重定向与错误发送

重定向状态码

301、302

重定向demo

package com.test;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/first")
public class First extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // response.sendRedirect("https://www.baidu.com");
        response.sendRedirect("sencond"); // 重定向可以指定相对url，也可以指定绝对url
    }
}

package com.test;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/sencond")
public class Sencond extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.sendRedirect("https://www.sina.com.cn");
    }
}

---

发送错误

package com.test;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/first")
public class First extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //response.sendError(HttpServletResponse.SC_NOT_FOUND);
        response.sendError(HttpServletResponse.SC_NOT_FOUND, "笔记文件");
    }
}

response.sendError(HttpServletResponse.SC_NOT_FOUND)响应内容如下：

response.sendError(HttpServletResponse.SC_NOT_FOUND, "笔记文件")响应内容如下：