1.定义Token的注解，需要Token校验的接口，方法上加上此注解

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface Token {
boolean validate() default true;
}

2.定义LoginUser注解，此注解加在参数上，用在需要从token里获取的用户信息的地方

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
public @interface LoginUser {
}

3.权限的校验拦截器

import com.example.demo.annotation.Token;
import com.example.demo.entity.User;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@Component
@Slf4j
public class AuthorizationInterceptor extends HandlerInterceptorAdapter {
public static final String USER_KEY = "USER_ID";
public static final String USER_INFO = "USER_INFO";
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
Token annotation;
if(handler instanceof HandlerMethod) {
annotation = ((HandlerMethod) handler).getMethodAnnotation(Token.class);
}else{
return true;
}
//没有声明需要权限,或者声明不验证权限
if(annotation == null || annotation.validate() == false){
return true;
}
//从header中获取token
String token = request.getHeader("token");
if(token == null){
log.info("缺少token，拒绝访问");
return false;
}
//查询token信息
// User user = redisUtils.get(USER_INFO+token,User.class);
// if(user == null){
// log.info("token不正确，拒绝访问");
// return false;
// }
//token校验通过，将用户信息放在request中，供需要用user信息的接口里从token取数据
request.setAttribute(USER_KEY, "123456");
User user=new User();
user.setId(10000L);
user.setUserName("yin@yinzhongnet.com");
user.setPhoneNumber("15702911111");
user.setToken(token);
request.setAttribute(USER_INFO, user);
return true;
}
}

4.写参数的解析器，将登陆用户对象注入到接口里

import com.example.demo.annotation.LoginUser;
import com.example.demo.entity.User;
import com.example.demo.interceptor.AuthorizationInterceptor;
import org.springframework.core.MethodParameter;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
@Component
public class LoginUserHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver
{
@Override
public boolean supportsParameter(MethodParameter methodParameter) {
return methodParameter.getParameterType().isAssignableFrom(User.class)&&methodParameter.hasParameterAnnotation(LoginUser.class);
}
@Override
public Object resolveArgument(MethodParameter methodParameter, ModelAndViewContainer modelAndViewContainer, NativeWebRequest nativeWebRequest, WebDataBinderFactory webDataBinderFactory) throws Exception {
//获取登陆用户信息
Object object = nativeWebRequest.getAttribute(AuthorizationInterceptor.USER_INFO, RequestAttributes.SCOPE_REQUEST);
if(object == null){
return null;
}
return (User)object;
}
}

5.配置拦截器和参数解析器

import com.example.demo.interceptor.AuthorizationInterceptor;
import com.example.demo.resolver.LoginUserHandlerMethodArgumentResolver;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import java.util.List;

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
@Autowired
private AuthorizationInterceptor authorizationInterceptor;
@Autowired
private LoginUserHandlerMethodArgumentResolver loginUserHandlerMethodArgumentResolver;

@Override
public void addInterceptors(InterceptorRegistry registry) {
// addPathPatterns("/**") 表示拦截所有的请求，
// addPathPatterns("/api/**") 表示拦截/api/ 下的所有路径请求，
// addPathPatterns("/api/*") 表示拦截/api/abc，拦截/api/aaa , 不拦截 /api/abc/def
// addPathPatterns("/api/**").excludePathPatterns("/api/login", "/api/register") 表示拦截/api/ 下的所有路径请求，但不拦截 /api/login 和 /api/register
registry.addInterceptor(authorizationInterceptor).addPathPatterns("/api/**");
}

@Override
public void addArgumentResolvers(List argumentResolvers) {
argumentResolvers.add(loginUserHandlerMethodArgumentResolver);
}
}

6.测试类

import com.example.demo.annotation.LoginUser;
import com.example.demo.annotation.Token;
import com.example.demo.entity.User;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping(value = "/api")
@Slf4j
public class TestController {
@RequestMapping(value="/test",method = RequestMethod.POST)
@Token
public String test(@LoginUser User user){
System.out.println("需要token才可以访问，呵呵……");
log.info("user："+user.toString());
return "test";
}
@RequestMapping(value="/noToken",method = RequestMethod.POST)
public String noToken(){
System.out.println("不用token就可以访问……");
return "test";
}
}

至此，自定义注解实现token校验就大功告成了。