第二天，看到第三章SpringMVC的常用注解了，接下来一起学SpringMVC的常用注解吧
首先，创建一个新的项目

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选maven，然后next
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第一栏填包名，第二栏写项目名，具体的命名规则参考
Java包（package）的命名规范，java中package命名规则
然后next
然后点finish
然后配置web，点左上角File--->Project Structure...
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配置
创建web模块
然后点OK
现在文件目录如下所示：
文件目录
maven导包：修改pom.xml，内容如下

   <!--这个参数用于统一配备Spring的版本-->
    <properties>
        <spring.version>4.2.0.RELEASE</spring.version>
    </properties>
    <!--需要用到的编译插件-->
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <!--依赖-->
    <dependencies>
        <!-- https://mvnrepository.com/artifact/aopalliance/aopalliance -->
        <dependency>
            <groupId>aopalliance</groupId>
            <artifactId>aopalliance</artifactId>
            <version>1.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-aop -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context-support -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-expression -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-instrument -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-instrument</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-instrument-tomcat -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-instrument-tomcat</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jms -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jms</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-messaging -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-messaging</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-oxm -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-oxm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-test -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-websocket -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-websocket</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>


    </dependencies>

在web.xml中添加servlet，添加内容如下：

    <servlet>
        <!--Servlet的名称-->
        <servlet-name>dispatcher</servlet-name>
        <!--Servlet对应的java类-->
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <!--web应用启动时立即加载Servlet-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <!--Servlet的映射声明-->
    <servlet-mapping>
        <!--对应Servlet的名称-->
        <servlet-name>dispatcher</servlet-name>
        <!--标识监听当前的所有请求-->
        <url-pattern>/</url-pattern>
    </servlet-mapping>

接着HelloController.java文件

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@Controller
public class HelloController {
    @RequestMapping("/hello")
    public String hello(Model model){
        return "hello";
    }
}

最后在WEB-INF的中添加dispatcher-servlet配置文件：

添加dispatcher拦截器的配置文件，命名格式为servlet_name-servlet.xml

dispatcher-servlet.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"
       xmlns:context="http://www.springframework.org/schema/context"
       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.xsd">

    <!--Spring可以自动扫描base-package下面的子包或者子包下面的java文件，将于Spring注解相关的类注册为Spring的Bean-->
    <context:component-scan base-package="pers.congcong.controller"/>
    <!--视图解析器-->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--前缀-->
        <property name="prefix">
            <value>/WEB-INF/jsp</value>
        </property>
        <!--后缀-->
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>


</beans>

然后创建一个jsp文件

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我把昨天写的直接粘贴过来了

<%@ 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>Hello World啦啦啦哎哎哎</title>
</head>
<body>
哎哎哎哎哎
</body>
</html>

最后配置服务器

配置服务器

然后点Apply
然后运行

运行

翻车了

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jsp后面少了一个/，给他加上
修改dispatcher-servlet.xml

<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--前缀-->
        <property name="prefix">
            <value>/WEB-INF/jsp/</value>
        </property>
        <!--后缀-->
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>

改回来，接着运行。

可以了

然后是一段话，SpringMVC中用于参数绑定的注解有很多，都在org.springframework.web.bind.annotation包中，根据它们处理request的不同可以分为四类（主要讲解常用类型）：
处理request body部分的注解：
@RequestParam
@RequestBody
处理requet uri部分的注解
@PathVariable
处理request header部分的注解
@RequestHeader
@CookieValue
处理attribute类型的注解
@SessionAttribute
@ModelAttribute

一脸懵逼，这些注解就一个单词解决，就不能走点心吗！

接下来讲RequestMapping的属性：

value属性
用来映射一个请求或一种方法

   @RequestMapping(value = "/parame" )
    public ModelAndView hello(){
        return ...;
    }
或者
@RequestMapping("parame")
    public String hello(){
        return "hello";
    }

mothod属性：
用来指示该方法仅仅处理哪些HTTP请求
RequestMethod.POST
...GET
...HEAD
...OPTIONS
...PUT
...PATCH
...DELETE
...TRACE
等方法

consume属性，指定处理请求的提交内容类型
    @RequestMapping(value = "/parame", method = RequestMethod.POST, consumes = "application/json")
表示该方法仅用于处理request Content-Type为“application/json”类型的请求

produces属性
该属性指定返回的内容类型，返回的内容类型必须是request请求头（Accept）中所包含的类型
   @RequestMapping(value = "/parame", method = RequestMethod.POST, produces = "application/json")
    public String hello(){
        return "hello";
    }
表示该方法仅用于处理request Access头中包含“application/json”的请求，同时指明返回的内容类型为“application/json”

params属性
 @RequestMapping(value = "/parame", params = "myParam = myValue")
    public String hello(){
        return "hello";
    }
仅处理符合要求的请求

header属性
    @RequestMapping(value = "/parame",method = RequestMethod.POST, headers = "Referer = http://www.congcong.com")
表示仅处理header中包含指定的“Referer”请求头和对应的值“http://www.congcong.com”的请求

请求处理方法可出现的参数类型：

• Javax.servlet.ServletRequest或Javax.servlet.http.HttpServletRequest
• Javax.servlet.ServletResponse或Javax.servlet.http.HttpServletResponse
• javax.servlet.http.HttpSession
• org.springframework.web.context.request.WebRequest
  或org.springframework.web.context.request.NativeWebRequest
• java.util.Locale
• java.io.InputStream 或java.io.Reader
• java.io.OutputStream或 java.io.Writer
• java.security.Principal
• HttpEntity<?>
• java.util.Map
• org.springframework.ui.Model
• org.springframework.ui.ModelMap
• org.springframework.ui.Model
• org.springframework.web.servlet.mvc.support.RedierctAttributes
• org.springframework.validation.Errors
• org.springframework.validation.BindingResult
• org.springframework.web.bind.support.SessionStatus
• org.springframework.web.util.UriComponentsBuilder
• @PathVariable、@MarixVariable
• @ReqeustParam @RequestHeader @ReqesetBody @RequestPart注解

请求可返回的参数类型

• org.springframework.web.portlet.ModelAndView
• org.springframework.ui.Model
• java.util.Map<k,v>
• org.springframework.web.servlet.View
• java.lang.String
• HttpEntity或ResponseEntity
• java.util.concurrent.Callable
• org.springframework.web.context.request.async.DeferredResult
• void