关于跨域资源访问请参考 http://en.wikipedia.org/wiki/Cross-origin_resource_sharing ,基本原理是在Spring Controller的每一个请求返回的时候都加上Access-Control-...header,需要注意的是并不是所有的浏览器都支持这些header,使用之前要先了解清楚。
实现起来也很简单那就是Interceptor,代码如下:
public class AccessKeyInterceptor extends HandlerInterceptorAdapter {
private static Log log=LogFactory.getLog(AccessKeyInterceptor.class);
@Autowired
private IAccessService accessService;
private String accessKeyParameterName="accessKey";
private List<String> defaultAccessAllowedFrom;
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
String accessKey=request.getParameter(accessKeyParameterName);
String referer = request.getHeader("Referer");
URL u = new URL(referer);
String host = u.getHost().toLowerCase();
if(accessKey==null){
log.error("====================================ILLEGAL ACCESS: ACCESS_KEY_MISSING!=======================");
}else{
log.debug("====================================ACCESS WITH Access KEY:"+accessKey+"====================");
IAccess access = accessService.getAccess(UserSessionUtils.getUserSession(request), accessKey);
if(access!=null){
defaultAccessAllowedFrom=access.getAccessAllowedFrom();
}else{
log.warn("======================================ACCESS KEY:"+accessKey+" DOES NOT EXIST!=================");
}
}
for(String s : defaultAccessAllowedFrom) {
if(host.matches(s)){
response.setHeader("Access-Control-Allow-Origin", referer);
break;
}
}
response.setHeader("Access-Control-Allow-Headers", "Content-Type");
response.setHeader("Access-Control-Allow-Methods", "GET");
response.setHeader("Allow", "GET");
return true;
}
public List<String> getDefaultAccessAllowedFrom() {
return defaultAccessAllowedFrom;
}
public void setDefaultAccessAllowedFrom(List<String> defaultAccessAllowedFrom) {
this.defaultAccessAllowedFrom = defaultAccessAllowedFrom;
}
public String getAccessKeyParameterName() {
return AccessKeyParameterName;
}
public void setAccessKeyParameterName(String accessKeyParameterName) {
this.AccessKeyParameterName = AccessKeyParameterName;
}
}
其中defaultAccessAllowedFrom是在Spring的配置文件中,主要的配置默认授权访问的url,如下:
<property name="defaultAccessAllowedFrom">
<list>
<value>(.+\.)?(domain\.com)$</value>
<value>(.+\.)?(192\.168\.0\.10)$</value>
</list>
</property>
但是由于Spring默认Controller是不处理OPTIONS的请求的,所以必须在web.xml中打开,如下:
<servlet>
<servlet-name>application</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>dispatchOptionsRequest</param-name>
<param-value>true</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>application</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
这样当请求时POST的时候前段就会自动先请求OPTIONS,得到许可后就可以跨域访问POST请求了。一般我们会在OPTIONS的方法中加上"Allow: OPTIONS,GET,POST"类似header以区分于普通的请求。
转载地址:http://blog.youkuaiyun.com/hyman_xie/article/details/7816991