springmvc转发外部url

转载

mob64ca1406d617 2024-11-17 08:31:50

文章标签 springmvc转发外部url java spring System html 文章分类 架构后端开发

SpringMVC
MVC
m：model:模型，javabean
v：view：视图，html/jsp
c：controller：控制器：servlet
MyMVC模拟实现

⼀. 阶段⼀

index.html⻚⾯

<!DOCTYPE html>
<html lang="en"> <head>
 <meta charset="UTF-8">
 <title>index</title>
</head> <body>
 <h1>this is index page.</h1>
 <form method="post" action="ProductServlet">
 pid:<input type="text" name="pid" /><br />
 pname:<input type="text" name="pname" /><br />
 price:<input type="text" name="price" /><br />
 img:<input type="text" name="img" /><br />
 <input type="submit" value="submit" /><br />
 </form>
</body>
</html>

ProductServlet.java

package com.qfedu.controller;
import com.qfedu.bean.Product;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@javax.servlet.annotation.WebServlet(urlPatterns = "/ProductServlet")
public class ProductServlet extends HttpServlet {
 protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
 //System.out.println(123);
 String pid = request.getParameter("pid");
 String pname = request.getParameter("pname");
 String sprice = request.getParameter("price");
 String img = request.getParameter("img");
 double price = sprice == null ? 0.0 :
Double.parseDouble(sprice);
 System.out.println("pid : " + pid);
 System.out.println("price : " + sprice);
 System.out.println("pname : " + pname);
 System.out.println("img : " + img);
 Product p = new Product();
 p.setPid(pid);
 p.setPname(pname);
 p.setImg(img);
 p.setPrice(price);
 request.setAttribute("p", p);
 
request.getRequestDispatcher("product.jsp").forward(request,response);
 }
 protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
 doPost(request, response);
 }
}

Product.jsp

可以实现⻚⾯的跳转以及数据的展示
问题：⻚⾯都在webapp下，安全性不⾼

<%--
  Created by IntelliJ IDEA.
  User: james
  Date: 2020/3/2
  Time: 2:52 PM
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>product</title>
</head>
<body>
    <h1>this is product detail page.</h1>

    <%--
        ognl: 对象导航语言
            user.addr.province;
    --%>
    <h3>pid : ${p.pid}</h3>
    <h3>pname : ${p.pname}</h3>
    <h3>price : ${p.price}</h3>
    <h3>img : ${p.img}</h3>
</body>
</html>

⼆.阶段⼆

为了提⾼程序的安全性，将所有的⻚⾯都放⼊webapp/WEB-INF/view⽬录下，index.html⻚⾯⽆法
直接访问，需要专⻔建⽴⼀个Sevlet来访问该⻚⾯，实现内容请求转发
新建⼀个Servlet来实现内部转发 ProductInputServlet.java

package com.qfedu.controller;

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(urlPatterns = "/ProductInputServlet")
public class ProductInputServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.getRequestDispatcher("/WEB-INF/view/index.html").forward(request, response);
    }

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

webapp下的WEB-INF/view/index.html⻚⾯可以直接访问，更新ProductServlet.java

package com.qfedu.controller;
import com.qfedu.bean.Product;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@javax.servlet.annotation.WebServlet(urlPatterns = "/ProductServlet")
public class ProductServlet extends HttpServlet {
 protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
 //System.out.println(123);
 String pid = request.getParameter("pid");
 String pname = request.getParameter("pname");
 String sprice = request.getParameter("price");
 String img = request.getParameter("img");
 double price = sprice == null ? 0.0 :
Double.parseDouble(sprice);

三. 阶段三，模拟Spring MVC的具体实现

Controller.java

package com.qfedu.mvc.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 自定义接口，实现管理多个请求,在模拟Spring MVC中的控制器
 */
public interface Controller {

    String handleRequest(HttpServletRequest request, HttpServletResponse response);
}

2.ProductInputController.java

package com.qfedu.mvc.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ProductInputController implements Controller {
    @Override
    public String handleRequest(HttpServletRequest request, HttpServletResponse response) {
        return "/WEB-INF/view/index.html";
    }
}

3.ProductDetailController.java

package com.qfedu.mvc.controller;

import com.qfedu.bean.Product;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ProductDetailController implements Controller {
    @Override
    public String handleRequest(HttpServletRequest request, HttpServletResponse response) {

        String pid = request.getParameter("pid");
        String pname = request.getParameter("pname");
        String sprice = request.getParameter("price");
        String img = request.getParameter("img");

        double price = sprice == null ? 0.0 : Double.parseDouble(sprice);

        System.out.println("pid : " + pid);
        System.out.println("price : " + sprice);
        System.out.println("pname : " + pname);
        System.out.println("img : " + img);

        Product p = new Product();

        p.setPid(pid);
        p.setPname(pname);
        p.setImg(img);
        p.setPrice(price);

        request.setAttribute("p", p);

        return "/WEB-INF/view/product.jsp";
    }
}

4.DispatcherServlet.java负责将多个请求分发给各自不同的控制器

package com.qfedu.mvc.controller;

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(urlPatterns = {"/ProductInput", "/ProductDetail"})
public class DispatcherServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String requestURI = request.getRequestURI();
        //System.out.println(requestURI);

        String action = requestURI.substring(requestURI.lastIndexOf("/") + 1);

        //System.out.println(action);

        Controller controller = null;

        if("ProductInput".equalsIgnoreCase(action)){
            controller = new ProductInputController();
        }else if("ProductDetail".equalsIgnoreCase(action)){
            controller = new ProductDetailController();
        }

        String url = controller.handleRequest(request, response);

        request.getRequestDispatcher(url).forward(request, response);
    }

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

结论：多个请求可以交给同一个Servlet（DispatcherServlet），然后各自不同的请求会交给各自的控制器。所有请求都叫个DispatcerServet，该角色相当于一个前端控制器，可以大大的提高客户的以及服务器端的工作效率

四.阶段四

给阶段三的功能之上添加一个校验功能

新增一个ProductForm.java,主要用来做Product校验，struts1有专门的formbean对象用来校验表单数据，在某些框架中将formbean与bean对象合二为一了

package com.qfedu.form;

public class ProductForm {

    private String pname;
    private double price;
    private String img;

    public String getPname() {
        return pname;
    }

    public void setPname(String pname) {
        this.pname = pname;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getImg() {
        return img;
    }

    public void setImg(String img) {
        this.img = img;
    }
}

ProductValidate.java，用来完成对于formbean进行校验，如果校验不通过，则将错误信息存储起来

package com.qfedu.validate;

import com.qfedu.form.ProductForm;

import java.util.ArrayList;
import java.util.List;

public class ProductValidate {

    /**
     * 校验给定的ProductForm对象
     * @param pf 要校验的对象
     * @return 表单校验不成功，则将错误信息存储
     */
    public List<String> validate(ProductForm pf){
        List<String> errors = null;

        String pname = pf.getPname();
        String img = pf.getImg();
        double price = pf.getPrice();

        errors = new ArrayList<>();

        if(pname == null || pname.length() == 0){
            errors.add("product name must not be empty.");
        }


        if(img == null || img.length() == 0){
            errors.add("product image must not be empty.");
        }

        if(price < 0){
            errors.add("the price of product must be a positive number.");
        }

        return errors;
    }
}

更新ProductDetailController.java

package com.qfedu.mvc.controller;

import com.qfedu.ProductValidate;
import com.qfedu.bean.Product;
import com.qfedu.form.ProductForm;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

public class ProductDetailController implements Controller {
    @Override
    public String handleRequest(HttpServletRequest request, HttpServletResponse response) {

        String pid = request.getParameter("pid");
        String pname = request.getParameter("pname");
        String sprice = request.getParameter("price");
        String img = request.getParameter("img");

        double price = sprice == null ? 0.0 : Double.parseDouble(sprice);

        System.out.println("pid : " + pid);
        System.out.println("price : " + sprice);
        System.out.println("pname : " + pname);
        System.out.println("img : " + img);

        ProductForm pf = new ProductForm();

        pf.setImg(img);
        pf.setPname(pname);
        pf.setPrice(price);

        ProductValidate pv = new ProductValidate();

        List<String> errors = pv.validate(pf);

        try {
            if(errors != null && !errors.isEmpty()){
                request.setAttribute("errors", errors);
                return "/WEB-INF/view/index.jsp";
            }else{

                Product p = new Product();

                p.setPid(pid);
                p.setPname(pf.getPname());
                p.setImg(pf.getImg());
                p.setPrice(pf.getPrice());

                request.setAttribute("p", p);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return "/WEB-INF/view/product.jsp";
    }
}

index.jsp文件

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>product</title>

    <!-- 引入 Bootstrap -->
    <link href="https://cdn.bootcss.com/twitter-bootstrap/3.3.7/css/bootstrap-theme.css" rel="stylesheet">
    <link href="https://cdn.bootcss.com/twitter-bootstrap/3.3.7/css/bootstrap.css" rel="stylesheet">
</head>
<body>
<h1>this is product  inner index jsp page</h1>
<c:if test="${errors!=null}">
    <ul>
        <c:forEach items="${errors}" var="e">
            <li><font color="red">${e}</font> </li>
        </c:forEach>
    </ul>
</c:if>
<!--<form method="post" action="/ProductServlet">-->
<form role="form" method="post" action="/ProductDetail">
<div class="form-group">
    pid:<input type="text" class="form-control" name="pid" placeholder="请输入编号"><br>
    pname:<input type="text" class="form-control" name="pname" placeholder="请输入用户名"><br>
    price:<input type="text" class="form-control" name="price" placeholder="请输入价格"><br>
    img:<input type="text" class="form-control" name="img" placeholder="请输入上传格式正确的图片"><br>
    <input type="submit" value="submit"><br>
</div>

</form>
<script src="https://code.jquery.com/jquery.js"></script>
<!-- 包括所有已编译的插件 -->
<script src="https://cdn.bootcss.com/twitter-bootstrap/3.3.7/js/bootstrap.js"></script>
</body>
</html>