Spring从IOC（Inversion of Control：控制反转）开始

引用

有的时候变的茫然了，不知道前方的路该怎么走；有的时候变的颓废了，不知道从前的你过的还是否开心；有的时候理解和包容同在，我愿意做一个更出色的男人。辗转反侧通往成功的大门还需要多少力气敲开，于是静下心来回顾与内省。

Spring是不是个好东西我不知道，但当大家都在推崇的时候，那么即使再默然，也应该警醒，即便大家不一定对，但天若塌下来，那大家也会一起陪着，你并不孤单

ioc有两种实现方式

第一种xml的方式实现

首先建个基类：

public abstract class People { protected int id; public int getId() { return id; } public void setId(int id) { this.id = id; } }

再然后创建teacher类

public class Teacher extends People { private String name; private String tNo; public String getName() { return name; } public void setName(String name) { this.name = name; } public String gettNo() { return tNo; } public void settNo(String tNo) { this.tNo = tNo; } @Override public String toString() { return "id = "+id +" name = "+ name +" tNo = " + tNo; } }

在src下面创建beans.xml 文件

<?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-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <!--相当于 Teacher teacher = new Teacher() scope 为 prototype多例，默认为单例--> <bean id="teacher" class="com.model.xml.Teacher" scope="prototype"> <property name="id" value="10"/> <property name="name" value="teacher"/> <property name="tNo" value="t10"/> </bean> </beans>

编写测试代码Test.java

public class Test { private BeanFactory factory = new ClassPathXmlApplicationContext("beans.xml"); @org.junit.Test public void testTeacherXml(){ Teacher teacher = factory.getBean("teacher",Teacher.class); System.out.println(teacher.toString()); } }

输出信息：

id = 10 name = teacher tNo = t10

再来创建一个

创建User类

public class User { private int id; private String userName; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } @Override public String toString() { return "id = " + id +" userName = " + userName; } }

创建UserAction

public class UserAction { private int id; private User user; public int getId() { return id; } public void setId(int id) { this.id = id; } public User getUser() { return user; } public void setUser(User user) { this.user = user; } @Override public String toString() { return "userAction.id = " + id + " " + user.toString(); } }

因为UserAction持有了User对象那么看下beans.xml是怎么配置的

<?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-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <bean id="user" class="com.model.xml.User"> <property name="id" value="2"/> <property name="userName" value="haha"/> </bean> <!--注入对象使用ref 注入值使用value--> <bean id="userAction" class="com.model.xml.UserAction" scope="prototype"> <property name="id" value="12"/> <property name="user" ref="user"/> </bean> </beans>

编写测试代码：

public class Test { private BeanFactory factory = new ClassPathXmlApplicationContext("beans.xml"); @org.junit.Test public void testUserActionXml(){ UserAction userAction = factory.getBean("userAction",UserAction.class); System.out.println(userAction.toString()); } }

输出信息：

userAction.id = 12 id = 2 userName = haha

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第二种采用注解的方式实现

注解的标注有以下几种

@Component、@Repository、@Service、@Controller、@Autowired、@Resource

其中代表的含义如下

@Component泛指组件，可以在一些POJO上使用这个注解进行标注

@Repository用于标注数据访问组件，即DAO组件

@Service用于标注业务层组件

@Controller用于标注控制层组件，如Struts中的Action

@Autowired Spring提供装配

@Resource j2EE提供

接下来先创建Student类使用Component注解

@Component public class Student extends People { private String name; private String sNo; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getsNo() { return sNo; } public void setsNo(String sNo) { this.sNo = sNo; } @Override public String toString() { return "id = "+id +" name = "+ name +" sNo = " + sNo; } }

在beans.xml中配置

<?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-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <!--打开Spring的Annoation支持--> <context:annotation-config/> <!--扫描model包下面以及子包下面的所有类--> <context:component-scan base-package="com.model.**"/> </beans>

编写Test.java测试代码：

public class Test { private BeanFactory factory = new ClassPathXmlApplicationContext("beans.xml"); @org.junit.Test public void testAnno(){ Student student = factory.getBean("student",Student.class); student.setId(20); student.setName("teacher"); student.setsNo("s20"); System.out.println(student.toString()); } }

输出信息：

id = 20 name = teacher sNo = s20

DEMO链接