SpringMVC核心技术

目录

• 请求重定向和转发
• 请求转发
• 请求重定向
• 异常处理
• SpringMVC拦截器
• 拦截器过滤器的区别
• SpringMVC执行流程理解
• SpringMVC执行流程分析
• 总结

@RequestMapping(value = "/some",produces = "text/plain;charset=utf-8")
public ModelAndView testForward(String name,Integer age){
    ModelAndView mv = new ModelAndView();
    mv.addObject("name",name);
    mv.addObject("age",age);
    mv.setViewName("forward:/WEB-INF/view/show.jsp");
    return mv;
}

@RequestMapping(value = "/other")
public ModelAndView testRedirect(String name,Integer age){
    ModelAndView mv = new ModelAndView();
    mv.addObject("name",name);
    mv.addObject("age",age);
    mv.setViewName("redirect:/other.jsp");
    return mv;
}

public class MyException extends Exception {
    public MyException() {
        super();
    }
    public MyException(String message) {
        super(message);
    }
}

public class AgeException extends MyException {
    public AgeException() {
        super();
    }
    public AgeException(String message) {
        super(message);
    }
}
public class NameException extends MyException {
    public NameException() {
        super();
    }
    public NameException(String message) {
        super(message);
    }
}

@RequestMapping(value = "exception")
public ModelAndView askForException(String name,Integer age) throws MyException {
    ModelAndView mv = new ModelAndView();
    if(!"zs".equals(name)){
        throw new NameException("姓名不正确！！！");
    }
    if (age == null || age > 80){
        throw new AgeException("年龄太大了！！！");
    }
    mv.addObject("name",name);
    mv.addObject("age",age);
    mv.setViewName("show");
    return mv;

nameError.jsp


提示信息：${msg}


系统信息：${ex.message}
ageError.jsp


提示信息：${msg}


系统信息：${ex.message}
otherError.jsp


提示信息：${msg}


系统信息：${ex.message}

@ControllerAdvice
public class GlobalExceptionHandler {
    @ExceptionHandler(value = NameException.class)
    public ModelAndView nameException(Exception ex){
        ModelAndView mv = new ModelAndView();
        mv.addObject("msg","姓名不是zs");
        mv.addObject("ex",ex);
        mv.setViewName("nameError");
        return mv;
    }
    @ExceptionHandler(value = AgeException.class)
    public ModelAndView ageException(Exception ex){
        ModelAndView mv = new ModelAndView();
        mv.addObject("msg","年龄超过80岁啦");
        mv.addObject("ex",ex);
        mv.setViewName("ageError");
        return mv;
    }
    @ExceptionHandler
    public ModelAndView otherException(Exception ex){
        ModelAndView mv = new ModelAndView();
        mv.addObject("msg","未知异常");
        mv.addObject("ex",ex);
        mv.setViewName("otherError");
        return mv;
    }
}

public class myInterceptor implements HandlerInterceptor {
    private Long beginTime;
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle方法执行");
        beginTime = System.currentTimeMillis();
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle方法执行");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion方法执行");
        Long endTime = System.currentTimeMillis();
        System.out.println("程序执行时间" + (endTime - beginTime) + "ms");
    }
}