摘要：
在Extjs和Java项目中，会遇到跨域处理和外部访问后台接口的问题。原始代码如下：只有一个跨域请求packagecom.xgt。可以设置extjs前台需要过滤的配置；importjavax.servlet.*；importjavax.servlet.http。HttpServletRequest；importjavax.servlet.http.HttpServlet响应
在Extjs和java项目碰到了需要同时处理跨域，外部要访问后台接口的问题
原来的代码是这样，只能设置一个extjs前台需要过滤的跨域请求
package com.xgt.config; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.Arrays; import java.util.HashSet; import java.util.Set; /** * 解决跨域问题 */ public class SimpleCORSFilter implements Filter { public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { HttpServletResponse response = (HttpServletResponse) res; response.setHeader("Access-Control-Allow-Origin", "http://127.0.0.1:1841"); response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "content-type, x-requested-with"); response.setHeader("Access-Control-Allow-Credentials", "true");
chain.doFilter(req, res);} public void init(FilterConfig filterConfig) {} public void destroy() {} }
略微改进，给同局域网的同事访问我的接口，我设置的ip是同事的192.168.1.178，是因为他的ip访问我的接口会遭到拦截，我自己的ip不会被拦截，所以不用设置
package com.xgt.config; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.Arrays; import java.util.HashSet; import java.util.Set; /** * 解决跨域问题 */ public class SimpleCORSFilter implements Filter { public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { HttpServletResponse response = (HttpServletResponse) res; String [] allowDomain= {"http://127.0.0.1:1841","http://192.168.1.178"}; Set<String> allowedOrigins= new HashSet<String>(Arrays.asList(allowDomain)); String originHeader=((HttpServletRequest) req).getHeader("Origin"); if (allowedOrigins.contains(originHeader)) { response.setHeader("Access-Control-Allow-Origin", originHeader); response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "content-type, x-requested-with"); response.setHeader("Access-Control-Allow-Credentials", "true"); } chain.doFilter(req, res); } public void init(FilterConfig filterConfig) {} public void destroy() {} }
还有一种SB写法，直接根据originHeader的结果来判断，if语句简单粗暴
HttpServletResponse response = (HttpServletResponse) res; String originHeader=((HttpServletRequest) req).getHeader("Origin"); if ("http://127.0.0.1:1841".equals(originHeader)) { response.setHeader("Access-Control-Allow-Origin", "http://127.0.0.1:1841"); response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "content-type, x-requested-with"); response.setHeader("Access-Control-Allow-Credentials", "true"); }else if("http://192.168.1.178".equals(originHeader)){ response.setHeader("Access-Control-Allow-Origin", "http://192.168.1.178"); response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "content-type, x-requested-with"); response.setHeader("Access-Control-Allow-Credentials", "true"); }else if(originHeader==null){ chain.doFilter(req,res); } chain.doFilter(req, res);