost:8080/r/login
- 控制台输出信息

原文链接：https://blog.csdn.net/qq_45974648/article/details/119968768