同源策略是指：协议、主机和端口都相同。我们可以在本地机器上部署2个不同端口的tomcat，让一个tomcat下的应用通过ajax访问另一个tomcat下的rest服务，这样就存在跨域访问问题了。修改conf/server.xml下面的三处端口号：

<Server port="****" shutdown="SHUTDOWN">
    <Connector port="****" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
    <Connector port="****" protocol="AJP/1.3" redirectPort="8443" />

在上一篇博客的基础上，为了解决cxf跨域问题需要：

1.修改pom文件，增加providers

<dependency>
	<groupId>org.apache.cxf</groupId>
	<artifactId>cxf-rt-rs-extension-providers</artifactId>
	<version>${cxf.version}</version>
</dependency>

2.修改cxf-spring.xml配置jsonp拦截器

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:jaxrs="http://cxf.apache.org/jaxrs"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
	http://cxf.apache.org/jaxrs
	http://cxf.apache.org/schemas/jaxrs.xsd">

	<jaxrs:server address="/rest">
		<jaxrs:serviceBeans>
			<ref bean="nameServiceImpl"/>
		</jaxrs:serviceBeans>
		
		<!--jsonp-->
		<jaxrs:providers>
			<bean class="org.apache.cxf.jaxrs.provider.jsonp.JsonpPreStreamInterceptor"/>
		</jaxrs:providers>

		<jaxrs:inInterceptors>
			<bean class="org.apache.cxf.jaxrs.provider.jsonp.JsonpInInterceptor"/>
		</jaxrs:inInterceptors>
		<jaxrs:outInterceptors>
			<bean class="org.apache.cxf.jaxrs.provider.jsonp.JsonpPostStreamInterceptor"/>
		</jaxrs:outInterceptors>
	</jaxrs:server>
	
	
</beans>

3.在另一个tomcat下通过ajax访问

$.ajax({
	  type: 'get',url: 'http://127.0.0.1:8080/aty-rest/rest/rest/welcome',dataType: 'jsonp',jsonp: '_jsonp',jsonpCallback: 'callback',success: function(data) {
		alert(JSON.stringify(data));
	  }
});