5.全局异常捕捉【从零开始学Spring Boot】

时间：2023-03-08 16:45:13

在一个项目中的异常我们我们都会统一进行处理的，那么如何进行统一进行处理呢？

新建一个类GlobalDefaultExceptionHandler，

在class注解上@ControllerAdvice,

在方法上注解上@ExceptionHandler(value= Exception.class)，具体代码如下：

com.kfit.base.exception.GlobalDefaultExceptionHandler

packagecom.kfit.base.exception;

importjavax.servlet.http.HttpServletRequest;

importorg.springframework.web.bind.annotation.ControllerAdvice;

import org.springframework.web.bind.annotation.ExceptionHandler;

@ControllerAdvice

public class GlobalDefaultExceptionHandler{

@ExceptionHandler(value = Exception.class)

public voiddefaultErrorHandler(HttpServletRequest req, Exception e) {

//      // If the exception is annotatedwith @ResponseStatus rethrow it and let

//      // the framework handle it -like the OrderNotFoundException example

//      // at the start of thispost.

//      // AnnotationUtils is aSpring Framework utility class.

//      if (AnnotationUtils.findAnnotation(e.getClass(),ResponseStatus.class) != null)

//          throw e;

//

//      // Otherwise setup and sendthe user to a default error-view.

//      ModelAndView mav =new ModelAndView();

//     mav.addObject("exception", e);

//      mav.addObject("url",req.getRequestURL());

//     mav.setViewName(DEFAULT_ERROR_VIEW);

//      return mav;

//打印异常信息：

e.printStackTrace();

System.out.println("GlobalDefaultExceptionHandler.defaultErrorHandler()");

/*

* 返回json数据或者String数据：

* 那么需要在方法上加上注解：@ResponseBody

* 添加return即可。

*/

/*

* 返回视图：

* 定义一个ModelAndView即可，

* 然后return;

* 定义视图文件(比如：error.html,error.ftl,error.jsp);

*

*/

}

}

com.kfit.test.web.DemoController 加入方法：

@RequestMapping("/zeroException")

public int zeroException(){

return 100/0;

}

访问：http://127.0.0.1:8080/zeroException这个方法肯定是抛出异常的,那么在控制台就可以看到我们全局捕捉的异常信息了。

更精确的异常捕捉：

@Controller
public class ExceptionHandlingController {
 
  // @RequestHandler methods
  ...
  
  // Exception handling methods
  
  // Convert a predefined exception to an HTTP Status code
  @ResponseStatus(value=HttpStatus.CONFLICT, reason="Data integrity violation")  // 409
  @ExceptionHandler(DataIntegrityViolationException.class)
  public void conflict() {
    // Nothing to do
  }
  
  // Specify the name of a specific view that will be used to display the error:
  @ExceptionHandler({SQLException.class,DataAccessException.class})
  public String databaseError() {
    // Nothing to do.  Returns the logical view name of an error page, passed to
    // the view-resolver(s) in usual way.
    // Note that the exception is _not_ available to this view (it is not added to
    // the model) but see "Extending ExceptionHandlerExceptionResolver" below.
    return "databaseError";
  }
 
  // Total control - setup a model and return the view name yourself. Or consider
  // subclassing ExceptionHandlerExceptionResolver (see below).
  @ExceptionHandler(Exception.class)
  public ModelAndView handleError(HttpServletRequest req, Exception exception) {
    logger.error("Request: " + req.getRequestURL() + " raised " + exception);
 
    ModelAndView mav = new ModelAndView();
    mav.addObject("exception", exception);
    mav.addObject("url", req.getRequestURL());
    mav.setViewName("error");
    return mav;
  }
}

问题描述： 
在使用spring的jdbcTemplate的时候，提示Caused by: java.lang.ClassNotFoundException: org.springframework.dao.DataAccessException错误。 
解决方法：
POM 引入
<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>