SpringMVC基础入门,创建一个HelloWorld程序
ref:http://www.admin10000.com/document/6436.html
一、SpringMVC基础入门,创建一个HelloWorld程序
1.首先,导入SpringMVC需要的jar包。
2.添加Web.xml配置文件中关于SpringMVC的配置
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<!--configure the setting of springmvcDispatcherServlet and configure the mapping--> < servlet > < servlet-name >springmvc</ servlet-name > < servlet-class >org.springframework.web.servlet.DispatcherServlet</ servlet-class > < init-param > < param-name >contextConfigLocation</ param-name > < param-value >classpath:springmvc-servlet.xml</ param-value > </ init-param > <!-- <load-on-startup>1</load-on-startup> --> </ servlet > < servlet-mapping > < servlet-name >springmvc</ servlet-name > < url-pattern >/</ url-pattern > </ servlet-mapping > |
3.在src下添加springmvc-servlet.xml配置文件
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<? xml version = "1.0" encoding = "UTF-8" ?> 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-4.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd"> <!-- scan the package and the sub package --> < context:component-scan base-package = "test.SpringMVC" /> <!-- don't handle the static resource --> < mvc:default-servlet-handler /> <!-- if you use annotation you must configure following setting --> < mvc:annotation-driven /> <!-- configure the InternalResourceViewResolver --> < bean class = "org.springframework.web.servlet.view.InternalResourceViewResolver" id = "internalResourceViewResolver" > <!-- 前缀 --> < property name = "prefix" value = "/WEB-INF/jsp/" /> <!-- 后缀 --> < property name = "suffix" value = ".jsp" /> </ bean > </ beans > |
4.在WEB-INF文件夹下创建名为jsp的文件夹,用来存放jsp视图。创建一个hello.jsp,在body中添加“Hello World”。
5.建立包及Controller,如下所示
6.编写Controller代码
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@Controller @RequestMapping ( "/mvc" ) public class mvcController { @RequestMapping ( "/hello" ) public String hello(){ return "hello" ; } } |
7.启动服务器,键入 http://localhost:8080/项目名/mvc/hello
二、配置解析
1.Dispatcherservlet
DispatcherServlet是前置控制器,配置在web.xml文件中的。拦截匹配的请求,Servlet拦截匹配规则要自已定义,把拦截下来的请求,依据相应的规则分发到目标Controller来处理,是配置spring MVC的第一步。
2.InternalResourceViewResolver
视图名称解析器
3.以上出现的注解
@Controller 负责注册一个bean 到spring 上下文中
@RequestMapping 注解为控制器指定可以处理哪些 URL 请求
三、SpringMVC常用注解
@Controller
负责注册一个bean 到spring 上下文中
@RequestMapping
注解为控制器指定可以处理哪些 URL 请求
@RequestBody
该注解用于读取Request请求的body部分数据,使用系统默认配置的HttpMessageConverter进行解析,然后把相应的数据绑定到要返回的对象上 ,再把HttpMessageConverter返回的对象数据绑定到 controller中方法的参数上
@ResponseBody
该注解用于将Controller的方法返回的对象,通过适当的HttpMessageConverter转换为指定格式后,写入到Response对象的body数据区
@ModelAttribute
在方法定义上使用 @ModelAttribute 注解:Spring MVC 在调用目标处理方法前,会先逐个调用在方法级上标注了@ModelAttribute 的方法
在方法的入参前使用 @ModelAttribute 注解:可以从隐含对象中获取隐含的模型数据中获取对象,再将请求参数 –绑定到对象中,再传入入参将方法入参对象添加到模型中
@RequestParam
在处理方法入参处使用 @RequestParam 可以把请求参 数传递给请求方法
@PathVariable
绑定 URL 占位符到入参
@ExceptionHandler
注解到方法上,出现异常时会执行该方法
@ControllerAdvice
使一个Contoller成为全局的异常处理类,类中用@ExceptionHandler方法注解的方法可以处理所有Controller发生的异常
四、自动匹配参数
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//match automatically @RequestMapping ( "/person" ) public String toPerson(String name, double age){ System.out.println(name+ " " +age); return "hello" ; } |
五、自动装箱
1.编写一个Person实体类
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package test.SpringMVC.model; public class Person { public String getName() { return name; } public void setName(String name) { this .name = name; } public int getAge() { return age; } public void setAge( int age) { this .age = age; } private String name; private int age; } |
2.在Controller里编写方法
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//boxing automatically @RequestMapping ( "/person1" ) public String toPerson(Person p){ System.out.println(p.getName()+ " " +p.getAge()); return "hello" ; } |
六、使用InitBinder来处理Date类型的参数
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//the parameter was converted in initBinder @RequestMapping ( "/date" ) public String date(Date date){ System.out.println(date); return "hello" ; } //At the time of initialization,convert the type "String" to type "date" @InitBinder public void initBinder(ServletRequestDataBinder binder){ binder.registerCustomEditor(Date. class , new CustomDateEditor( new SimpleDateFormat( "yyyy-MM-dd" ), true )); } |
七、向前台传递参数
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//pass the parameters to front-end @RequestMapping ( "/show" ) public String showPerson(Map<String,Object> map){ Person p = new Person(); map.put( "p" , p); p.setAge( 20 ); p.setName( "jayjay" ); return "show" ; } |
前台可在Request域中取到"p"
八、使用Ajax调用
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//pass the parameters to front-end using ajax @RequestMapping ( "/getPerson" ) public void getPerson(String name,PrintWriter pw){ pw.write( "hello," +name); } @RequestMapping ( "/name" ) public String sayHello(){ return "name" ; } |
前台用下面的Jquery代码调用
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$( function (){ $( "#btn" ).click( function (){ $.post( "mvc/getPerson" ,{name:$( "#name" ).val()}, function (data){ alert(data); }); }); }); |
九、在Controller中使用redirect方式处理请求
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//redirect @RequestMapping ( "/redirect" ) public String redirect(){ return "redirect:hello" ; } |
十、文件上传
1.需要导入两个jar包
2.在SpringMVC配置文件中加入
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<!-- upload settings --> < bean id = "multipartResolver" class = "org.springframework.web.multipart.commons.CommonsMultipartResolver" > < property name = "maxUploadSize" value = "102400000" ></ property > </ bean > |
3.方法代码
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@RequestMapping (value= "/upload" ,method=RequestMethod.POST) public String upload(HttpServletRequest req) throws Exception{ MultipartHttpServletRequest mreq = (MultipartHttpServletRequest)req; MultipartFile file = mreq.getFile( "file" ); String fileName = file.getOriginalFilename(); SimpleDateFormat sdf = new SimpleDateFormat( "yyyyMMddHHmmss" ); FileOutputStream fos = new FileOutputStream(req.getSession().getServletContext().getRealPath( "/" )+ "upload/" +sdf.format( new Date())+fileName.substring(fileName.lastIndexOf( '.' ))); fos.write(file.getBytes()); fos.flush(); fos.close(); return "hello" ; } |
4.前台form表单
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< form action = "mvc/upload" method = "post" enctype = "multipart/form-data" > < input type = "file" name = "file" >< br > < input type = "submit" value = "submit" > </ form > |
十一、使用@RequestParam注解指定参数的name
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@Controller @RequestMapping ( "/test" ) public class mvcController1 { @RequestMapping (value= "/param" ) public String testRequestParam( @RequestParam (value= "id" ) Integer id, @RequestParam (value= "name" )String name){ System.out.println(id+ " " +name); return "/hello" ; } } |
十二、RESTFul风格的SringMVC
1.RestController
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@Controller @RequestMapping ( "/rest" ) public class RestController { @RequestMapping (value= "/user/{id}" ,method=RequestMethod.GET) public String get( @PathVariable ( "id" ) Integer id){ System.out.println( "get" +id); return "/hello" ; } @RequestMapping (value= "/user/{id}" ,method=RequestMethod.POST) public String post( @PathVariable ( "id" ) Integer id){ System.out.println( "post" +id); return "/hello" ; } @RequestMapping (value= "/user/{id}" ,method=RequestMethod.PUT) public String put( @PathVariable ( "id" ) Integer id){ System.out.println( "put" +id); return "/hello" ; } @RequestMapping (value= "/user/{id}" ,method=RequestMethod.DELETE) public String delete( @PathVariable ( "id" ) Integer id){ System.out.println( "delete" +id); return "/hello" ; } } |
2.form表单发送put和delete请求
在web.xml中配置
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<!-- configure the HiddenHttpMethodFilter,convert the post method to put or delete --> < filter > < filter-name >HiddenHttpMethodFilter</ filter-name > < filter-class >org.springframework.web.filter.HiddenHttpMethodFilter</ filter-class > </ filter > < filter-mapping > < filter-name >HiddenHttpMethodFilter</ filter-name > < url-pattern >/*</ url-pattern > </ filter-mapping > |
在前台可以用以下代码产生请求
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< form action = "rest/user/1" method = "post" > < input type = "hidden" name = "_method" value = "PUT" > < input type = "submit" value = "put" > </ form > < form action = "rest/user/1" method = "post" > < input type = "submit" value = "post" > </ form > < form action = "rest/user/1" method = "get" > < input type = "submit" value = "get" > </ form > < form action = "rest/user/1" method = "post" > < input type = "hidden" name = "_method" value = "DELETE" > < input type = "submit" value = "delete" > </ form > |
十三、返回json格式的字符串
1.导入以下jar包
2.方法代码
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@Controller @RequestMapping ( "/json" ) public class jsonController { @ResponseBody @RequestMapping ( "/user" ) public User get(){ User u = new User(); u.setId( 1 ); u.setName( "jayjay" ); u.setBirth( new Date()); return u; } } |
十四、异常的处理
1.处理局部异常(Controller内)
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@ExceptionHandler public ModelAndView exceptionHandler(Exception ex){ ModelAndView mv = new ModelAndView( "error" ); mv.addObject( "exception" , ex); System.out.println( "in testExceptionHandler" ); return mv; } @RequestMapping ( "/error" ) public String error(){ int i = 5 / 0 ; return "hello" ; } |
2.处理全局异常(所有Controller)
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@ControllerAdvice public class testControllerAdvice { @ExceptionHandler public ModelAndView exceptionHandler(Exception ex){ ModelAndView mv = new ModelAndView( "error" ); mv.addObject( "exception" , ex); System.out.println( "in testControllerAdvice" ); return mv; } } |
3.另一种处理全局异常的方法
在SpringMVC配置文件中配置
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<!-- configure SimpleMappingExceptionResolver --> < bean class = "org.springframework.web.servlet.handler.SimpleMappingExceptionResolver" > < property name = "exceptionMappings" > < props > < prop key = "java.lang.ArithmeticException" >error</ prop > </ props > </ property > </ bean > |
error是出错页面
十五、设置一个自定义拦截器
1.创建一个MyInterceptor类,并实现HandlerInterceptor接口
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public class MyInterceptor implements HandlerInterceptor { @Override public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3) throws Exception { System.out.println( "afterCompletion" ); } @Override public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3) throws Exception { System.out.println( "postHandle" ); } @Override public boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2) throws Exception { System.out.println( "preHandle" ); return true ; } } |
2.在SpringMVC的配置文件中配置
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<!-- interceptor setting --> < mvc:interceptors > < mvc:interceptor > < mvc:mapping path = "/mvc/**" /> < bean class = "test.SpringMVC.Interceptor.MyInterceptor" ></ bean > </ mvc:interceptor > </ mvc:interceptors > |
3.拦截器执行顺序
十六、表单的验证(使用Hibernate-validate)及国际化
1.导入Hibernate-validate需要的jar包
(未选中不用导入)
2.编写实体类User并加上验证注解
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public class User { public int getId() { return id; } public void setId( int id) { this .id = id; } public String getName() { return name; } public void setName(String name) { this .name = name; } public Date getBirth() { return birth; } public void setBirth(Date birth) { this .birth = birth; } @Override public String toString() { return "User [id=" + id + ", name=" + name + ", birth=" + birth + "]" ; } private int id; @NotEmpty private String name; @Past @DateTimeFormat (pattern= "yyyy-MM-dd" ) private Date birth; } |
ps:@Past表示时间必须是一个过去值
3.在jsp中使用SpringMVC的form表单
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< form:form action = "form/add" method = "post" modelAttribute = "user" > id:< form:input path = "id" />< form:errors path = "id" />< br > name:< form:input path = "name" />< form:errors path = "name" />< br > birth:< form:input path = "birth" />< form:errors path = "birth" /> < input type = "submit" value = "submit" > </ form:form > |
ps:path对应name
4.Controller中代码
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@Controller @RequestMapping ( "/form" ) public class formController { @RequestMapping (value= "/add" ,method=RequestMethod.POST) public String add( @Valid User u,BindingResult br){ if (br.getErrorCount()> 0 ){ return "addUser" ; } return "showUser" ; } @RequestMapping (value= "/add" ,method=RequestMethod.GET) public String add(Map<String,Object> map){ map.put( "user" , new User()); return "addUser" ; } } |
ps:
1.因为jsp中使用了modelAttribute属性,所以必须在request域中有一个"user".
2.@Valid 表示按照在实体上标记的注解验证参数
3.返回到原页面错误信息回回显,表单也会回显
5.错误信息自定义
在src目录下添加locale.properties
NotEmpty.user.name=name can't not be empty Past.user.birth=birth should be a past value DateTimeFormat.user.birth=the format of input is wrong typeMismatch.user.birth=the format of input is wrong typeMismatch.user.id=the format of input is wrong
在SpringMVC配置文件中配置
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<!-- configure the locale resource --> < bean id = "messageSource" class = "org.springframework.context.support.ResourceBundleMessageSource" > < property name = "basename" value = "locale" ></ property > </ bean > |
6.国际化显示
在src下添加locale_zh_CN.properties
username=账号 password=密码
locale.properties中添加
username=user name password=password
创建一个locale.jsp
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< body > < fmt:message key = "username" ></ fmt:message > < fmt:message key = "password" ></ fmt:message > </ body > |
在SpringMVC中配置
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<!-- make the jsp page can be visited --> < mvc:view-controller path = "/locale" view-name = "locale" /> |
让locale.jsp在WEB-INF下也能直接访问
最后,访问locale.jsp,切换浏览器语言,能看到账号和密码的语言也切换了
十七、压轴大戏--整合SpringIOC和SpringMVC
1.创建一个test.SpringMVC.integrate的包用来演示整合,并创建各类
2.User实体类
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public class User { public int getId() { return id; } public void setId( int id) { this .id = id; } public String getName() { return name; } public void setName(String name) { this .name = name; } public Date getBirth() { return birth; } public void setBirth(Date birth) { this .birth = birth; } @Override public String toString() { return "User [id=" + id + ", name=" + name + ", birth=" + birth + "]" ; } private int id; @NotEmpty private String name; @Past @DateTimeFormat (pattern= "yyyy-MM-dd" ) private Date birth; } |
3.UserService类
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@Component public class UserService { public UserService(){ System.out.println( "UserService Constructor...\n\n\n\n\n\n" ); } public void save(){ System.out.println( "save" ); } } |
4.UserController
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@Controller @RequestMapping ( "/integrate" ) public class UserController { @Autowired private UserService userService; @RequestMapping ( "/user" ) public String saveUser( @RequestBody @ModelAttribute User u){ System.out.println(u); userService.save(); return "hello" ; } } |
5.Spring配置文件
在src目录下创建SpringIOC的配置文件applicationContext.xml
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<? xml version = "1.0" encoding = "UTF-8" ?> xsi:schemaLocation="http://www.springframework.org/schema/beans " > < context:component-scan base-package = "test.SpringMVC.integrate" > < context:exclude-filter type = "annotation" expression = "org.springframework.stereotype.Controller" /> < context:exclude-filter type = "annotation" expression = "org.springframework.web.bind.annotation.ControllerAdvice" /> </ context:component-scan > </ beans > |
在Web.xml中添加配置
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<!-- configure the springIOC --> < listener > < listener-class >org.springframework.web.context.ContextLoaderListener</ listener-class > </ listener > < context-param > < param-name >contextConfigLocation</ param-name > < param-value >classpath:applicationContext.xml</ param-value > </ context-param > |
6.在SpringMVC中进行一些配置,防止SpringMVC和SpringIOC对同一个对象的管理重合
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<!-- scan the package and the sub package --> < context:component-scan base-package = "test.SpringMVC.integrate" > < context:include-filter type = "annotation" expression = "org.springframework.stereotype.Controller" /> < context:include-filter type = "annotation" expression = "org.springframework.web.bind.annotation.ControllerAdvice" /> </ context:component-scan > |
十八、SpringMVC详细运行流程图
十九、SpringMVC与struts2的区别
1、springmvc基于方法开发的,struts2基于类开发的。springmvc将url和controller里的方法映射。映射成功后springmvc生成一个Handler对象,对象中只包括了一个method。方法执行结束,形参数据销毁。springmvc的controller开发类似web service开发。
2、springmvc可以进行单例开发,并且建议使用单例开发,struts2通过类的成员变量接收参数,无法使用单例,只能使用多例。
3、经过实际测试,struts2速度慢,在于使用struts标签,如果使用struts建议使用jstl。