Spring的全局异常处理机制+@ControllerAdvice注解的 使用

       对于一些我们自定义的一些异常，或者一些其他的异常信息，我们不希望页面看到一大串bug信息，想友好的提示给用户，这样的需要可以利用的spring的全局异常处理机制实现，spring提供了多种异常处理的方式，下面这个方式只是其中一个，我们项目中是这么用的，参考一下我们项目中的实现，做一次记录。

先认识一个类ResponseEntityExceptionHandler

这个类里面封装了各种可能出现的异常，ResponseEntityExceptionHandler源码如下：

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package org.springframework.web.servlet.mvc.method.annotation;

import java.util.List;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.ConversionNotSupportedException;
import org.springframework.beans.TypeMismatchException;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;
import org.springframework.util.CollectionUtils;
import org.springframework.validation.BindException;
import org.springframework.web.HttpMediaTypeNotAcceptableException;
import org.springframework.web.HttpMediaTypeNotSupportedException;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.MissingPathVariableException;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.ServletRequestBindingException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.ServletWebRequest;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.context.request.async.AsyncRequestTimeoutException;
import org.springframework.web.multipart.support.MissingServletRequestPartException;
import org.springframework.web.servlet.NoHandlerFoundException;
import org.springframework.web.servlet.mvc.multiaction.NoSuchRequestHandlingMethodException;

public abstract class ResponseEntityExceptionHandler {
    public static final String PAGE_NOT_FOUND_LOG_CATEGORY = "org.springframework.web.servlet.PageNotFound";
    protected static final Log pageNotFoundLogger = LogFactory.getLog("org.springframework.web.servlet.PageNotFound");
    protected final Log logger = LogFactory.getLog(this.getClass());

    public ResponseEntityExceptionHandler() {
    }

    @ExceptionHandler({NoSuchRequestHandlingMethodException.class, HttpRequestMethodNotSupportedException.class, HttpMediaTypeNotSupportedException.class, HttpMediaTypeNotAcceptableException.class, MissingPathVariableException.class, MissingServletRequestParameterException.class, ServletRequestBindingException.class, ConversionNotSupportedException.class, TypeMismatchException.class, HttpMessageNotReadableException.class, HttpMessageNotWritableException.class, MethodArgumentNotValidException.class, MissingServletRequestPartException.class, BindException.class, NoHandlerFoundException.class, AsyncRequestTimeoutException.class})
    public final ResponseEntity