SpringMVC學習筆記

時間 2020-06-03

原文原文鏈接

轉:http://www.cnblogs.com/sunniest/p/4555801.html#!commentshtml

1、SpringMVC基礎入門，建立一個HelloWorld程序

1.首先，導入SpringMVC須要的jar包.java

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.spring.mvc</groupId>
    <artifactId>spring-mvc-action-tutorial</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>

    <name>notes Maven Webapp</name>
    <url>http://maven.apache.org</url>

    <properties>
        <!-- Spring版本號 -->
        <spring.version>4.1.6.RELEASE</spring.version>
    </properties>

    <dependencies>
        <!-- SpringMVC所需jar包 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <!-- 一個簡單的適配器, 爲'全部的java日誌實現'提供一個統一的接口 -->
        <dependency>
            <groupId>commons-logging</groupId>
            <artifactId>commons-logging</artifactId>
            <version>1.2</version>
        </dependency>

        <!-- 文件上傳 -->
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.4</version>
        </dependency>

        <!-- Servlet Api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>

        <!-- 返回json數據 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.2.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.2.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.2.1</version>
        </dependency>

        <!-- Hibernate-validate須要的jar包 -->
        <dependency>
            <groupId>com.fasterxml</groupId>
            <artifactId>classmate</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.logging</groupId>
            <artifactId>jboss-logging</artifactId>
            <version>3.1.3.GA</version>
        </dependency>
        <dependency>
            <groupId>javax.validation</groupId>
            <artifactId>validation-api</artifactId>
            <version>1.1.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.1.3.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator-annotation-processor</artifactId>
            <version>5.1.3.Final</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>spring-mvc-action-tutorial</finalName>
        <defaultGoal>install</defaultGoal>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

2.添加Web.xml配置文件中關於SpringMVC的配置 git

<!--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 github

<?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">
        <!-- 前綴 -->
        <property name="prefix" value="/WEB-INF/jsp/" />
        <!-- 後綴 -->
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

4.在WEB-INF文件夾下建立名爲jsp的文件夾，用來存放jsp視圖。建立一個hello.jsp，在body中添加「Hello World」。 web

5.創建包及Controller，以下所示 ajax

6.編寫Controller代碼spring

@Controller
@RequestMapping("/mvc")
public class mvcController {

    @RequestMapping("/hello")
    public String hello(){        
        return "hello";
    }
}

7.啓動服務器，鍵入 http://localhost:8080/項目名/mvc/hello express

2、配置解析

1.Dispatcherservletapache

　　DispatcherServlet是前置控制器，配置在web.xml文件中的。攔截匹配的請求，Servlet攔截匹配規則要自已定義，把攔截下來的請求，依據相應的規則分發到目標Controller來處理，是配置spring MVC的第一步。json

2.InternalResourceViewResolver

　　視圖名稱解析器

3.以上出現的註解

@Controller 負責註冊一個bean 到spring 上下文中

@RequestMapping 註解爲控制器指定能夠處理哪些 URL 請求

3、SpringMVC經常使用註解

@Controller

　　負責註冊一個bean 到spring 上下文中
@RequestMapping

　　註解爲控制器指定能夠處理哪些 URL 請求
@RequestBody

　　該註解用於讀取Request請求的body部分數據，使用系統默認配置的HttpMessageConverter進行解析，而後把相應的數據綁定到要返回的對象上 ,再把HttpMessageConverter返回的對象數據綁定到 controller中方法的參數上

@ResponseBody

　　該註解用於將Controller的方法返回的對象，經過適當的HttpMessageConverter轉換爲指定格式後，寫入到Response對象的body數據區

@ModelAttribute 　　　

　　在方法定義上使用 @ModelAttribute 註解：Spring MVC 在調用目標處理方法前，會先逐個調用在方法級上標註了@ModelAttribute 的方法

　　在方法的入參前使用 @ModelAttribute 註解：能夠從隱含對象中獲取隱含的模型數據中獲取對象，再將請求參數 –綁定到對象中，再傳入入參將方法入參對象添加到模型中

@RequestParam　

　　在處理方法入參處使用 @RequestParam 能夠把請求參數傳遞給請求方法

@PathVariable

　　綁定 URL 佔位符到入參
@ExceptionHandler

　　註解到方法上，出現異常時會執行該方法
@ControllerAdvice

　　使一個Contoller成爲全局的異常處理類，類中用@ExceptionHandler方法註解的方法能夠處理全部Controller發生的異常

4、自動匹配參數

//match automatically
    @RequestMapping("/person")
    public String toPerson(String name,double age){
        System.out.println(name+" "+age);
        return "hello";
    }

5、自動裝箱

1.編寫一個Person實體類

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裏編寫方法

//boxing automatically
    @RequestMapping("/person1")
    public String toPerson(Person p){
        System.out.println(p.getName()+" "+p.getAge());
        return "hello";
    }

6、使用InitBinder來處理Date類型的參數

//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));
    }

7、向前臺傳遞參數

//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";
    }

前臺可在Request域中取到"p"

8、使用Ajax調用

//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";
    }

前臺用下面的Jquery代碼調用

$(function(){
              $("#btn").click(function(){
                  $.post("mvc/getPerson",{name:$("#name").val()},function(data){
                      alert(data);
                  });
              });
          });

9、在Controller中使用redirect方式處理請求

@RequestMapping("/redirect")
    public String redirect(){
        return "redirect:hello";
    }

10、文件上傳

1.須要下面兩個jar包

commons-fileupload-1.3.1.jar

commons-io-2.4.jar

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.方法代碼

@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.前臺form表單

<form action="mvc/upload" method="post" enctype="multipart/form-data">
          <input type="file" name="file"><br>
          <input type="submit" value="submit">
      </form>

11、使用@RequestParam註解指定參數的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";
    }    
}

12、RESTFul風格的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表單發送put和delete請求

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>

在前臺能夠用如下代碼產生請求

<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>

十3、返回json格式的字符串

1,導入jackson包

2.方法代碼

@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;
    }
}

十4、異常的處理

1.處理局部異常（Controller內）

@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.處理全局異常（全部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.另外一種處理全局異常的方法

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是出錯頁面

十5、設置一個自定義攔截器

1.建立一個MyInterceptor類，並實現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.攔截器執行順序

十6、表單的驗證（使用Hibernate-validate）及國際化

1.導入Hibernate-validate須要的jar包

2.編寫實體類User並加上驗證註解

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表示時間必須是一個過去值

3.在jsp中使用SpringMVC的form表單

<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對應name

4.Controller中代碼

@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.由於jsp中使用了modelAttribute屬性，因此必須在request域中有一個"user".

　　2.@Valid 表示按照在實體上標記的註解驗證參數

　　3.返回到原頁面錯誤信息回回顯，表單也會回顯

5.錯誤信息自定義

在src目錄下添加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.國際化顯示

在src下添加locale_zh_CN.properties

username=帳號
password=密碼

locale.properties中添加

username=user name
password=password

建立一個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"/>

讓locale.jsp在WEB-INF下也能直接訪問

最後，訪問locale.jsp，切換瀏覽器語言，能看到帳號和密碼的語言也切換了

十7、壓軸大戲--整合SpringIOC和SpringMVC

1.建立一個test.SpringMVC.integrate的包用來演示整合，並建立各種

2.User實體類

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類

@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目錄下建立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中進行一些配置，防止SpringMVC和SpringIOC對同一個對象的管理重合

<!-- 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>

十8、SpringMVC詳細運行流程圖

十9、SpringMVC運行原理

1. 客戶端請求提交到DispatcherServlet
2. 由DispatcherServlet控制器查詢一個或多個HandlerMapping，找處處理請求的Controller
3. DispatcherServlet將請求提交到Controller
4. Controller調用業務邏輯處理後，返回ModelAndView
5. DispatcherServlet查詢一個或多個ViewResoler視圖解析器，找到ModelAndView指定的視圖
6. 視圖負責將結果顯示到客戶端

二10、SpringMVC與struts2的區別

一、springmvc基於方法開發的，struts2基於類開發的。springmvc將url和controller裏的方法映射。映射成功後springmvc生成一個Handler對象，對象中只包括了一個method。方法執行結束，形參數據銷燬。springmvc的controller開發相似web service開發。
二、springmvc能夠進行單例開發，而且建議使用單例開發，struts2經過類的成員變量接收參數，沒法使用單例，只能使用多例。
三、通過實際測試，struts2速度慢，在於使用struts標籤，若是使用struts建議使用jstl。

代碼看這裏：https://github.com/mingchunliu2083/springmvc