SpringMVC学习笔记

发布：2021/7/25 22:46:40作者：管理员来源：本站浏览次数：1203

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

  <!--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

<?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-4.1.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

@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

    //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

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

    //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

    //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

    //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

    //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

          $(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

    //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

    <!-- upload settings --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="maxUploadSize" value="102400000"></property> </bean>

3.方法代码

    @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

      <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

@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

@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

  <!-- 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

    <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

@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）

 @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）

@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

    <!-- 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

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

    <!-- 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

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

    <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

@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

    <!-- 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

  <body> <fmt:message key="username"></fmt:message> <fmt:message key="password"></fmt:message> </body>

在SpringMVC中配置

    <!-- 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

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

@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

@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

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" 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.xsd 
        http://www.springframework.org/schema/util 
        http://www.springframework.org/schema/util/spring-util-4.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        " xmlns:util="http://www.springframework.org/schema/util" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" > <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

  <!-- 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

<!-- 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运行原理

1. 客户端请求提交到DispatcherServlet
2. 由DispatcherServlet控制器查询一个或多个HandlerMapping，找到处理请求的Controller
3. DispatcherServlet将请求提交到Controller
4. Controller调用业务逻辑处理后，返回ModelAndView
5. DispatcherServlet查询一个或多个ViewResoler视图解析器，找到ModelAndView指定的视图
6. 视图负责将结果显示到客户端

二十、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。

　JdbcTemplate实现CRUD操作

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