Spring自定义注解（parameter）

1、新建注解接口VerifyAccount.java：

package com.zero4j.annotation;

import java.lang.annotation.Documented;
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)
@Documented

public @interface VerifyAccount {

	String paramName() default "token";
	
	String permission() default "";
}

2、创建注解对应的切面类VerifyAccountAspect.java：

package com.zero4j.annotation;

import net.sf.json.JSONObject;

import org.aspectj.lang.annotation.Aspect;
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.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.multipart.support.MissingServletRequestPartException;

import com.zero4j.model.account.Account;
import com.zero4j.model.token.util.TokenStaticUtil;

@Aspect
@Component
public class VerifyAccountAspect implements HandlerMethodArgumentResolver{

	@Override
	public boolean supportsParameter(MethodParameter parameter) {
		return parameter.hasParameterAnnotation(VerifyAccount.class);
	}

	@Override
	public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
		
		String token = webRequest.getParameter("token");
		
		 JSONObject out = new JSONObject();
		
		if(token==null||token.equals("")){
			out.put("status", 401);
			out.put("message", "请先注册并登录后再进行此操作");
			out.put("debug", "缺少参数token或为空");
			//ResponseStaticUtil.write(response,out);
			System.out.println(out.toString());
			//return;
		}
		Account account = TokenStaticUtil.getAccount(token);
		if(account==null){
			out.put("status", 401);
			out.put("message", "请先注册并登录后再进行此操作");
			out.put("debug", "token对应的account为空");
			//ResponseStaticUtil.write(response,out);
			System.out.println(out.toString());
			throw new MissingServletRequestPartException("account");
			//return;
		}
		
		return account;
	}
	
}

注意要实现接口：HandlerMethodArgumentResolver

3、最后要在SpringMVC的配置java类中加入对应的代码：

package com.zero4j.config;

import java.util.List;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import com.zero4j.annotation.VerifyAccountAspect;

@Configuration
public class WebAppConfigurer implements WebMvcConfigurer {


	@Override
	public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
		
		resolvers.add(new VerifyAccountAspect());
		
		WebMvcConfigurer.super.addArgumentResolvers(resolvers);
	}

}

注意这行：resolvers.add(new VerifyAccountAspect());