Request获取请求参数中文乱码问题处理和请求转发

Request获取请求参数中文乱码问题处理

中文乱码问题：

　　get方式：tomcat8已经将get方式乱码问题解决了

<body>
    <form action="/requestDemo3" method="get">
        <input type="text" placeholder="请输入用户名" name="username"><br>
        <input type="text" placeholder="请输入密码" name="password"><br>

        <input type="checkbox" name="hobby" value="game">游戏
        <input type="checkbox" name="hobby" value="study">学习
        <br>
        <input type="submit" value="注册">
    </form>
</body>

@WebServlet("/requestDemo3")
public class RequestDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //post获取请求参数
        String username = request.getParameter("username");
        System.out.println(username);

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

　　post方式：会乱码

<body>
    <form action="/requestDemo3" method="post">
        <input type="text" placeholder="请输入用户名" name="username"><br>
        <input type="text" placeholder="请输入密码" name="password"><br>

        <input type="checkbox" name="hobby" value="game">游戏
        <input type="checkbox" name="hobby" value="study">学习
        <br>
        <input type="submit" value="注册">
    </form>
</body>

　　　　解决：在请求参数前，设置request的编码

@WebServlet("/requestDemo3")
public class RequestDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //post获取请求参数
        request.setCharacterEncoding("UTF-8");
        String username = request.getParameter("username");
        System.out.println(username);

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

Request请求转发

请求转发：一种在服务器内部的资源跳转方式

步骤：

　　1、通过request对象获取请求转发器对象

　　　　　RequestDispatcher getRequestDispatcher(String path);

　　2、使用RequestDispatcher对象来进行转发

　　　　forward(ServletRequest request,Response response);

@WebServlet("/requestDemo3")
public class RequestDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("requestDemo3.....");
        request.getRequestDispatcher("/requestDemo4").forward(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

@WebServlet("/requestDemo4")
public class RequestDemo4 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("requestDemo4.....");
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}