java - 如何将跨源资源共享与 Spring MVC 4.0.0 RESTful Webservice 集成

Question

我有一个返回 JSON 数据的简单 Web 服务。

User Class (com.bargadss.SpringService.Domain) 是 POJO 类包含

user_ID, firstName, lastName, eMail

UserService类(com.bargadss.SpringService.DAO)的两大操作

1. getAllUser() -> Queries the DB to Select all Users from User Table and returns List{User}
2. getUserById(int user_ID) -> Queries the DB to Select a specific user based on ID

SpringServiceController (com.bargadss.SpringService.Controller) 如下:

package com.bargadss.SpringService.Controller;

import java.util.List;

import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.bargadss.SpringService.DAO.UserService;
import com.bargadss.SpringService.Domain.User;


@RestController
@RequestMapping("/service/user/")
public class SpringServiceController {
 UserService userService=new UserService();

 @RequestMapping(value = "/{id}", method = RequestMethod.GET,headers="Accept=application/json")
 public User getUser(@PathVariable int id) {        
  User user=userService.getUserById(id);
  return user;
 }

 @RequestMapping(method = RequestMethod.GET,headers="Accept=application/json")
 public List<User> getAllUsers() {   
  List<User> users=userService.getAllUsers();
  return users;
 }
}

ListUserController (com.bargadss.SpringService.Controller) 如下:

package com.bargadss.SpringService.Controller;

import java.util.LinkedHashMap;
import java.util.List;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.servlet.ModelAndView;

import com.bargadss.SpringService.Domain.User;


@Controller
public class ListUserController {

@RequestMapping("/listUsers")
public ModelAndView listUsers() { 
    RestTemplate restTemplate = new RestTemplate();
    String url="http://localhost:8080/SpringServiceWithRESTAndJSONExample/service/user/";    
    List<LinkedHashMap> users=restTemplate.getForObject(url, List.class);
    return new ModelAndView("listUsers", "users", users);
}

@RequestMapping("/dispUser/{userid}")
public ModelAndView dispUser(@PathVariable("userid") int userid) { 
    RestTemplate restTemplate = new RestTemplate();
    String url="http://localhost:8080/SpringServiceWithRESTAndJSONExample/service/user/{userid}";
    User user=restTemplate.getForObject(url, User.class,userid);
    return new ModelAndView("dispUser", "user", user);
 }

}

CorsFilter (com.bargadss.CORS) 如下:

package com.bargadss.CORS;

import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.filter.OncePerRequestFilter;


public class CorsFilter extends OncePerRequestFilter{

@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
        throws ServletException, IOException {
    if (request.getHeader("Access-Control-Request-Method") != null && "OPTIONS".equals(request.getMethod())) {
        // CORS "pre-flight" request
        response.addHeader("Access-Control-Allow-Origin", "*");
        response.addHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE");
        response.addHeader("Access-Control-Allow-Headers", "Content-Type");
        response.addHeader("Access-Control-Max-Age", "1800");//30 min
    }
    filterChain.doFilter(request, response);
}

}

web.xml 如下:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
     xmlns="http://java.sun.com/xml/ns/javaee" 
     xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
     id="WebApp_ID" version="3.0">
<display-name>SpringServiceWithRESTAndJSONExample</display-name>

<servlet>
   <servlet-name>rest</servlet-name>
  <servlet-class>
         org.springframework.web.servlet.DispatcherServlet
  </servlet-class>
  <load-on-startup>1</load-on-startup>
</servlet>

<servlet>
  <servlet-name>jsp</servlet-name>
  <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>
</servlet>

<servlet-mapping>
  <servlet-name>rest</servlet-name>
  <url-pattern>/*</url-pattern>
</servlet-mapping>

<servlet-mapping>
 <servlet-name>jsp</servlet-name>
 <url-pattern>/WEB-INF/jsp/*</url-pattern>
</servlet-mapping>

<filter>
  <filter-name>cors</filter-name>
  <filter-class>com.bargadss.CORS.CorsFilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>cors</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

</web-app>

当 AngularJS 从另一个 Web 服务器调用 Web 服务时，返回错误指的是跨源资源共享问题!!!

必须在 Controller 端执行哪些更改才能消除错误？

是否需要在 AngularJS 端进行任何更改以避免这种情况？

Answer 1

检查 cors-filter

下载 cors-filter-2.1.2.jar 和 java-property-utils-1.9.1.jar。

mvn 依赖

<dependency>
    <groupId>com.thetransactioncompany</groupId>
    <artifactId>cors-filter</artifactId>
    <version>2.1.2</version>
</dependency>
<dependency>
  <groupId>com.thetransactioncompany</groupId>
  <artifactId>java-property-utils</artifactId>
  <version>1.9.1</version>
</dependency>

并且在 web.xml

<filter>
    <filter-name>CORS</filter-name>
    <filter-class>com.thetransactioncompany.cors.CORSFilter</filter-class>
</filter>
 <filter-mapping>
        <filter-name>CORS</filter-name>
    <url-pattern>/*</url-pattern>
 </filter-mapping>