Shulou(Shulou.com)06/03 Report--

这篇文章给大家介绍Java服务器端跨域问题的解决方法，内容非常详细，感兴趣的小伙伴们可以参考借鉴，希望对大家能有所帮助。

现在很多开发的 API 都支持 ajax 直接请求，这样就会导致跨域的问题，解决跨域的问题一方面可以从前端，另一方面就是服务器端。

一、Controller类名上方添加@CrossOrigin 注解通过此方式注解则Controller中的所有通过@RequestMapping注解的方法都可以进行跨域请求。 代码如下：

@CrossOrigin() @RequestMapping("/demoController") @Controller public class DemoController { @Autowired IDemoService demoService; @RequestMapping(value = "/test", method = RequestMethod.POST) @ResponseBody public ResultModel test(HttpServletRequest request) throws Exception { return "right"; }}

二、让所有的controller类继承自定义的BaseController类,该类中将对返回的头部做些特殊处理。

public abstract class BaseController { /** * description:send the ajax response back to the client side * @param responseObj * @param response */ protected void writeAjaxJSONResponse(Object responseObj, HttpServletResponse response) { response.setCharacterEncoding("UTF-8"); response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1 response.setHeader("Pragma", "no-cache"); // HTTP 1.0 /** * for ajax-cross-domain request TODO get the ip address from * configration(ajax-cross-domain.properties) */ response.setHeader("Access-Control-Allow-Origin", "*"); response.setDateHeader("Expires", 0); // Proxies. PrintWriter writer = getWriter(response); writeAjaxJSONResponse(responseObj, writer); } /** * * @param response * @return */ protected PrintWriter getWriter(HttpServletResponse response) { if(null == response){ return null; } PrintWriter writer = null; try { writer = response.getWriter(); } catch (IOException e) { logger.error("unknow exception", e); } return writer; } /** * description:send the ajax response back to the client side. * * @param responseObj * @param writer * @param writer */ protected void writeAjaxJSONResponse(Object responseObj, PrintWriter writer) { if (writer == null || responseObj == null) { return; } try { writer.write(JSON.toJSONString(responseObj,SerializerFeature.DisableCircularReferenceDetect)); } finally { writer.flush(); writer.close(); } }}接下来就是我们自己业务的 controller 了，其中主要是要调用 writeAjaxJSONResponse(result, response); 这个方法@Controller@RequestMapping(value = "/account")public class AccountController extends BaseController {@RequestMapping(value = "/add", method = RequestMethod.POST) public void addAccount(HttpSession session,HttpServletRequest request,HttpServletResponse response){ ViewerResult result = new ViewerResult(); //实现自己业务逻辑代码 writeAjaxJSONResponse(result, response); }}好了，这种简单的方式就实现了。

三、Filter,我们在写springMVC的时候，更喜欢的方式是通过@ResponseBody给返回对象进行封装直接返回给前端，这样简单而且容易。 如果使用@ResponseBody就不能使用第一种方法了，所有就使用filter给所有的请求都封装一下跨域，接下来直接实现代码：

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.HttpServletResponse;public class HeadersCORSFilter implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { // TODO Auto-generated method stub } @Override public void doFilter(ServletRequest request, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException { HttpServletResponse response = (HttpServletResponse) servletResponse; response.setHeader("Access-Control-Allow-Origin", "*"); response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "x-requested-with,Authorization"); response.setHeader("Access-Control-Allow-Credentials","true"); chain.doFilter(request, servletResponse); } @Override public void destroy() { // TODO Auto-generated method stub }}好了，filter 实现了，然后就是要在 web.xml 里面把这个 filter 运用起来了。打开项目的 web.xml，填写下面的几行代码：cors xxx.xxxx.xxxxx.xxxx.HeadersCORSFilter cors /open/* 好了，通过上面的3种方式，可以解决百分之80的跨域问题，也许还有更好的解决方案，可以提出来大家一起学习学习。最好的方案是最符合当前需求且易于扩展的。

关于Java服务器端跨域问题的解决方法就分享到这里了，希望以上内容可以对大家有一定的帮助，可以学到更多知识。如果觉得文章不错，可以把它分享出去让更多的人看到。

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