自定义注解开发2

需求

前端向后台发起请求时，希望某些请求需要校验token，某些请求不需要校验token，而只要在方法上加上注解的，系统会自动的去校验token参数。同时，希望系统能自动的根据我们的业务代码抛出的异常类型，抓取后返回前端自定义的异常信息

• 注解类

@Documented
@Target({ElementType.TYPE,ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface Login
{
}

• 自定义拦截器类

@Component
public class BaseHandlerInterceptor implements HandlerInterceptor
{
    @Autowired
    RequestMappingHandlerMapping handlerMapping;
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
    {

        return hasPermission(handler,request);
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
            throws Exception
    {

    }

    @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception
    {

    }


    private boolean hasPermission(Object handler,HttpServletRequest req) {
        if (handler instanceof HandlerMethod) {
            HandlerMethod handlerMethod = (HandlerMethod) handler;
            // 获取方法上的注解
            Login login = handlerMethod.getMethod().getAnnotation(Login.class);
            // 如果方法上的注解为空 则获取类的注解
            if (login == null) {
                login = handlerMethod.getMethod().getDeclaringClass().getAnnotation(Login.class);
            }
            // 如果标记了注解，则判断权限
            if (login != null) {
                String token = req.getParameter("token");
                if(token==null){
                    AssertUtils.INSTANCE.isTrue(false,"token值为空，请求服务失败");
                }
                if(!token.equals("45678")){
                    AssertUtils.INSTANCE.isTrue(false,"token校验失败");
                }
            }
        }
        return true;
    }
}

• 拦截器配置类

@Configuration
public class MVCConfig implements WebMvcConfigurer
{
    @Autowired
    BaseHandlerInterceptor baseHandlerInterceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry)
    {
        registry.addInterceptor(baseHandlerInterceptor).addPathPatterns("/**");
    }
}

• springboot 启动类

@Configuration
@EnableAutoConfiguration
@ComponentScan("com.ppamos.controller")
@ComponentScan("com.ppamos.Dispatcher")
@ComponentScan("com.ppamos.annoatations")
@ComponentScan("com.ppamos.exceptionDeal")
@ComponentScan("com.ppamos.config")
public class MyApplication {
    public static void main(String[] args) throws Exception {
        SpringApplication.run(MyApplication.class, args);
    }

}

• 自定义异常类

public class BusinessException extends RuntimeException
{
    public BusinessException(){
        super();
    }
    public BusinessException(String msg){
        super(msg);
    }
    public BusinessException(String msg, Throwable cause){
        super(msg,cause);
    }
}

• 全局异常处理类

@ControllerAdvice
@ResponseBody
public class GlobalExceptionHandler
{
    //运行时异常
    @ExceptionHandler(RuntimeException.class)
    public Object runtimeExceptionHandler(RuntimeException ex) {
        MobRes mobRes = new MobRes();
        mobRes.setCode(ResponseCode.SERVER_EXCEPTION.getCode());
        mobRes.setMsg(ResponseCode.SERVER_EXCEPTION.getDesc());
        return mobRes;
    }

    @ExceptionHandler(BusinessException.class)
    public Object businessExceptionHandler(BusinessException ex) {
        MobRes mobRes = new MobRes();
        mobRes.setCode(ResponseCode.SERVER_EXCEPTION.getCode());
        mobRes.setMsg(ex.getMessage());
        return mobRes;
    }

}

• 断言工具类

public enum AssertUtils
{
    //单例模式
    INSTANCE;
    public void isTrue(boolean b,String msg) throws BusinessException
    {
        if(b==false){
            throw new BusinessException(msg);
        }
    }
}

• 返回码类

public class MobRes
{
    private int code;   //返回码 
    private String msg; //消息提示

    public MobRes(){
        this.code=ResponseCode.SUCCESS.getCode();
        this.msg=ResponseCode.SUCCESS.getDesc();
    }

    public int getCode()
    {
        return code;
    }

    public void setCode(int code)
    {
        this.code = code;
    }

    public String getMsg()
    {
        return msg;
    }

    public void setMsg(String msg)
    {
        this.msg = msg;
    }
}

public class CommonMobRes<T> extends MobRes
{

    public CommonMobRes(T result){
        this.result=result;
    }
    private T result;

    public T getResult()
    {
        return result;
    }

    public void setResult(T result)
    {
        this.result = result;
    }
}

public enum  ResponseCode
{
    SUCCESS(100, "处理成功"),
    SERVER_EXCEPTION(900, "服务器异常，请您稍后访问！"),;

    private Integer code;
    private String  desc;

     ResponseCode(Integer code,String desc){
        this.code=code;
        this.desc=desc;
    }



    public Integer getCode(){
        return code;
    }

    public String getDesc(){
         return desc;
    }

}

• controller类

@RestController
public class TestController {

    @Autowired
    private HandlerDispatcherServlet handlerDispatcherServlet;


    @RequestMapping("/test")
    public CommonMobRes test(@RequestParam int cmd){
        return  new CommonMobRes<Object>(handlerDispatcherServlet.handle(cmd));
    }

    @Login
    @RequestMapping("/test1")
    public CommonMobRes test1(@RequestParam int cmd,@RequestParam String token){
        return  new CommonMobRes<Object>(handlerDispatcherServlet.handle(cmd));
    }
}

• 最终结果

请求1：localhost:8081/test?cmd=1
结果：
{
    "code": 100,
    "msg": "处理成功",
    "result": "handle register request"
}
请求2：localhost:8081/test1?cmd=1
结果：
{
    "code": 900,
    "msg": "token值为空，请求服务失败"
}
请求3：localhost:8081/test1?cmd=1&&token=1234
结果：
{
    "code": 900,
    "msg": "token校验失败"
}
请求4：localhost:8081/test1?cmd=1&&token=45678
结果：
{
    "code": 100,
    "msg": "处理成功",
    "result": "handle register request"
}