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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