注解使用案例

注解：

import java.lang.annotation.*;

/**
 *
 * 注解在controller方法上
 * 表示可以使用代理人这个功能的接口
 */

@Inherited
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface CanProxy {
}

拦截器处理注解：

import com.nd.gaea.rest.security.authens.UserInfo;
import nd.sdp.idea.base.annotation.CanProxy;
import nd.sdp.idea.base.support.ContextHolder;
import nd.sdp.idea.exception.BizException;
import nd.sdp.idea.exception.ErrorCode;
import nd.sdp.idea.modules.proxy.entity.Proxy;
import nd.sdp.idea.modules.proxy.service.ProxyService;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 代理人身份解析验证拦截器
 * @author yanguanyu(290536)
 * @since 0.1 created on 2016/10/18.
 */
public class ProxyResolveInterceptor extends HandlerInterceptorAdapter {

    private static final Logger logger = LoggerFactory.getLogger(ProxyResolveInterceptor.class);

    private ContextHolder context = ContextHolder.getBean(ContextHolder.class);
    private ProxyService proxyService = ContextHolder.getBean(ProxyService.class);

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        if (authentication == null || "anonymousUser".equals(authentication.getPrincipal())) {
            return true;
        }
        UserInfo userInfo = (UserInfo) authentication.getPrincipal();
        context.setUserInfo(userInfo);

        if (canProxy(handler)) {
            String principalId = request.getHeader("principal");
            Proxy proxy = proxyService.canProxyFor(context.getUserId(), principalId);
            if (proxy != null) {  // 代理人存在 设置代理人信息
                context.setPrincipalId(proxy.getUserId());
                context.setPrincipalUserName(proxy.getUserName());
            } else if(StringUtils.isEmpty(principalId)) { // 请求代理人信息为空 代理人信息设置为登录人信息
                context.setPrincipalId(context.getUserId());
                context.setPrincipalUserName(context.getUserName());
            } else {
                throw new BizException(ErrorCode.PROXY_ACCESS_DENIED, String.format("没有代理用户%s的权限", principalId));
            }
        }
        else { // 没有注解 代理人信息设置为登录人信息
            context.setPrincipalId(context.getUserId());
            context.setPrincipalUserName(context.getUserName());
        }

        return super.preHandle(request, response, handler);
    }
    // 验证目标方法是否有该注解 
    private boolean canProxy(Object handler) {
        if (! (handler instanceof HandlerMethod)) return false;
        CanProxy annotationOnMethod = ((HandlerMethod) handler).getMethodAnnotation(CanProxy.class);
        return annotationOnMethod != null;
    }

}

上下文：

import com.nd.gaea.rest.security.authens.UserInfo;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;

/**
 * 借助RequestContextHolder来保存请求中的身份等上下文信息<br/>
 * @author yanguanyu(290536)
 * @since 0.1 created on 2016/10/18.
 */
@Component
public class ContextHolder implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    private final static String KEY_USER_INFO = "user_info"; //当前用户信息
    private final static String KEY_PRINCIPAL_ID = "principal_id"; //委托人（被代理人）用户id
    private final static String KEY_PRINCIPAL_USER_NAME = "principal_user_name"; //委托人（被代理人）用户名称

    private ContextHolder(){}

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        initContextHolder(applicationContext);
    }

    private static void initContextHolder(ApplicationContext context) {
        ContextHolder.applicationContext = context;
    }

    public static ApplicationContext getApplicatinContext() {
        return applicationContext;
    }

    // 获取与当前线程绑定的HttpServletRequest对象
    public HttpServletRequest getRequest() {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        return attributes.getRequest();
    }

    public static Object getBean(String name) {
        return applicationContext.getBean(name);
    }

    public static <T> T getBean(String name, Class<T> requiredType) {
        return applicationContext.getBean(name, requiredType);
    }

    public static <T> T getBean(Class<T> requiredType) {
        return applicationContext.getBean(requiredType);
    }

    public void setUserInfo(UserInfo userInfo) {
        getRequest().setAttribute(KEY_USER_INFO, userInfo);
    }

    public UserInfo getUserInfo() {
        return (UserInfo) getRequest().getAttribute(KEY_USER_INFO);
    }

    public String getUserId() {
        return (String) getUserInfo().getUserId();
    }

    public String getUserName() {
        return (String) getUserInfo().getOrgExinfo().get("real_name");
    }

    //设置委托人用户id，如果没有使用代理人功能，这个值与getUserId()相同
    public void setPrincipalId(String principalId) {
        getRequest().setAttribute(KEY_PRINCIPAL_ID, principalId);
    }

    public String getPrincipalId() {
        return (String) getRequest().getAttribute(KEY_PRINCIPAL_ID);
    }

    //设置委托人用户名称，如果没有使用代理人功能，这个值与getUserName()相同
    public void setPrincipalUserName(String principalUserName) {
        getRequest().setAttribute(KEY_PRINCIPAL_USER_NAME, principalUserName);
    }

    public String getPrincipalUserName() {
        return (String) getRequest().getAttribute(KEY_PRINCIPAL_USER_NAME);
    }
}