SpringMVC笔记1
SpringMVC是一个一种基于Java的实现MVC设计模型的请求驱动类型的轻量级web框架
SpringMVC的入门案例
2.导入相关jar包
<?xml version="1.0" encoding="UTF-8"?> <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_day01_01_start</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>springmvc_day01_01_start Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <spring.version>5.0.2.RELEASE</spring.version> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</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> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.0</version> <scope>provided</scope> </dependency> </dependencies> <build> <finalName>springmvc_day01_01_start</finalName> <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <version>3.2.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </pluginManagement> </build> </project>
3,在web.xml中配置前端控制器
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd" > <web-app> <display-name>Archetype Created Web Application</display-name> <servlet> <servlet-name>dispatcherServlet</servlet-name> <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> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcherServlet</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
4.编写控制器类
package cn.itcast.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; //控制器类 @Controller public class HelloController { //用来接收请求 @RequestMapping(path = "/hello") public String sayHello(){ System.out.println("Hello SpringMVC"); return "success"; } }
5.开启扫描注解
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" 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/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc "> <!--开启注解扫描--> <context:component-scan base-package="cn.itcast"></context:component-scan> <!--视图解析器--> <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/pages/"/> <property name="suffix" value=".jsp"></property> </bean> <!--开启SpringMVC框架的支持--> <mvc:annotation-driven></mvc:annotation-driven> </beans>
6.编写两个JSP
首页
<%-- Created by IntelliJ IDEA. User: Yuan Date: 2019/7/21 Time: 14:48 To change this template use File | Settings | File Templates. --%> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <h3>入门程序</h3> <a href="hello">入门程序</a> </body> </html>
成功页面
<%-- Created by IntelliJ IDEA. User: Yuan Date: 2019/7/21 Time: 15:31 To change this template use File | Settings | File Templates. --%> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <h3>入门成功</h3> </body> </html>
入门案例的流程总结
1.服务器启动,加载配置
2.DispatcherServlet对象创建
3.springmvc.xml会开启注解扫描
4.找到HelloController,把他变成对象,加载进入IOC容器当中,
5.InternalResourceViewResolver视图解析器也会变成对象,谁调用该对象,就会帮他跳转页面
RequestMapping注解的作用:用于建立请求URL和处理请求方法之间的对应关系,注解位置用在方法上或者类上
请求参数绑定入门
1.请求地址携带参数username
<body> <%--请求参数绑定--%> <a href="param/testParam?username=hehe">请求参数绑定</a> </body>
2.方法带有参数username
package cn.itcast.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller @RequestMapping("/param") public class ParamController { //请求参数绑定入门 @RequestMapping("/testParam") public String testParam(String username){ System.out.println("执行了...."); System.out.println(username); return "success"; } }
3.自动给方法的参数赋值
//输出结果 //执行了.... //hehe
配置解决中文乱码的过滤器
<filter> <filter-name>characterEncodingFilter</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>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
引用类型的封装
public class User implements Serializable { private String uname; private String age; }
集合类型封装
编写自定义类型转换器
//两个泛型,S表示字符串,T表示想要转换的类型 public interface Converter<S, T>
1.实现接口Converter
package cn.itcast.utils; import org.springframework.core.convert.converter.Converter; import java.text.DateFormat; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; //字符串转日期 public class StringToDateConverter implements Converter<String, Date> { @Override //实现接口方法 public Date convert(String source) { if(source == null){ throw new RuntimeException("没有日期"); } DateFormat df = new SimpleDateFormat("yyyy-MM-dd"); try { return df.parse(source); } catch (Exception e) { throw new RuntimeException("日期转换异常"); } } }
2.配置自定义类型转换器
<!--配置自定义类型转换器--> <bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean"> <property name="converters"> <set> <bean class="cn.itcast.utils.StringToDateConverter"></bean> </set> </property> </bean>
3.开启SpringMVC框架的支持
<!--开启SpringMVC框架的支持--> <mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven>
常用注解
RequestParam注解:
作用:把请求中指定名称的参数给控制器中的形参赋值
属性:
value,请求参数中的名称,
required:请求参数中是否必须提供此参数,默认值:true
RequestBody注解
作用:用于获取请求体内容,直接使用得到是key=value&key=value...结构的数据get请求不适用(get请求没有请求体,把参数都封装到地址栏上)
属性:
required:是否必须有请求体,默认值true,当取值为true时,get请求会报错,如果取值为false,get请求得到是null
PathVariable注解
作用:用于绑定url中的占位符,例如:请求url中/delete{id},这个{id}就是url占位符。url支持占位符是spring3.0之后加入的。是springmvc支持rest风格URL的一个重要标志。
属性:
value:用于指定url中占位符名称
required:是否必须提供占位符
@RequestMapping("/testPathVariable/{sid}") public String testPathVariable(@PathVariable(name="sid") String id){ System.out.println("执行了"); System.out.println(id); return "success"; }
<a href="anno/testPathVariable/10">testPathvariable</a>
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