实现思路：
1：准备一个ThreadLocal变量，供线程之间共享。
2：每个微服务对所有过来的Feign调用进行过滤，然后从请求头中获取User用户信息，并存在ThreadLocal变量中。
3：每个微服务在使用FeignClient调用别的微服务时，先从ThreadLocal里面取出user信息，并放在request的请求头中。
4：封装为一个注解，在启动类上标记即可。
代码样例：
1：ThreadLocal工具类 ：UserInfoContext
package com.test.domi.common.system;
import com.test.domi.dao.UserInfo;
public class UserInfoContext {
private static ThreadLocal<UserInfo> userInfo = new ThreadLocal<UserInfo>();
public static String KEY_USERINFO_IN_HTTP_HEADER = "X-AUTO-FP-USERINFO";
public UserInfoContext() {
}
public static UserInfo getUser(){
return (UserInfo)userInfo.get();
}
public static void setUser(UserInfo user){
userInfo.set(user);
}
}
2：准备承载用户信息的userInfo实体类（代码略）
3：编写拦截器 ： TransmitUserInfoFeighClientIntercepter
package com.test.domi.config; import com.alibaba.fastjson.JSON;
import com.test.domi.common.system.UserInfoContext;
import com.test.domi.dao.UserInfo;
import feign.RequestInterceptor;
import feign.RequestTemplate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder; public class TransmitUserInfoFeighClientIntercepter implements RequestInterceptor { private static final Logger log = LoggerFactory.getLogger(TransmitUserInfoFeighClientIntercepter.class);
public TransmitUserInfoFeighClientIntercepter() {
} @Override
public void apply(RequestTemplate requestTemplate) {
//从应用上下文中取出user信息，放入Feign的请求头中
UserInfo user = UserInfoContext.getUser();
if (user != null) {
try {
String userJson = JSON.toJSONString(user);
requestTemplate.header("KEY_USERINFO_IN_HTTP_HEADER",new String[]{URLDecoder.decode(userJson,"UTF-8")});
} catch (UnsupportedEncodingException e) {
log.error("用户信息设置错误",e);
}
}
}
}
4：编写过滤器：TransmitUserInfoFilter
package com.test.domi.config; import com.alibaba.fastjson.JSON;
import com.test.domi.common.system.UserInfoContext;
import com.test.domi.dao.UserInfo;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory; import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder; public class TransmitUserInfoFilter implements Filter { private static final Logger log = LoggerFactory.getLogger(TransmitUserInfoFeighClientIntercepter.class);
public TransmitUserInfoFilter() {
}
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
this.initUserInfo((HttpServletRequest)request);
chain.doFilter(request,response);
} private void initUserInfo(HttpServletRequest request){
String userJson = request.getHeader("KEY_USERINFO_IN_HTTP_HEADER");
if (StringUtils.isNotBlank(userJson)) {
try {
userJson = URLDecoder.decode(userJson,"UTF-8");
UserInfo userInfo = (UserInfo) JSON.parseObject(userJson,UserInfo.class);
//将UserInfo放入上下文中
UserInfoContext.setUser(userInfo);
} catch (UnsupportedEncodingException e) {
log.error("init userInfo error",e);
}
}
} @Override
public void destroy() {
}
}
5：编写注解实现类： EnableUserInfoTransmitterAutoConfiguration
package spring.cloud.common.config; import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import spring.cloud.common.interceptor.TransmitUserInfoFeighClientInterceptor;
import spring.cloud.common.filter.TransmitUserInfoFilter; //@Configuration 在业务端通过注解EanbleUserInfoTransmitter加载
public class EnableUserInfoTransmitterAutoConfiguration {
public EnableUserInfoTransmitterAutoConfiguration() {
}
@Bean
public TransmitUserInfoFeighClientInterceptor transmitUserInfo2FeighHttpHeader(){
System.out.println("-----TransmitUserInfoFeighClientInterceptor");
return new TransmitUserInfoFeighClientInterceptor();
}
@Bean
public TransmitUserInfoFilter transmitUserInfoFromHttpHeader(){
System.out.println("-----TransmitUserInfoFilter");
return new TransmitUserInfoFilter();
}
}
6：编写注解 EnableUserInfoTransmitter
package com.test.domi.annotation; import com.test.domi.config.EnableUserInfoTransmitterAutoConfiguration;
import org.springframework.context.annotation.Import; import java.lang.annotation.*; @Documented
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Import({EnableUserInfoTransmitterAutoConfiguration.class})
public @interface EnableUserInfoTransmitter {
}
7：在启动类上标记注解即可使用（无侵入）
package com.test.domi; import com.test.domi.annotation.EnableUserInfoTransmitter;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient; @EnableDiscoveryClient
@SpringBootApplication
@MapperScan("com.test.domi.dao")
@EnableUserInfoTransmitter
public class TestCommonClient { public static void main(String[] args){ SpringApplication.run(TestCommonClient.class,args);
}
}