重新学习SpringMVC——高级

30. SpringMVC_RESTRUL_CRUD_显示所有员工信息
31. SpringMVC_RESTRUL_CRUD_添加操作&表单标签
32. SpringMVC_RESTRUL_CRUD_删除操作&处理静态资源
33. SpringMVC_RESTRUL_CRUD_修改操作
34. SpringMVC_数据绑定流程分析
35. SpringMVC_自定义类型转换器
36. SpringMVC_annotation-driven配置
37. SpringMVC_InitBinder注解
38. SpringMVC_数据的格式化
39. SpringMVC_JSR303数据校验
40. SpringMVC_错误消息的显示及国际化
41. SpringMVC_返回JSON
42. SpringMVC_HttpMessageConverter原理
43. SpringMVC_使用HttpMessageConverter
44. SpringMVC_国际化_概述
45. SpringMVC_国际化_前两个问题
46. SpringMVC_国际化_通过超链接切换Locale
47. SpringMVC_文件上传
48. SpringMVC_第一个自定义的拦截器
49. SpringMVC_拦截器的配置
50. SpringMVC_多个拦截方法的执行顺序
51. SpringMVC_异常处理_ExceptionHandler注解
52. SpringMVC_异常处理_ResponseStatusExceptionResolver
53. SpringMVC_异常处理_DefaultHandlerExceptionResolver
54. SpringMVC_异常处理_SimpleMappingExceptionResolver
55. SpringMVC_运行流程图解

 springmvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">

    <!-- 配置自动扫描的包 -->
    <context:component-scan base-package="com.atguigu.springmvc"></context:component-scan>

    <!-- 配置视图解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    
    <!--  
        default-servlet-handler 将在 SpringMVC 上下文中定义一个 DefaultServletHttpRequestHandler,
        它会对进入 DispatcherServlet 的请求进行筛查, 如果发现是没有经过映射的请求, 就将该请求交由 WEB 应用服务器默认的 
        Servlet 处理. 如果不是静态资源的请求，才由 DispatcherServlet 继续处理

        一般 WEB 应用服务器默认的 Servlet 的名称都是 default.
        若所使用的 WEB 服务器的默认 Servlet 名称不是 default，则需要通过 default-servlet-name 属性显式指定
        
    -->
    <mvc:default-servlet-handler/>

    <mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven>    
    
    <!-- 配置 ConversionService -->
    <bean id="conversionService"
        class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <ref bean="employeeConverter"/>
            </set>
        </property>    
    </bean>
    
    <!-- 配置国际化资源文件 -->
    <bean id="messageSource"
        class="org.springframework.context.support.ResourceBundleMessageSource">
        <property name="basename" value="i18n"></property>
    </bean>
    
    <!-- 配置 SessionLocalResolver -->
    <bean id="localeResolver"
        class="org.springframework.web.servlet.i18n.SessionLocaleResolver"></bean>
    
    <mvc:interceptors>
        <!-- 配置自定义的拦截器 -->
        <bean class="com.atguigu.springmvc.interceptors.FirstInterceptor"></bean>
        
        <!-- 配置拦截器(不)作用的路径 -->
        <mvc:interceptor>
            <mvc:mapping path="/emps"/>
            <bean class="com.atguigu.springmvc.interceptors.SecondInterceptor"></bean>
        </mvc:interceptor>
        
        <!-- 配置 LocaleChanceInterceptor -->
        <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"></bean>
    </mvc:interceptors>
    
    <!--  
    <mvc:view-controller path="/i18n" view-name="i18n"/>
    -->
    <mvc:view-controller path="/i18n2" view-name="i18n2"/>
    
    <!-- 配置 MultipartResolver -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="defaultEncoding" value="UTF-8"></property>
        <property name="maxUploadSize" value="1024000"></property>    
    </bean>    
    
    <!-- 配置使用 SimpleMappingExceptionResolver 来映射异常 -->
    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <property name="exceptionAttribute" value="ex"></property>
        <property name="exceptionMappings">
            <props>
                <prop key="java.lang.ArrayIndexOutOfBoundsException">error</prop>
            </props>
        </property>
    </bean>    
        
</beans>

EmployeeHandler.Java

@Controller
public class EmployeeHandler {

    @Autowired
    private EmployeeDao employeeDao;
    
    @Autowired
    private DepartmentDao departmentDao;

    @ModelAttribute
    public void getEmployee(@RequestParam(value="id",required=false) Integer id,
            Map<String, Object> map){
        if(id != null){
            map.put("employee", employeeDao.get(id));
        }
    }
    
    @RequestMapping(value="/emp", method=RequestMethod.PUT)
    public String update(Employee employee){
        employeeDao.save(employee);
        
        return "redirect:/emps";
    }
    
    @RequestMapping(value="/emp/{id}", method=RequestMethod.GET)
    public String input(@PathVariable("id") Integer id, Map<String, Object> map){
        map.put("employee", employeeDao.get(id));
        map.put("departments", departmentDao.getDepartments());
        return "input";
    }
    
    @RequestMapping(value="/emp/{id}", method=RequestMethod.DELETE)
    public String delete(@PathVariable("id") Integer id){
        employeeDao.delete(id);
        return "redirect:/emps";
    }
    
    @RequestMapping(value="/emp", method=RequestMethod.POST)
    public String save(@Valid Employee employee, Errors result, 
            Map<String, Object> map){
        System.out.println("save: " + employee);
        
        if(result.getErrorCount() > 0){
            System.out.println("出错了!");
            
            for(FieldError error:result.getFieldErrors()){
                System.out.println(error.getField() + ":" + error.getDefaultMessage());
            }
            
            //若验证出错, 则转向定制的页面
            map.put("departments", departmentDao.getDepartments());
            return "input";
        }
        
        employeeDao.save(employee);
        return "redirect:/emps";
    }
    
    @RequestMapping(value="/emp", method=RequestMethod.GET)
    public String input(Map<String, Object> map){
        map.put("departments", departmentDao.getDepartments());
        map.put("employee", new Employee());
        return "input";
    }
    
    @RequestMapping("/emps")
    public String list(Map<String, Object> map){
        map.put("employees", employeeDao.getAll());
        return "list";
    }
    
//    @InitBinder
//    public void initBinder(WebDataBinder binder){
//        binder.setDisallowedFields("lastName");
//    }
    
}

SpringMVCTest.java

@Controller
public class SpringMVCTest {

    @Autowired
    private EmployeeDao employeeDao;
    
    @Autowired
    private ResourceBundleMessageSource messageSource;
    
    @RequestMapping("/testSimpleMappingExceptionResolver")
    public String testSimpleMappingExceptionResolver(@RequestParam("i") int i){
        String [] vals = new String[10];
        System.out.println(vals[i]);
        return "success";
    }
    
    @RequestMapping(value="/testDefaultHandlerExceptionResolver",method=RequestMethod.POST)
    public String testDefaultHandlerExceptionResolver(){
        System.out.println("testDefaultHandlerExceptionResolver...");
        return "success";
    }
    
    @ResponseStatus(reason="测试",value=HttpStatus.NOT_FOUND)
    @RequestMapping("/testResponseStatusExceptionResolver")
    public String testResponseStatusExceptionResolver(@RequestParam("i") int i){
        if(i == 13){
            throw new UserNameNotMatchPasswordException();
        }
        System.out.println("testResponseStatusExceptionResolver...");
        
        return "success";
    }
    
//    @ExceptionHandler({RuntimeException.class})
//    public ModelAndView handleArithmeticException2(Exception ex){
//        System.out.println("[出异常了]: " + ex);
//        ModelAndView mv = new ModelAndView("error");
//        mv.addObject("exception", ex);
//        return mv;
//    }
    
    /**
     * 1. 在 @ExceptionHandler 方法的入参中可以加入 Exception 类型的参数, 该参数即对应发生的异常对象
     * 2. @ExceptionHandler 方法的入参中不能传入 Map. 若希望把异常信息传导页面上, 需要使用 ModelAndView 作为返回值
     * 3. @ExceptionHandler 方法标记的异常有优先级的问题. 
     * 4. @ControllerAdvice: 如果在当前 Handler 中找不到 @ExceptionHandler 方法来出来当前方法出现的异常, 
     * 则将去 @ControllerAdvice 标记的类中查找 @ExceptionHandler 标记的方法来处理异常. 
     */
//    @ExceptionHandler({ArithmeticException.class})
//    public ModelAndView handleArithmeticException(Exception ex){
//        System.out.println("出异常了: " + ex);
//        ModelAndView mv = new ModelAndView("error");
//        mv.addObject("exception", ex);
//        return mv;
//    }
    
    @RequestMapping("/testExceptionHandlerExceptionResolver")
    public String testExceptionHandlerExceptionResolver(@RequestParam("i") int i){
        System.out.println("result: " + (10 / i));
        return "success";
    }
    
    @RequestMapping("/testFileUpload")
    public String testFileUpload(@RequestParam("desc") String desc, 
            @RequestParam("file") MultipartFile file) throws IOException{
        System.out.println("desc: " + desc);
        System.out.println("OriginalFilename: " + file.getOriginalFilename());
        System.out.println("InputStream: " + file.getInputStream());
        return "success";
    }
    
    @RequestMapping("/i18n")
    public String testI18n(Locale locale){
        String val = messageSource.getMessage("i18n.user", null, locale);
        System.out.println(val); 
        return "i18n";
    }
    
    @RequestMapping("/testResponseEntity")
    public ResponseEntity<byte[]> testResponseEntity(HttpSession session) throws IOException{
        byte [] body = null;
        ServletContext servletContext = session.getServletContext();
        InputStream in = servletContext.getResourceAsStream("/files/abc.txt");
        body = new byte[in.available()];
        in.read(body);
        
        HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Disposition", "attachment;filename=abc.txt");
        
        HttpStatus statusCode = HttpStatus.OK;
        
        ResponseEntity<byte[]> response = new ResponseEntity<byte[]>(body, headers, statusCode);
        return response;
    }
    
    @ResponseBody
    @RequestMapping("/testHttpMessageConverter")
    public String testHttpMessageConverter(@RequestBody String body){
        System.out.println(body);
        return "helloworld! " + new Date();
    }
    
    @ResponseBody
    @RequestMapping("/testJson")
    public Collection<Employee> testJson(){
        return employeeDao.getAll();
    }
    
    @RequestMapping("/testConversionServiceConverer")
    public String testConverter(@RequestParam("employee") Employee employee){
        System.out.println("save: " + employee);
        employeeDao.save(employee);
        return "redirect:/emps";
    }
    
}