1. 环境配置

1.1 导入jar包

commons-logging-1.2.jar
jstl.jar
spring-aop-5.0.8.RELEASE.jar
spring-aspects-5.0.8.RELEASE.jar
spring-beans-5.0.8.RELEASE.jar
spring-context-5.0.8.RELEASE.jar
spring-core-5.0.8.RELEASE.jar
spring-expression-5.0.8.RELEASE.jar
spring-web-5.0.8.RELEASE.jar
spring-webmvc-5.0.8.RELEASE.jar

1.2 xml配置

web.xml基本配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	id="WebApp_ID" version="2.5">
	<display-name>SpringMVC-01-HelloWorld</display-name>
	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
		<welcome-file>index.htm</welcome-file>
		<welcome-file>index.jsp</welcome-file>
		<welcome-file>default.html</welcome-file>
		<welcome-file>default.htm</welcome-file>
		<welcome-file>default.jsp</welcome-file>
	</welcome-file-list>
	<!-- 中央控制器 (类比struts2的全局拦截器) -->
	<servlet>
		<servlet-name>springmvc</servlet-name>
		<!-- DispatcherServlet主要用于控制流程 -->
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath:springmvc.xml</param-value>
		</init-param>
		<!-- 当值为0或者大于0时，表示容器在启动时就加载并初始化这个servlet -->
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>springmvc</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

DispatcherServlet是前置控制器，配置在web.xml文件中的。拦截匹配的请求，Servlet拦截匹配规则要自己定义，把拦截下来的请求，依据相应的规则分发到目标Controller来处理

根据上面的<servlet-name>springmvc</servlet-name>配置我们还要在src下新建一个springmvc.xml配置如下：

<?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:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/aop 
           http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
           http://www.springframework.org/schema/tx 
           http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
        <!--指定扫描controller -->
	<context:component-scan base-package="cn.itcast_01_springmvc.controller"></context:component-scan>
	<!-- 视图解析器 -->
	<bean
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/jsp/"></property>
		<property name="suffix" value=".jsp"></property>
	</bean>
</beans>

其中"视图解析器"指明了要映射的jsp路径的结构目录，所以在WEB-INF下新建jsp文件夹放置jsp文件，在下面随便建一个jsp文件，命名为hello.jsp

新建cn.itcast_01_springmvc.controller以及Hello.java实例：

//通知spring需要扫描这个类，得到DispatchService解析
//注解相当于调用这个类,里面的参数相当于对应的构造方法
//访问路径名:http://localhost:8080/SpringMVC-01-HelloWorld/hello/world
//@Controller相当于<bean>注入，参考下面的struts2的<action>注入原理
@Controller
@RequestMapping("/hello")
public class Hello {
	//类似配置action,默认为method=RequestMethod.GET请求 
	@RequestMapping(value="/world")//,method=RequestMethod.POST
	public String hello() {
		System.out.println("hello");
		//返回要调用的jsp页面
		return "hello";
	}
}
//<package name="struct2" namespace="/" extends="struts-default">
//	<action name="hello" class="cn.itcast._01_hello.HelloAction" method="hello">
//		<result  type="dispatcher" name="good">hello.jsp</result>
//	</action>
//</package>

运行将会看到你的jsp页面

2. 页面跳转

2.1 实现代码

在Hello.java下添加如下的代码：

@RequestMapping(value="/loginForm")
public String loginFrom() {
	return "login";
}

在jsp下新建login页面：

<%@ 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>
<form action="login" method="post">
账号：<input name="user" />
密码：<input name="pass" />
<button>登陆</button>
</form>
</body>
</html>

根据login页面我们登陆后要跳转到成功页面，所以提交到后台代码还要执行跳转页面：

@RequestMapping(value="/login",method=RequestMethod.POST)
public String login(String user,String pass) {
	System.out.println("login"+user);
	return "redirect:world";
}

登陆提交后重定向到刚才的Hello.jsp则跳转成功

2.2 post编码同一

在后台打印的中文发生乱码，解决方法如下：
在web.xml中新增节点：

<!-- 统一编码 -->
<filter>
	<filter-name>setcharacter</filter-name>
	<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
	<init-param>
		<param-name>encoding</param-name>
		<param-value>UTF-8</param-value>
	</init-param>
</filter>
<filter-mapping>
	<filter-name>setcharacter</filter-name>
	<url-pattern>/*</url-pattern>
</filter-mapping>

2.3 页面错误分析

500错误：一般由于后台的java代码错误

404错误：xml文件的配置错误

405错误：同一工作前台和后台post请求与get请求交替使用错误

3. 参数传递

新建UserController.java添加如下代码：

@Controller
public class UserController {
	@RequestMapping(value = "/list")
	public String list( Integer currentpage,Integer pagesize) {
		System.out.println("currentpage:" + currentpage);
		System.out.println("pagesize:" + pagesize);
		return "hello";
	}
}

你可以用如下方法测试并打印结果：

http://localhost:8080/SpringMVC-01-HelloWorld/list?currentpage=2&pagesize=100

当然要注意，如果不传值则会报null，用整形会报错，所以要用包装类Integer，还可以给参数设置默认值，方法改为：

@RequestMapping(value = "/list")
public String list(@RequestParam(value = "currentpage", defaultValue = "1") Integer currentpage,
		@RequestParam(value = "pagesize", defaultValue = "10") Integer pagesize) {
	System.out.println("currentpage:" + currentpage);
	System.out.println("pagesize:" + pagesize);
	return "hello";
}

你还可以用 @PathVariable(value="id")将连接字符拼接到url上

@RequestMapping("/get/{id}")
public String get(@PathVariable(value="id") Integer id){
	System.out.println("id:"+id);
	return "hello";
}

http://localhost:8080/SpringMVC-01-HelloWorld/get/1

4. 使用Maven构建项目

4.1 基本构建

需要安装Maven插件，eclipse自带可能版本过低，具体操作请见百度

新建项目二为SpringMVC-02-Mvn，利用pom.xml配置jar包：

<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>cn.itcast</groupId>
	<artifactId>SpringMVC-02-Mvn</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>
	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<spring.version>5.0.8.RELEASE</spring.version>
	</properties>
	<dependencies>
		<!-- <dependency> -->
		<!-- <groupId>javax.servlet</groupId> -->
		<!-- <artifactId>servlet-api</artifactId> -->
		<!-- <version>2.5</version> -->
		<!-- <scope>provided</scope> -->
		<!-- </dependency> -->
		<!-- spring核心包 -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</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>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-expression</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-websocket</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-tx</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-jdbc</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<!-- AOP aspect -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-aop</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-aspects</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>commons-logging</groupId>
			<artifactId>commons-logging</artifactId>
			<version>1.2</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context-support</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-test</artifactId>
			<version>${spring.version}</version>
		</dependency>

		<!-- JSTL标签类 -->
		<dependency>
			<groupId>jstl</groupId>
			<artifactId>jstl</artifactId>
			<version>1.2</version>
		</dependency>
		<!-- json -->
		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
			<version>2.9.5</version>
		</dependency>
		<!-- jsonp -->
		<dependency>
			<groupId>com.google.code.gson</groupId>
			<artifactId>gson</artifactId>
			<version>2.8.5</version>
		</dependency>
		<!-- 下载 -->
		<dependency>
			<groupId>commons-fileupload</groupId>
			<artifactId>commons-fileupload</artifactId>
			<version>1.3.3</version>
		</dependency>

	</dependencies>
</project>

web.xml的DispatcherServlet配置与post编码照搬过来

springmvc.xml放在src/main/resources，代码照搬

在WEB-INF建立jsp文件夹和home.jsp，内容随意

新建cn.itcast_01_springmvc.controller和类IndexController.java

4.2 一些注解的使用

IndexController后台代码：

//获取cookie的内置参数值
@RequestMapping("/testCookie")
public String testCookie(@CookieValue("JSESSIONID") String sessionID) {
    System.out.println(sessionID);
    return "home";
}
// 获取一类请求头参数
@RequestMapping("/testHeader")
public String testHeader(@RequestHeader(value = "User-Agent") String header) {
	System.out.println(header);
	return "home";
}

// 跳转条件设置，pass等于10，跳转失败
@RequestMapping(value = "/testparam", params = { "user", "pass!=10" })
public String testParam(String user, Integer pass) {
	System.out.println(user + " " + pass);
	return "home";
}

//test前接受任意字符访问
@RequestMapping(value = "/*test")
public String test() {
	return "home";
}

5. 数据回传

5.1 构建数据提交

新建cn.itcast_01_springmvc.pojo和实体类：

public class Address {
	private Integer id;
	private String province;
	private String city;
//...

public class User {
	private Integer id;
	private String usern;
	private String pass;
	private String email;
	private Integer age;
	private Address address;
//...

在jsp下新建文件夹user和form.jsp(关于${sessionScope.str1}见5.3)：

<%@ 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>
${sessionScope.str1}<br />
${sessionScope.str2}
<form action="save1">
账号：<input name="usern" value="${user.usern}"><br />
密码：<input name="pass" value="${user.pass}"/><br />
年龄：<input name="age" value="${user.age}"/><br />
邮箱：<input name="email" value="${user.email}"/><br />
省份：<input name="address.province" value="${user.address.province}"/><br />
城市：<input name="address.city" value="${user.address.city}"/><br />
<button>注册</button>
</form>
</body>
</html>

控制层代码：

//Controller 负责处理由DispatcherServlet 分发的请求，它把用户请求的
//数据经过业务处理层处理之后封装成一个Model ，然后再把该Model 返回给对应的View 
//进行展示。在SpringMVC 中提供了一个非常简便的定义Controller 的方法，然后
//使用@RequestMapping 和@RequestParam 等一些注解用以定义URL请求和Controller 方法之间的映射，这样的Controller 就能被外界访问到。
@Controller
public class UserController {
	@Autowired
	private UserDao userDao;

@RequestMapping(value = "/form")
public String test() {
	return "user/form";
}

@RequestMapping(value = "/save1")
 public String save1(User user) {
    System.out.println(user.toString());
	return "home";
}

5.2 数据回传方式

后台代码增加：

 // 将数据传到前台ModelAndView
	 @RequestMapping(value = "/edit1")
	 public ModelAndView edit1() {
	 User user = new User();
	 user.setUser("Bob");
	 user.setPass("123");
	 user.setAge(12);
	 user.setEmail("[email protected]");
	 Address address = new Address();
	 address.setCity("成都");
	 address.setProvince("四川");
	 user.setAddress(address);
	 ModelAndView mv = new ModelAndView();
	 mv.setViewName("user/form");
	 mv.addObject("user", user);
	 return mv;
}	
	 // 将数据传到前台Map
	 @RequestMapping(value = "/edit2")
	 public String edit2(Map<String, Object> map) {
	 User user = new User();
	 user.setUser("Lisa");
	 user.setPass("123");
	 user.setAge(12);
	 user.setEmail("[email protected]");
	 Address address = new Address();
	 address.setCity("成都");
	 address.setProvince("四川");
	 user.setAddress(address);
	 map.put("user", user);
	 return "user/form";
}	
	 // 将数据传到前台Model
         //这里将user的信息存入session，只字符存入session，当然这个注解可以放在类上面
         @SessionAttributes(value = { "user" }, types = { String.class })
	 @RequestMapping(value = "/edit3")
	 public String edit3(Model model) {
	 User user = new User();
	 user.setUser("Lucy");
	 user.setPass("123");
	 user.setAge(12);
	 user.setEmail("[email protected]");
	 Address address = new Address();
	 address.setCity("成都");
	 address.setProvince("四川");
	 user.setAddress(address);
	 model.addAttribute("user", user);
	
	 model.addAttribute("str1", "session1");
	 model.addAttribute("str2", "session2");
	 return "user/form";
}

上面实现了三种方式的数据回传到form.jsp，一般使用Model

5.3 session注解的使用

上面的后台代码中，最后使用了注解和model.addAttribute("str1", "session1");将值存入session，前面的前台代码利用EL表达式取出相应的值

6. 原生API

需要把tomcat的环境包build进来

HttpServletRequest
HttpServletResponse
HttpSession
java.security.Principal
Locale
InputStream
OutputStream
Reader
Writer

这里不做详讲，写个HttpSession测试类：

@Controller
public class HttpController {
	//内置api的session
	@RequestMapping("/http")
	public String http(HttpSession session) {
		System.out.println(session.getId());
		return "home";
	}
}

SpringMVC基础总结