@ControllerAdvice是Spring 3.2新增的注解，主要是用来Controller的一些公共的需求的低侵入性增强提供辅助，作用于@RequestMapping标注的方法上。

ControllerAdvice的定义如下：

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Componentpublic @interface ControllerAdvice {    /**     * Alias for the {
    @link #basePackages} attribute.     * 
Allows for more concise annotation declarations e.g.:     * {
    @code @ControllerAdvice("org.my.pkg")} is equivalent to     * {
    @code @ControllerAdvice(basePackages="org.my.pkg")}.     * @since 4.0     * @see #basePackages()     */    @AliasFor("basePackages")    String[] value() default {};    /**     * Array of base packages.     * 
Controllers that belong to those base packages or sub-packages thereof     * will be included, e.g.: {
    @code @ControllerAdvice(basePackages="org.my.pkg")}     * or {
    @code @ControllerAdvice(basePackages={"org.my.pkg", "org.my.other.pkg"})}.     * 
{
    @link #value} is an alias for this attribute, simply allowing for     * more concise use of the annotation.     * 
Also consider using {
    @link #basePackageClasses()} as a type-safe     * alternative to String-based package names.     * @since 4.0     */    @AliasFor("value")    String[] basePackages() default {};    /**     * Type-safe alternative to {
    @link #value()} for specifying the packages     * to select Controllers to be assisted by the {
    @code @ControllerAdvice}     * annotated class.     * 
Consider creating a special no-op marker class or interface in each package     * that serves no purpose other than being referenced by this attribute.     * @since 4.0     */    Class
      [] basePackageClasses() default {};    /**     * Array of classes.     * 
Controllers that are assignable to at least one of the given types     * will be assisted by the {
    @code @ControllerAdvice} annotated class.     * @since 4.0     */    Class
      [] assignableTypes() default {};    /**     * Array of annotations.     * 
Controllers that are annotated with this/one of those annotation(s)     * will be assisted by the {
    @code @ControllerAdvice} annotated class.     * 
Consider creating a special annotation or use a predefined one,     * like {
    @link RestController @RestController}.     * @since 4.0     */    Class
      [] annotations() default {};}

和此注解配合使用的其他注解有：

1. @ExceptionHandler   自定义的错误处理器
2. @ModelAttribute      全局的对所有的controller的Model添加属性
3. @InitBinder  对表单数据绑定

 

下面给一个例子：

import java.io.IOException;import java.io.PrintWriter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.commons.lang.StringUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.ControllerAdvice;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.ModelAttribute;import com.gongren.dlg.activity.exception.NoSessionException;/** * springMVC的ControllerAdvice   * * @author yzl * @see [相关类/方法]（可选） * @since [产品/模块版本] （可选） */@ControllerAdvicepublic class WebContextAdvice {    private static final Logger logger = LoggerFactory.getLogger(WebContextAdvice.class);        /**     *      * 功能描述: 
     * 应用上下文设值给Model对象     * 在jsp中使用:${ctx}     *     * @param request     * @return     * @see [相关类/方法](可选)     * @since [产品/模块版本](可选)     */    @ModelAttribute(value="ctx")    public String setContextPath(HttpServletRequest request){        return request.getContextPath();    }        /**     *      * 错误处理器     *     * @param e     * @return     * @see [相关类/方法](可选)     * @since [产品/模块版本](可选)     */    @ExceptionHandler    public String handleIOException(HttpServletRequest request,HttpServletResponse response,Model model,Exception e) {        //请求类型,可以区分对待ajax和普通请求        String requestType = request.getHeader("X-Requested-With");        if(StringUtils.isNotBlank(requestType)){            //是ajax            try {                response.setCharacterEncoding("UTF-8");                  response.setContentType("application/json; charset=utf-8");                                  PrintWriter writer = response.getWriter();                //具体操作                writer.write("json...");                //                writer.flush();                writer.close();                return null;            } catch (IOException e1) {            }        }        if(e instanceof NoSessionException){            logger.error("session超时，跳转到活动首页");            return "redirect:/mc/index";        }        logger.error("请求发生错误", e);        return "redirect:/mc/error";    }}