Request_获取请求参数中文乱码问题处理以及请求转发

Request_获取请求参数中文乱码问题处理

中文乱码问题：

　　get方式：tomcat 8 已经将get方式乱码问题解决了

　　post方式：会乱码

　　　　解决：在获取参数前，设置request的编码：request.setCharacterEncoding("utf-8");

@WebServlet(name = "RequestDemo7", value = "/RequestDemo7")
public class RequestDemo7 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //设置编码
        request.setCharacterEncoding("utf-8");

//        post获取请求参数
        String username = request.getParameter("username");

        System.out.println(username);
    }
}

Request_请求转发

请求转发：一种在服务器内部的资源跳转方式

　　1.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);

demo8

@WebServlet(name = "RequestDemo8", value = "/RequestDemo8")
public class RequestDemo8 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("demo8....被访问了");
        //转发到demo9资源
        /*RequestDispatcher requestDispatcher = request.getRequestDispatcher("/RequestDemo9");
        requestDispatcher.forward(request, response);*/
        //链式编程
        request.getRequestDispatcher("/RequestDemo9").forward(request, response);
    }
}

demo9

@WebServlet(name = "RequestDemo9", value = "/RequestDemo9")
public class RequestDemo9 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("demo9....也被访问了");
    }
}

特点：

　1、浏览器地址栏路径不会发生变化　　

　　2、只能转发到当前服务器内部资源中

　　3、转发是一次请求