跨域是比较常见问题，比较简单的方式就是直接定义一个过滤器filter，然后在请求头里面加上一些参数。下面来看看具体的写法吧。
一、java代码
package com.hj.userapi.core.filter;
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;
/**
* 功能描述：解决跨域过滤器
* 2017年9月4日
*/
public class ContextFilter implements Filter{
private final int time = 20*24*60*60;
/**
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
@Override
public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub
}
/**
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletResponse resp = (HttpServletResponse) response;
// 添加参数，允许任意domain访问
resp.setHeader("Access-Control-Allow-Origin", "*");
// 这个allow-headers要配为*，这样才能允许所有的请求头 --- update by zxy in 2018-10-19
resp.setHeader("Access-Control-Allow-Headers", "*");
resp.setHeader("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
resp.setHeader("Access-Control-Max-Age", time+"");
chain.doFilter(request, resp);
}
/**
* @see javax.servlet.Filter#destroy()
*/
@Override
public void destroy() {
// TODO Auto-generated method stub
}
}x
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package com.hj.userapi.core.filter;
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import java.io.IOException;
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import javax.servlet.Filter;
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import javax.servlet.FilterChain;
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import javax.servlet.FilterConfig;
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import javax.servlet.ServletException;
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import javax.servlet.ServletRequest;
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import javax.servlet.ServletResponse;
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import javax.servlet.http.HttpServletResponse;
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/**
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* 功能描述：解决跨域过滤器
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* 2017年9月4日
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*/
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public class ContextFilter implements Filter{
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private final int time = 20*24*60*60;
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/**
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* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
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*/
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public void init(FilterConfig filterConfig) throws ServletException {
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// TODO Auto-generated method stub
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}
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/**
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* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
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*/
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public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
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HttpServletResponse resp = (HttpServletResponse) response;
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// 添加参数，允许任意domain访问
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resp.setHeader("Access-Control-Allow-Origin", "*");
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// 这个allow-headers要配为*，这样才能允许所有的请求头 --- update by zxy in 2018-10-19
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resp.setHeader("Access-Control-Allow-Headers", "*");
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resp.setHeader("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
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resp.setHeader("Access-Control-Max-Age", time+"");
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chain.doFilter(request, resp);
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}
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/**
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* @see javax.servlet.Filter#destroy()
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*/
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public void destroy() {
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// TODO Auto-generated method stub
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}
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}
二、web.xml中的配置
<filter>
<filter-name>contextFilter</filter-name>
<filter-class>com.hj.userapi.core.filter.ContextFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>contextFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
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<filter>
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<filter-name>contextFilter</filter-name>
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<filter-class>com.hj.userapi.core.filter.ContextFilter</filter-class>
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</filter>
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<filter-mapping>
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<filter-name>contextFilter</filter-name>
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<url-pattern>/*</url-pattern>
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</filter-mapping>
三、小结
通过自定义过滤器，在请求头上添加参数实现允许容易域名访问来解决跨域问题，实现起来比较简单。
原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/15530.html