Spring框架--MVC学习

创建一个maven项目

pom.xml配置文件

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.uek.objuct</groupId>
  <artifactId>spring-app</artifactId>
  <version>0.1</version>
  <packaging>war</packaging>
<properties>
  <project.bulid.sourceEncoding>UTF-8</project.bulid.sourceEncoding>
  <failOnMissingWebXml>false</failOnMissingWebXml>
  <!-- 自定义版本标记  -->
  <spring.version>5.1.7.RELEASE</spring.version>
  </properties>
  <!-- 配置项目所需要的第三方的jar包 -->
   <dependencies>
       <!--Servlet api  -->
    <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
    </dependency>
      <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>  
    </dependency> 

<!-- https://mvnrepository.com/artifact/junit/junit  Junit单元测试-->
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>${spring.version}</version>
    <scope>test</scope>
</dependency>
<!--Spring  框架 IOC 第一天要引入的  --> 
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>${spring.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>${spring.version}</version>
</dependency>
<!-- Spring5 AOP -->
<dependency>
   <groupId>org.aspectj</groupId>
    <artifactId>aspectjrt</artifactId>
    <version>1.8.10</version>    
</dependency>
<dependency>
   <groupId>aopalliance</groupId>
    <artifactId>aopalliance</artifactId>
    <version>1.0</version>    
</dependency>
<dependency>
   <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.8.10</version>        
</dependency>
<dependency>
   <groupId>org.springframework</groupId>
    <artifactId>spring-aop</artifactId>
    <version>${spring.version}</version>        
</dependency>

    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java   Mysql数据库驱动  -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.48</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/druid    Druid数据库连接池-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.20</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>${spring.version}</version>
</dependency>
<!-- Spring与Spring MVC 的整合 -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>${spring.version}</version>
</dependency>

<!--阿里的fastJSON处理工具  -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.62</version>
</dependency> 

   </dependencies>
   
   
   <!-- 4.配置构建插件 -->
   <build>
      <plugins>
        <!-- 编译插件 -->
        <plugin>
         <artifactId>maven-compiler-plugin</artifactId>
        <version>3.5.1</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
        </plugin>
        <!-- Tomcat插件 -->
        <plugin>
        <groupId>org.apache.tomcat.maven</groupId>
        <artifactId>tomcat7-maven-plugin</artifactId>
        <version>2.2</version>
        <configuration>
          <port>8080</port>
          <path>/uservlet</path>   
          <!-- 实现热部署   不需要每次修改代码后都重启启动Tomcat -->
        </configuration>
      </plugin>
      
      </plugins>
   
   </build>
   
</project>

基于注解的配置类（JavaConfig的形式配置）

@Configuration
@EnableWebMvc
@ComponentScan({"mvc"})
public class AppConfig {
	/*
	 * jsp的解析器
	 *  这个Bean的作用就是告诉Spring MVC你写的jsp文件的位置
	 * @return
	 */
	@Bean
	public UrlBasedViewResolver  setupViewResolver(){
		UrlBasedViewResolver resolver  = new UrlBasedViewResolver();
		resolver.setPrefix("/WEB-INF/");    //位置（受保护的，不可以直接访问）
		resolver.setSuffix(".jsp");    //jsp文件的后缀，你在写页面的时候就省略掉后缀
		resolver.setViewClass(JstlView.class);
		return resolver;
		
	}
}

Tomcat启动的时候会检测是否有WebApplicationInitializer接口的类，
若检测到有这个类，就会实例化它，并调用它的onStartup方法

public class WebInitializer implements WebApplicationInitializer  {

	@Override
	public void onStartup(ServletContext servletContext) throws ServletException {
		
		System.out.println("starup invoker the method...");
		
		//1.构造Spring容器
		AnnotationConfigWebApplicationContext ctx  = new AnnotationConfigWebApplicationContext();
		
		//2.Spring容器加载配置
		ctx.register(AppConfig.class);
		
		//3.Spring容器接管ServletContext应用上下文对象
		ctx.setServletContext(servletContext);
		
		//4.添加Servlet（至少添加一个Servlet，SpringMVC框架实现的入口Servlet）
		ServletRegistration.Dynamic servlet = servletContext.addServlet("dispatcher",new DispatcherServlet(ctx));
		servlet.addMapping("/");
		servlet.setLoadOnStartup(1);
		
	}

实体类

public class User {
	private String name;
	private int age;
	public User(){}
	public User(String name, int age) {
		super();
		this.name = name;
		this.age = age;
	}
	@Override
	public String toString() {
		return "User [name=" + name + ", age=" + age + "]";
	}
	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;
	}
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + age;
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		User other = (User) obj;
		if (age != other.age)
			return false;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		return true;
	}
	
	
}

练习

@Controller
@RequestMapping("user")
public class HelloController {
	
	@RequestMapping("/hello")
	public void hello(){
		System.out.println("hello 大帅哥");
	}
	
	@RequestMapping("/hi")
	public void hi(){
		System.out.println("hi 对面的女孩看过来");
	}
	
	@RequestMapping("/index")    //映射路径
	public String index(HttpServletRequest request,HttpServletResponse response){   //方法名
		System.out.println(request.getParameter("name"));
		System.out.println(request.getParameter("password"));
		
		/*try {
			PrintWriter out = response.getWriter();
			out.write("hello word");
			out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}*/
		return "index";   //页面的名字
	}
	
	@RequestMapping("/login")
	public String login(){
		return "login";
	}
	
	@RequestMapping("/date")
	@ResponseBody
	public  String aaa(){
		//1.先从后台查数据
		List<User> users = new ArrayList<User>();
		users.add(new User("zhangsan",18));
		users.add(new User("lisi",19));
		users.add(new User("wangwu",20));
		
		//2.用alibaba的fastJson工具   拼接字符串
		String jsonStr = JSON.toJSONString(users);
		return jsonStr;
		/*return "[{'name':zhangsan,'age':18}],"
		        +"{'name':lisi,'age':19},"
		        +"{'name':wangwu,'age':20}]";   自己拼接字符串*/
	}
	
	/*
	 * 返回得是页面，并且可以给页面传递数据
	 * @return 
	 */
	@RequestMapping("/test")
	public ModelAndView bbb(HttpServletRequest request,HttpServletResponse response) {
		
		ModelAndView mv = new ModelAndView("test");
		mv.addObject("message", "my love");
		mv.addObject("username",new ArrayList<User>());
		return mv;
		
		//底层：
		/*request.setAttribute("message", "hello");
		try {
			request.getRequestDispatcher("/WEB-INF/test.jsp").forward(request, response);
		} catch (ServletException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		*/
	}
	
	
	@RequestMapping("/users1")
	@ResponseBody
	public String getUser1(int pageNo,int pageSize){
		System.out.println(pageNo);
		System.out.println(pageSize);
		return "[]";
	}
	
	@RequestMapping("/users2")
	@ResponseBody
	public String getUser2(HttpServletRequest request,HttpServletResponse response){
		request.getParameter("pagaNo");
		request.getParameter("pageSize");
		return "[]";
	}
	//RestFul形式的接口：
	@RequestMapping("/users3/{pageNo}/{pageSize}")    
	@ResponseBody
	public String getUser3(@PathVariable("pageNo") int pageNo,@PathVariable("pageSize") int pageSize){
		System.out.println(pageNo);
		System.out.println(pageSize);
		return "[]";
	}
	
	/*
	@RequestMapping(value="/c",method=RequestMethod.POST)   
	@ResponseBody
	public String c(){
		System.out.println("aaaa");
		return "";
	}*/
	
	//get请求
	@GetMapping("/get")
	public void test(){
		System.out.println("get request");
	}
	//POST
	@PostMapping("/post")
	public void test1(){
		System.out.println("post request");
	}
}

在webapp下新建文件夹WEB-INF

index.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<p>Hello nihao</p>
<form action="c" method="post">
	<input type="submit" value="submit">
</form>
</body>
</html>

login.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<h2>我想要你带你去烂漫的土耳其，然后一起去东京和巴黎</h2>
</body>
</html>

test.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
${ message } 
</body>
</html>	

jdbc.properties
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db_chat
jdbc.username=root
jdbc.password=