SpringMVC09异常处理和类型转化器详解编程语言

 1 public class User { 
 2  
 3     private String name; 
 4     private Integer age; 
 5  
 6     public String getName() { 
 7         return name; 
 8     } 
 9  
10     public void setName(String name) { 
11         this.name = name; 
12     } 
13  
14     public Integer getAge() { 
15         return age; 
16     } 
17  
18     public void setAge(Integer age) { 
19         this.age = age; 
20     } 
21  
22     public User(String name, Integer age) { 
23         super(); 
24         this.name = name; 
25         this.age = age; 
26     } 
27  
28     public User() { 
29         super(); 
30     } 
31  
32     @Override 
33     public String toString() { 
34         return "User [name=" + name + ", age=" + age + "]"; 
35     } 
36  
37 }

user实体类

public class User { 
 
    private String name; 
    private Integer age; 
 
    public String getName() { 
        return name; 
    } 
 
    public void setName(String name) { 
        this.name = name; 
    } 
 
    public Integer getAge() { 
        return age; 
    } 
 
    public void setAge(Integer age) { 
        this.age = age; 
    } 
 
    public User(String name, Integer age) { 
        super(); 
        this.name = name; 
        this.age = age; 
    } 
 
    public User() { 
        super(); 
    } 
 
    @Override 
    public String toString() { 
        return "User [name=" + name + ", age=" + age + "]"; 
    } 
 
}

对应的异常处理类

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

User异常类

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

name异常类

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

age异常类

@Controller 
@RequestMapping("/user") 
public class MyController { 
    /** 
     * 跳转到/list 
     * Model:跳转list方法时 携带的数据 
     * @throws UserException  
     */ 
    @RequestMapping(value = "/add") 
    public String add(User user, Model mv) throws UserException { 
        System.out.println("进入了add......"); 
        // 01.模拟异常 System.out.println(5 / 0); 
 
        // 02.模拟异常  name 
        if (!user.getName().equals("admin")) { 
            throw new NameException("用户名错误！"); 
        } 
        // 03.模拟异常 age 
        if (user.getAge() > 50) { 
            throw new AgeException("年龄不合法！"); 
        } 
 
        mv.addAttribute("name", user.getName()).addAttribute("age", 
                user.getAge()); 
        return "redirect:list"; 
    } 
 
    @RequestMapping(value = "/list") 
    public String list(User user) { 
        System.out.println("进入了list......"); 
        System.out.println(user.getName()); 
        System.out.println(user.getAge()); 
        return "/success.jsp"; 
    } 
 
}

对应的controller代码

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation=" 
        http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd 
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 
 
 
<!-- 配置需要扫描的包 --> 
<context:component-scan base-package="cn.bdqn.controller"/> 
<!-- 开启注解 --> 
<mvc:annotation-driven/> 
 
<!-- 设置异常处理 --> 
<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver"> 
   <!-- 01.出现异常时 跳转的界面--> 
    <property name="defaultErrorView" value="/errors/error.jsp"/> 
    <!-- 02.给用户提示信息 --> 
    <property name="exceptionAttribute" value="ex"/> 
    <!-- 03.自定义的异常跳转界面  --> 
    <property name="exceptionMappings"> 
     <props> 
       <prop key="cn.bdqn.exception.NameException">/errors/nameError.jsp</prop> 
       <prop key="cn.bdqn.exception.AgeException">/errors/ageError.jsp</prop> 
     </props> 
      
    </property> 
</bean>

springmvc-servlet.xml文件

需要的界面

  <body> 
  <form action="user/add" method="post"> 
  <!-- 必须是User类中对应的属性名 --> 
    用户名：<input type="text"  name="name"> 
     年龄：<input type="text"  name="age"> 
  <button type="submit">提交</button> 
  </form> 
   
  </body>

index.jsp

  <body> 
   <h1>错误界面</h1> 
   ${ex.message} 
  </body>

error.jsp

  <body> 
   <h1>name错误界面</h1> 
   ${ex.message} 
  </body>

nameError.jsp

  <body> 
   <h1>age错误界面</h1> 
   ${ex.message} 
  </body>

ageError.jsp

====================自定义异常处理器===========================

/** 
 * 自定义的异常处理器  implements HandlerExceptionResolver 
 */ 
public class MyExceptionResolver implements HandlerExceptionResolver { 
    /** 
     * handler:就是我们的controller 
     * ex:controller出现的异常信息 
     */ 
    public ModelAndView resolveException(HttpServletRequest request, 
            HttpServletResponse response, Object handler, Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
        mv.setViewName("/errors/error.jsp"); // 其他异常处理 
        if (ex instanceof NameException) { 
            mv.setViewName("/errors/nameError.jsp"); 
        } 
        if (ex instanceof AgeException) { 
            mv.setViewName("/errors/ageError.jsp"); 
        } 
        return mv; 
    } 
 
}

创建自定义的异常处理器

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation=" 
        http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd 
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 
 
 
<!-- 配置需要扫描的包 --> 
<context:component-scan base-package="cn.bdqn.controller"/> 
<!-- 开启注解 --> 
<mvc:annotation-driven/> 
 
<!-- 设置自定义的异常处理器--> 
<bean class="cn.bdqn.controller.MyExceptionResolver"/> 
 
 
 
</beans>

修改springmvc-servlet.xml

其他代码不需要更改！测试即可！

===================使用注解的方式实现异常处理=======================

删除上个例子中xml文件配置的自定义异常处理器

/** 
 *03.提取出来一个处理异常的类 
 */ 
@Controller 
public class BaseController { // 专门来处理 异常的 
 
    @ExceptionHandler 
    // 其他的异常 
    public ModelAndView defaultException(Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
        mv.setViewName("/errors/error.jsp"); // 其他异常处理 
        return mv; 
    } 
 
    @ExceptionHandler(NameException.class) 
    // name的异常 
    public ModelAndView nameException(Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
        mv.setViewName("/errors/nameError.jsp"); 
        return mv; 
    } 
 
    @ExceptionHandler(AgeException.class) 
    // age的异常 
    public ModelAndView ageException(Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
 
        mv.setViewName("/errors/ageError.jsp"); 
        return mv; 
    } 
}

BaseController

@Controller 
@RequestMapping("/user") 
public class MyController extends BaseController { 
    /** 
     * 跳转到/list 
     * Model:跳转list方法时 携带的数据 
     * @throws UserException  
     */ 
    @RequestMapping(value = "/add") 
    public String add(User user, Model mv) throws UserException { 
        System.out.println("进入了add......"); 
        // 01.模拟异常 
        // System.out.println(5 / 0); 
 
        // 02.模拟异常 name 
        if (!user.getName().equals("admin")) { 
            throw new NameException("用户名错误！"); 
        } 
        // 03.模拟异常 age 
        if (user.getAge() > 50) { 
            throw new AgeException("年龄不合法！"); 
        } 
 
        mv.addAttribute("name", user.getName()).addAttribute("age", 
                user.getAge()); 
        return "redirect:list"; 
    } 
 
    @RequestMapping(value = "/list") 
    public String list(User user) { 
        System.out.println("进入了list......"); 
        System.out.println(user.getName()); 
        System.out.println(user.getAge()); 
        return "/success.jsp"; 
    } 
 
    /** 
     * 01.所有的异常的都在一个方法中 处理 
      
    @ExceptionHandler 
    public ModelAndView resolveException(Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
        mv.setViewName("/errors/error.jsp"); // 其他异常处理 
        if (ex instanceof NameException) { 
             
            mv.setViewName("/errors/nameError.jsp"); 
        } 
        if (ex instanceof AgeException) { 
             
            mv.setViewName("/errors/ageError.jsp"); 
        } 
        return mv; 
    }*/ 
 
    /** 
     * 02.针对于每个异常 
     
    @ExceptionHandler 
    // 其他的异常 
    public ModelAndView defaultException(Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
        mv.setViewName("/errors/error.jsp"); // 其他异常处理 
        return mv; 
    } 
 
    @ExceptionHandler(NameException.class) 
    // name的异常 
    public ModelAndView nameException(Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
        mv.setViewName("/errors/nameError.jsp"); 
        return mv; 
    } 
 
    @ExceptionHandler(AgeException.class) 
    // age的异常 
    public ModelAndView ageException(Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("ex", ex);// 保存异常信息 
 
        mv.setViewName("/errors/ageError.jsp"); 
        return mv; 
    } */ 
}

Controller中的代码

==================类型转化器============================

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 
<% 
String path = request.getContextPath(); 
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 
%> 
 
<!DOCTYPE HTML> 
<html> 
  <head> 
    <base href="<%=basePath%>"> 
     
    <title>My JSP 'index.jsp' starting page</title> 
    <meta http-equiv="pragma" content="no-cache"> 
    <meta http-equiv="cache-control" content="no-cache"> 
    <meta http-equiv="expires" content="0">     
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 
    <meta http-equiv="description" content="This is my page"> 
    <!-- 
    <link rel="stylesheet" type="text/css" href="styles.css"> 
    --> 
  </head> 
  <body> 
  ${ex.message} 
  <form action="user/login" method="post"> 
  <!-- 必须是User类中对应的属性名 --> 
    出生日期：<input type="text"  name="birthday" value="${birthday}"> ${birthdayError}<br/> 
     年龄：<input type="text"  name="age" value="${age}"> ${ageError} 
  <button type="submit">提交</button> 
  </form> 
   
  </body> 
</html>

index.jsp页面

@Controller 
@RequestMapping("/user") 
public class MyController { 
    /** 
     * 登录 
     * Date  能自动类型转换        2015/    02/02 
     */ 
    @RequestMapping(value = "/login") 
    public ModelAndView login(int age, Date birthday) { 
        System.out.println("进入了login......"); 
        System.out.println(age); 
        System.out.println(birthday); 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("age", age).addObject("birthday", birthday) 
                .setViewName("/success.jsp"); 
        return mv; 
    } 
 
    /** 
     * TypeMismatchException 类型转换不了的时候  抛出的异常 
     * HttpServletRequest request:数据的回显 
     * Exception ex：给用户提示 
     */ 
    @ExceptionHandler(TypeMismatchException.class) 
    public ModelAndView exceptionAge(HttpServletRequest request, Exception ex) { 
        ModelAndView mv = new ModelAndView(); 
        String age = request.getParameter("age"); 
        String birthday = request.getParameter("birthday"); 
        // 让用户看到错误的信息 
        String message = ex.getMessage(); 
        if (message.contains(age)) { 
            mv.addObject("ageError", "年龄输入有误！"); 
        } 
        if (message.contains(birthday)) { 
            mv.addObject("birthdayError", "日期输入有误！"); 
        } 
 
        mv.addObject("age", age).addObject("birthday", birthday) 
                .addObject("ex", ex).setViewName("/index.jsp"); 
 
        return mv; 
    } 
 
}

Controller

/** 
 *  
 * 自定义的类型转化器 
 *  @param <S> the source type  前台表单中肯定是string 
 * @param <T> the target type 
 * 
 * public interface Converter<S, T> { 
 */ 
public class MyDateConverter implements Converter<String, Date> { 
    /** 
     * source：前台传递来的字符串 
     */ 
    public Date convert(String source) { 
        // 类型转化 
        SimpleDateFormat sdf = getDate(source); 
        Date parse = null; 
        try { 
            parse = sdf.parse(source); 
        } catch (ParseException e) { 
            e.printStackTrace(); 
        } 
        return parse; 
    } 
 
    /** 
     * @param source 传递来的日期格式的字符串 
     *  
     */ 
    private SimpleDateFormat getDate(String source) { 
        SimpleDateFormat sdf = new SimpleDateFormat(); 
        // 判断 
        if (Pattern.matches("^//d{4}-//d{2}-//d{2}$", source)) { 
            sdf = new SimpleDateFormat("yyyy-MM-dd"); 
        } else if (Pattern.matches("^//d{4}///d{2}///d{2}$", source)) { 
            sdf = new SimpleDateFormat("yyyy/MM/dd"); 
        } else if (Pattern.matches("^//d{4}//d{2}//d{2}$", source)) { 
            sdf = new SimpleDateFormat("yyyyMMdd"); 
        } else { 
            /** 
             * 都不匹配了   就让它抛出 TypeMismatchException异常 
             *     public TypeMismatchException(Object value, Class<?> requiredType) { 
             * vallue 值能对应requiredType 类型 就不会出现异常 
             *  我们就得写一个不能转换的 
             */ 
            throw new TypeMismatchException("", Date.class); 
        } 
        return sdf; 
    } 
}

类型转化器代码

public class User { 
 
    private String name; 
    private Date birthday; 
    private Integer age; 
 
    public String getName() { 
        return name; 
    } 
 
    public void setName(String name) { 
        this.name = name; 
    } 
 
    public Integer getAge() { 
        return age; 
    } 
 
    public void setAge(Integer age) { 
        this.age = age; 
    } 
 
    @Override 
    public String toString() { 
        return "User [name=" + name + ", birthday=" + birthday + ", age=" + age 
                + "]"; 
    } 
 
    public User(String name, Date birthday, Integer age) { 
        super(); 
        this.name = name; 
        this.birthday = birthday; 
        this.age = age; 
    } 
 
    public Date getBirthday() { 
        return birthday; 
    } 
 
    public void setBirthday(Date birthday) { 
        this.birthday = birthday; 
    } 
 
    public User() { 
        super(); 
    } 
 
}

需要的User实体类

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation=" 
        http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd 
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 
 
 
<!-- 配置需要扫描的包 --> 
<context:component-scan base-package="cn.bdqn.controller"/> 
<!-- 开启注解 --> 
<mvc:annotation-driven conversion-service="conversionService"/> 
<!-- 注册我们自己创建的类型转换器  --> 
<bean  id="myDateConverter" class="cn.bdqn.controller.MyDateConverter"/> 
 
<!-- 创建一个类型转换器工厂 来加载我们自己创建的类型转换器  --> 
<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean"> 
   <property name="converters"> 
     <set> 
      <ref bean="myDateConverter"/><!--如果需要配置多个类型转化器  只需要增加 ref节点 --> 
     </set> 
   </property> 
 
</bean> 
 
 
</beans>

springmvc-servlet.xml文件

  <body> 
  <h1>webroot   success页面</h1> 
  ${birthday}<br/> 
  ${age} 
  </body>

success.jsp页面

======================初始化类型绑定===================

在上面的例子中修改xml文件内容! 也就是把之前的类型转换器删掉

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation=" 
        http://www.springframework.org/schema/beans  
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd 
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 
 
 
<!-- 配置需要扫描的包 --> 
<context:component-scan base-package="cn.bdqn.controller"/> 
<!-- 开启注解 --> 
<mvc:annotation-driven/> 
 
 
 
</beans>

springmvc-servlet.xml文件内容

修改controller中的代码

@Controller 
@RequestMapping("/user") 
public class MyController { 
    /** 
     * 登录 
     * Date  能自动类型转换        2015/    02/02 
     */ 
    @RequestMapping(value = "/login") 
    public ModelAndView login(int age, Date birthday) { 
        System.out.println("进入了login......"); 
        System.out.println(age); 
        System.out.println(birthday); 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("age", age).addObject("birthday", birthday) 
                .setViewName("/success.jsp"); 
        return mv; 
    } 
 
    /** 
     * 初始化参数的绑定 
     * binder.registerCustomEditor(Date.class, new CustomDateEditor(df, true)) 
     * Date.class:需要转换成的类型 
     * new CustomDateEditor：类型编辑器 
     * true代表 允许日期格式为空 
     */ 
    @InitBinder 
    public void initBinder(WebDataBinder binder) { 
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); // 只能匹配这种格式 
        binder.registerCustomEditor(Date.class, new CustomDateEditor(df, true)); 
    } 
}

匹配一种日期格式的controller

之后可以运行测试！

创建自己定义的类型编辑器来完成多种日期格式的绑定

/** 
 *  
 * 自定义的类型编辑器 
 */ 
public class MyDateEditor extends PropertiesEditor { 
    @Override 
    public void setAsText(String source) throws IllegalArgumentException { 
        SimpleDateFormat sdf = getDate(source); 
        Date parse = null; 
        // 类型转化 
        try { 
            parse = sdf.parse(source); 
            setValue(parse); 
        } catch (ParseException e) { 
            e.printStackTrace(); 
        } 
    } 
 
    /** 
     * @param source 传递来的日期格式的字符串 
     *  
     */ 
    private SimpleDateFormat getDate(String source) { 
        SimpleDateFormat sdf = new SimpleDateFormat(); 
        // 判断 
        if (Pattern.matches("^//d{4}-//d{2}-//d{2}$", source)) { 
            sdf = new SimpleDateFormat("yyyy-MM-dd"); 
        } else if (Pattern.matches("^//d{4}///d{2}///d{2}$", source)) { 
            sdf = new SimpleDateFormat("yyyy/MM/dd"); 
        } else if (Pattern.matches("^//d{4}//d{2}//d{2}$", source)) { 
            sdf = new SimpleDateFormat("yyyyMMdd"); 
        } else { 
            /** 
             * 都不匹配了   就让它抛出 TypeMismatchException异常 
             *     public TypeMismatchException(Object value, Class<?> requiredType) { 
             * vallue 值能对应requiredType 类型 就不会出现异常 
             *  我们就得写一个不能转换的 
             */ 
            throw new TypeMismatchException("", Date.class); 
        } 
        return sdf; 
    } 
}

MyDateEditor

修改controller中的代码

package cn.bdqn.controller; 
 
import java.util.Date; 
 
import org.springframework.stereotype.Controller; 
import org.springframework.web.bind.WebDataBinder; 
import org.springframework.web.bind.annotation.InitBinder; 
import org.springframework.web.bind.annotation.RequestMapping; 
import org.springframework.web.servlet.ModelAndView; 
 
@Controller 
@RequestMapping("/user") 
public class MyController { 
    /** 
     * 登录 
     * Date  能自动类型转换        2015/    02/02 
     */ 
    @RequestMapping(value = "/login") 
    public ModelAndView login(int age, Date birthday) { 
        System.out.println("进入了login......"); 
        System.out.println(age); 
        System.out.println(birthday); 
        ModelAndView mv = new ModelAndView(); 
        mv.addObject("age", age).addObject("birthday", birthday) 
                .setViewName("/success.jsp"); 
        return mv; 
    } 
 
    /** 
     * 初始化参数的绑定 
     * binder.registerCustomEditor(Date.class, new CustomDateEditor(df, true)) 
     * Date.class:需要转换成的类型 
     * new CustomDateEditor：类型编辑器 
     * true代表 允许日期格式为空 
      
    @InitBinder 
    public void initBinder(WebDataBinder binder) { 
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); // 只能匹配这种格式 
        binder.registerCustomEditor(Date.class, new CustomDateEditor(df, true)); 
    }*/ 
 
    /** 
     * 绑定多种日期格式 
     */ 
    @InitBinder 
    public void initBinder(WebDataBinder binder) { 
        // 使用自己定义的类型编辑器new MyDateEditor() 
        binder.registerCustomEditor(Date.class, new MyDateEditor()); 
    } 
}

Controller代码

其他代码不动测试即可！

原创文章，作者：奋斗，如若转载，请注明出处：https://blog.ytso.com/12161.html

SpringMVC09异常处理和类型转化器详解编程语言

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