Tomcat跨域

先下载 cors-filter-2.6.jar  2.java-property-utils-1.9.1.jar,这两个文件有些在csdn上积分太高，有些要百度网盘，还要下载百度网盘客户端，太麻烦，直接在pom.xml中配置，然后让ide直接去下载就好了，然后去找到这两个文件复制出来即可,pom.xml增加如下配置(maven):

<!-- https://mvnrepository.com/artifact/com.thetransactioncompany/cors-filter -->
<dependency>
    <groupId>com.thetransactioncompany</groupId>
    <artifactId>cors-filter</artifactId>
    <version>2.6</version>
</dependency>

web.xml的配置，从网上抄的

<filter>
        <filter-name>CORS</filter-name>
        <filter-class>com.thetransactioncompany.cors.CORSFilter</filter-class>
        <init-param>
            <param-name>cors.allowOrigin</param-name>
            <param-value>*</param-value>
        </init-param>
        <init-param>
            <param-name>cors.supportedMethods</param-name>
            <param-value>GET,POST,HEAD,PUT,DELETE</param-value>
        </init-param>
        <init-param>
            <param-name>cors.supportedHeaders</param-name>
            <param-value>Accept,Origin,X-Requested-With,Content-Type,Last-Modified</param-value>
        </init-param>
        <init-param>
            <param-name>cors.exposedHeaders</param-name>
            <param-value>Set-Cookie</param-value>
        </init-param>
        <init-param>
            <param-name>cors.supportsCredentials</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CORS</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>  

如果处理好没效果，就试试重启tomcat