官方推荐方式：
http://spring.io/blog/2015/06/08/cors-support-in-spring-framework
方式1：
$.ajax({ //前台：常规写法。注意：如果用注解dataType别写成了JSONP 要写成JSON 两都有区别。一个是协议一个是数据格式(个人理解)
url:'http://localhost:8082/cors/corsTest.do',
data:{},
dataType:'json',
type:'post',
success:function(data){
alert(data.abc);
}
})
// 后台代码 。。。 添加注解即可。CrossOrigin(这里可能配置多个地址。不配置默认全部 可以配置到controller上面。也可以配置方法上。都配置他会自动合并)
@SuppressWarnings("unchecked")
@RequestMapping(value="/corsTest",method = RequestMethod.POST)
@ResponseBody
@CrossOrigin
public Object corsTest(){
Map map = new HashMap();
map.put("abc", 123);
return map;
}
方式2:
$.ajax({ //不采用注解方法，手动拼一个callback字符串。
url:'http://localhost:8082/cors/corsTest1.do',
data:{},
async:false,
dataType:'jsonp',
jsonpCallback:"callback",
type:'post',
success:function(data){
alert(data.abc);
}
})
后台代码：
@RequestMapping(value="/corsTest1")
@ResponseBody
public Object corsTest1(){
Map map = new HashMap();
map.put("abc", 456);
return "callback("+JSON.toJSONString(map)+")";
}
方式3：
即不采用注解也不采用手动拼接字符串的方式 。就是用拦截器方式；
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
try {
HttpServletRequest httpRequest = (HttpServletRequest) request;
HttpServletResponse httpResponse = (HttpServletResponse) response;
// 跨域
String origin = httpRequest.getHeader("Origin");
if (origin == null) {
httpResponse.addHeader("Access-Control-Allow-Origin", "*");
} else {
httpResponse.addHeader("Access-Control-Allow-Origin", origin);
}
httpResponse.addHeader("Access-Control-Allow-Headers", "Origin, x-requested-with, Content-Type, Accept,X-Cookie");
httpResponse.addHeader("Access-Control-Allow-Credentials", "true");
httpResponse.addHeader("Access-Control-Allow-Methods", "GET,POST,PUT,OPTIONS,DELETE");
if ( httpRequest.getMethod().equals("OPTIONS") ) {
httpResponse.setStatus(HttpServletResponse.SC_OK);
return;
}
chain.doFilter(request, response);
} catch (Exception e) {
logger.error("Exception in crossFilter", e);
throw e;
}
}
然后在web.xml配置一下就行了。
<filter>
<filter-name>crossDemoFilter</filter-name>
<filter-class>com.shanreal.filter.crossFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>crossDemoFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
还有一种就是通过nginx配置。学习中
