一些模块

1.全局异常处理

出现异常时希望返回自定义的异常界面

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.servlet.ModelAndView;

@ControllerAdvice//拦截所有带有@controller注解的控制器
public class ControllerExceptionHandler {

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

    @ExceptionHandler({Exception.class})//标识这个方法做异常处理
    public ModelAndView handleException(HttpServletRequest request, Exception e) throws Exception {
        //{}占位作用
        logger.error("Request URL : {} , Exception : {}", request.getRequestURL(), e);
        //不会拦截自己写的异常
        if (AnnotationUtils.findAnnotation(e.getClass(), ResponseStatus.class) != null) {
            throw e;
        }
        ModelAndView mav = new ModelAndView();
        mav.addObject("url", request.getRequestURL());
        mav.addObject("exception", e);
        //返回路径
        mav.setViewName("error/error");
        return mav;
    }
}

在错误界面异常信息显示处理

<div>
    <div th:utext="'<!--'" th:remove="tag">div>
    <div th:utext="'Failed Request URL : ' + ${url}" th:remove="tag">div>
    <div th:utext="'Exception message : ' + ${exception.message}" th:remove="tag">div>
    <ul th:remove="tag">
        <li th:each="st : ${exception.stackTrace}" th:remove="tag"><span th:utext="${st}" th:remove="tag">span>li>
    ul>
    <div th:utext="'-->'" th:remove="tag">div>
div>

之后在错误页面中右键选择“查看网页源代码”就可以在网页上查看错误信息，方便调试。

2. 自定义异常处理

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(HttpStatus.NOT_FOUND)
public class NotFoundException extends  RuntimeException{
    public NotFoundException() {
        super();
    }

    public NotFoundException(String message) {
        super(message);
    }

    public NotFoundException(String message, Throwable cause) {
        super(message, cause);
    }
}

//if(blog==null){
// throw new NotFoundException(“博客不存在”);
// }

3.日志处理

记录日志内容：

• 请求url
• 访问者ip
• 调用方法classMethod
• 参数args
• 返回内容

@Aspect
@Component
public class LogAspect {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Pointcut("execution(* com.lga.blogdemo.web.*.*(..))")
    public void log(){}

    @Before("log()")
    public void doBefore(JoinPoint joinPoint){
        logger.info("-----------doBefore----------------");
        ServletRequestAttributes attributes= (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = attributes.getRequest();
        String url = request.getRequestURL().toString();
        String ip = request.getRemoteAddr();
        String classMethod = joinPoint.getSignature().getDeclaringTypeName()+"."+joinPoint.getSignature().getName();
        Object[] args = joinPoint.getArgs();
        RequestLog requestLog = new RequestLog(url,ip,classMethod,args);
        logger.info("Request : {}",requestLog);
    }
    @After("log()")
    public void doAfter(){
        logger.info("-----------doAfter-----------------");
    }
    @AfterReturning(returning = "result",pointcut = "log()")
    public void doAfterReturn(Object result){
        logger.info("Result : {}",result);

    }

    private class RequestLog{
        private String url;
        private String ip;
        private String classMethod;
        private Object[] args;

        @Override
        public String toString() {
            return "RequestLog{" +
                    "url='" + url + '\'' +
                    ", ip='" + ip + '\'' +
                    ", classMethod='" + classMethod + '\'' +
                    ", args=" + Arrays.toString(args) +
                    '}';
        }

        public String getUrl() {
            return url;
        }
        public void setUrl(String url) {
            this.url = url;
        }
        public String getIp() {
            return ip;
        }
        public void setIp(String ip) {
            this.ip = ip;
        }
        public String getClassMethod() {
            return classMethod;
        }
        public void setClassMethod(String classMethod) {
            this.classMethod = classMethod;
        }
        public Object[] getArgs() {
            return args;
        }
        public void setArgs(Object[] args) {
            this.args = args;
        }
        public RequestLog(String url, String ip, String classMethod, Object[] args) {
            this.url = url;
            this.ip = ip;
            this.classMethod = classMethod;
            this.args = args;
        }
    }
}