<?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"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
<!-- 注入方式一，直接使用类全名注入，属性必须有相应的set方法才可以注入成功，否则会失败 -->
<!-- 假如没有a属性，但是有setA方法，也可以配置a的property和value，但这样做并没有什么意义 -->
<bean id="userDao1" class="com.colorlight.spring.UserDaoImpl">
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test"></property>
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="username" value="root"></property>
<property name="password" value="1"></property>
</bean>
<!-- 注入方式二：使用静态的工厂方法创建实例，必须配置相应的工厂类和工厂方法 -->
<bean id="userDao2" class="com.colorlight.spring.StaticDaoFactory"
factory-method="createUserDaoInstance">
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test"></property>
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="username" value="root"></property>
<property name="password" value="2"></property>
</bean>
<!-- 注入方式三：使用非静态的工厂方法创建实例，必须先生成工厂的实例 -->
<bean id="daoFactory" class="com.colorlight.spring.NonStaticDaoFactory">
</bean>
<bean id="userDao3" factory-bean="daoFactory" factory-method="createUserDao">
<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test"></property>
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="username" value="root"></property>
<property name="password" value="3"></property>
</bean>
<!-- 注入方式四：使用构造函数注入 -->
<bean id="userDao4" class="com.colorlight.spring.UserDaoImpl">
<constructor-arg value="jdbc:mysql://localhost:3306/test" />
<constructor-arg value="com.mysql.jdbc.Driver" />
<constructor-arg value="root" />
<constructor-arg value="4" />
</bean>
</beans>
接口UserDao:
package com.colorlight.spring;
public interface UserDao {
void printInfo();
}
实现类UserDaoImpl：
package com.colorlight.spring;
public class UserDaoImpl implements UserDao {
private String jdbcUrl;
private String driverClass;
private String username;
private String password;
public UserDaoImpl(){
}
public UserDaoImpl(String url, String driver, String name, String pw) {
this.jdbcUrl = url;
this.driverClass = driver;
this.username = name;
this.password = pw;
}
public void printInfo() {
System.out.println("jdbcUrl = " + jdbcUrl);
System.out.println("driverClass = " + driverClass);
System.out.println("username = " + username);
System.out.println("password = " + password);
}
public String getJdbcUrl() {
return jdbcUrl;
}
public void setJdbcUrl(String jdbcUrl) {
this.jdbcUrl = jdbcUrl;
}
public String getDriverClass() {
return driverClass;
}
public void setDriverClass(String driverClass) {
this.driverClass = driverClass;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
静态方法类：
package com.colorlight.spring;
public class StaticDaoFactory {
public static UserDao createUserDaoInstance(){
return new UserDaoImpl();
}
}
非静态方法类：
package com.colorlight.spring;
public class NonStaticDaoFactory {
public UserDao createUserDao() {
return new UserDaoImpl();
}
}
测试类：
package com.colorlight.springscope;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainTest {
ApplicationContext ac = new ClassPathXmlApplicationContext(
"applicationContext.xml", this.getClass());
// 单例
@Test
public void test1() {
System.out.println("在getBean()调用之前");
User user1 = (User) ac.getBean("user1");
User user2 = (User) ac.getBean("user1");
System.out.println(user1 != null);
System.out.println(user1 == user2);
}
// 多例
@Test
public void test2() {
System.out.println("在getBean()调用之前");
User user1 = (User) ac.getBean("user2");
User user2 = (User) ac.getBean("user2");
System.out.println(user1 != null);
System.out.println(user1 == user2);
}
}