java SSM 解决跨域问题

太过爱你忘了你带给我的痛 2022-05-18 09:20 374阅读 0赞

### **1.什么是跨域请求** ###

由于浏览器同源策略，凡是发送请求url的协议、域名、端口三者之间任意一与当前页面地址不同即为跨域。具体可以查看下表

![70][]

### **2.解决跨域请求** ###

**1. 新建一个过滤器，并实现 Filter 接口**

package hbsi.yfzx.filter;
    
    import java.io.IOException;
    
    import javax.servlet.Filter;
    import javax.servlet.FilterChain;
    import javax.servlet.FilterConfig;
    import javax.servlet.ServletException;
    import javax.servlet.ServletRequest;
    import javax.servlet.ServletResponse;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    /**
     * 解决SSM跨域问题
     * @author lzch
     *
     */
    public class SimpleCORSFilter implements Filter {
        private boolean isCross = false;
    
        public void destroy() {
            isCross = false;
        }
    
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
                throws IOException, ServletException {
            if (isCross) {
                HttpServletRequest httpServletRequest = (HttpServletRequest) request;
                HttpServletResponse httpServletResponse = (HttpServletResponse) response;
                System.out.println("拦截请求: " + httpServletRequest.getServletPath());
                httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");
                httpServletResponse.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
                httpServletResponse.setHeader("Access-Control-Max-Age", "0");
                httpServletResponse.setHeader("Access-Control-Allow-Headers",
                        "Origin, No-Cache, X-Requested-With, If-Modified-Since, Pragma, Last-Modified, Cache-Control, Expires, Content-Type, X-E4M-With,userId,token");
                httpServletResponse.setHeader("Access-Control-Allow-Credentials", "true");
                httpServletResponse.setHeader("XDomainRequestAllowed", "1");
            }
            chain.doFilter(request, response);
        }
    
        public void init(FilterConfig filterConfig) throws ServletException {
            String isCrossStr = filterConfig.getInitParameter("IsCross");
            isCross = isCrossStr.equals("true") ? true : false;
            System.out.println(isCrossStr);
        }
    
    
    
    }

2.在web.xml中配置

<filter>
    		<filter-name>SimpleCORSFilter</filter-name>
    		<filter-class>hbsi.yfzx.filter.SimpleCORSFilter</filter-class>
    		<init-param>
    			<param-name>IsCross</param-name>
    			<param-value>true</param-value>
    		</init-param>
    	</filter>
    	<filter-mapping>
    		<filter-name>SimpleCORSFilter</filter-name>
    		<url-pattern>/*</url-pattern>
    	</filter-mapping>

3.**. 在SpringMVC 的配置文件中配置跨域请求**

<mvc:cors>  
              <mvc:mapping path="/**"  
                           allowed-origins="*"  
                           allowed-methods="POST, GET, OPTIONS, DELETE, PUT"  
                           allowed-headers="Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With"  
                           allow-credentials="true" />  
          </mvc:cors>

[70]: /images/20220518/81f536d2cd6b4be0a5b8975d6331dd0d.png