获取请求数据 - 获取表单数据 - 《JAVA学习》

根据key获取指定value
req.getParameter(“key”);
根据key获取对应的value，返回一个字符串。
String str=req.getParameter(“key”);

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>添加用户</title>
</head>
<body>
    <form action="getRequestDataServlet.do" method="post">
        <input type="text" name="username"/><br/>
        <input type="password" name="userpwd"/><br/>
        <input type="submit" value="OK"/>
    </form>
</body>
</html>

package com.itbaizhan;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
/**
 * 获取请求数据
 */
public class GetRequestDataServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取用户名
        String username = req.getParameter("username");
        //获取用户密码
        String pwd = req.getParameter("userpwd");
        PrintWriter printWriter = resp.getWriter();
        printWriter.println(username);
        printWriter.println(pwd);
        printWriter.flush();
        printWriter.close();
    }
}

    <servlet>
        <servlet-name>getRequestDataServlet</servlet-name>
        <servlet-class>com.itbaizhan.GetRequestDataServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>getRequestDataServlet</servlet-name>
        <url-pattern>/getRequestDataServlet.do</url-pattern>
    </servlet-mapping>