Spring(二)之入门示例
任何编程技术,特别是入门示例,通常都是Hello World,在这里我也遵循这个业界公认的原则。 这里我使用的maven项目,大家如果想要演示,建议使用Eclipse(含maven插件)或Idea(含maven插件)或Eclipse+本地安装maven3以上等。 ? 一、导入Maven依赖 这里我将基本所需的依赖都导入进去了。 <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.spring</groupId> <artifactId>spring-example01</artifactId> <version>0.0.1-SNAPSHOT</version> <dependencies> <!-- spring核心包 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>4.3.13.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.3.13.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>4.3.13.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>4.3.13.RELEASE</version> </dependency> <dependency> <groupId>aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.5.4</version> </dependency> <dependency> <groupId>aspectj</groupId> <artifactId>aspectjrt</artifactId> <version>1.5.4</version> </dependency> <dependency> <groupId>org.codehaus.jackson</groupId> <artifactId>jackson-mapper-asl</artifactId> <version>1.9.11</version> </dependency> <!--mybatis核心包 --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.1.1</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.1.1</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.21</version> </dependency> <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>0.9.1.2</version> <type>jar</type> </dependency> <!--打印日志 --> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.5</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>4.3.13.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/jsp-api --> <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.1</version> </dependency> <!-- javax.servlet-api --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> </dependency> <!-- spring-web --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>4.3.13.RELEASE</version> </dependency> <!-- spring-webmvc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.3.13.RELEASE</version> </dependency> <!-- 阿里巴巴fastjson --> <dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.41</version> </dependency> <!--dbcp --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-dbcp2</artifactId> <version>2.1.1</version> </dependency> </dependencies> </project> ? 二、编写HelloWord.java package com.tutorialspoint; public class HelloWorld { private String message; void setMessage(String message){ this.message = message; } getMessage(){ System.out.println("Your Message : " + message); } } ? 三、编写MainApp.java import org.springframework.context.ApplicationContext; org.springframework.context.support.ClassPathXmlApplicationContext; MainApp { static main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml"); HelloWorld obj = (HelloWorld) context.getBean("helloWorld"); obj.getMessage(); } } ?
四、创建Beans.xml,将其放入src/main/resources目录下 <?xml version = "1.0" encoding = "UTF-8"?> <beans xmlns = "http://www.springframework.org/schema/beans" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation = "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd"> bean id = "helloWorld" class = "com.tutorialspoint.HelloWorld"> property name = "message" value = "Hello World!"/> </bean> beans> 关于bean id这里要说下,与id对应还有一个name 所以这里要说下bean id 和bean name的区别 共同点:都可通过getBean获取 不同点:(1)bean id是唯一的,而bean name可以非唯一,允许重复,当然了,如果存在两个bean name相同,后者则会覆盖前者; (2)bean id中命名不能以特殊字符,例如×#@,不能以数字开头,而bean name可以使用特殊字符,并且可以命名多个,例如<bean name="test1,test2,test3" class="cn.test"/> ? 建议开发时,使用bean id,最好不要使用bean name ? spring配置中property作为bean的属性。也就是指一个类中的成员。同时这个成员必须有get和set方法。 ? property有这样的常见用法: (1)配置数据源,这里使用el表达式 name="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> ="url" value="${jdbc_url}"/> ="username"="${jdbc_username}"="password"="${jdbc_password}"="validationQuery"="${validationQuery}"/> > (2)引用其他对象 <!-- 自定义Realm --> id="userRealm"="com.blog.shiro.UserRealm"/> 安全管理器 --> ="securityManager"="org.apache.shiro.web.mgt.DefaultWebSecurityManager"> ="realm" ref="userRealm"/> > (3)使用map list set props等方式 props: 配置session工厂="sessionFactory"="org.springframework.orm.hibernate4.LocalSessionFactoryBean"="dataSource" ="packagesToScan"="com.ssh.entity" ="hibernateProperties"> props> prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}prop> hibernate根据实体自动生成数据库表--> ="hibernate.dialect">${hibernate.dialect}> 指定数据库方言="hibernate.show_sql">${hibernate.show_sql}> 在控制台显示执行的数据库操作语句="hibernate.format_sql">${hibernate.format_sql}在控制台显示执行的数据哭操作语句(格式)--> property> > ? map: ="filters"util:mapentry ="shiroUserFilter" value-ref="shiroUserFilter"/> ="shiroFormFilter"="shiroFormFilter"> ? list: ="list"> list> value>Hello World!ref local="mysql"/> //表示在本配置文件中查找bean。后面有详细讲解 > > ? set: ="set"set/> > ? ? <property name="sleepTime" value="${app.dispatcher.sleepTime}" /> ?//从外部的property文件中用el表达式获取值 <property name="sleepTime" value="333" /> ?//直接在赋值 <property name="playerDao" ref="playerDao" /> ? ?引用其他bean对象。 ?ref的值是其他bean的id名 五、运行main方法打印如下结果 ? (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |