做电子政务 网站/灰色词快速排名接单
IOC容器:
按照我的理解为:我们需要什么都交给容器来实现 比如原先我们需要得到就要 new 一个实例,有了容器需要实例就让容器创建,需要变量,属性就让容器注入。
简单的接口实例:
package com.interface1;public interface OneInterface {public void say(String arg);
}
++++++++++++++++++++++++++++++++
package com.interface1;/** OneInterface实现类*/
public class OneInterfaceImpl implements OneInterface {public void say(String arg) {System.out.println("ServiceImpl say: " + arg);}}
++++++++++++++++++++++++++
package com.interface1;public class Main {public static void main(String[] args){/** 简单的面向接口编程:把接口实现类赋值给接口的声明:oif*/OneInterface oif=new OneInterfaceImpl();oif.say("Hello Spring");}
}
++++++++++++++++++++++++++
使用IOC容器来实现(也是上面的接口和接口实现类)
需要junit相关jar包以及spring相关jar包。。。。。。。
工具类:
package com.imooc.test.base;import org.junit.After;
import org.junit.Before;
import org.springframework.beans.BeansException;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.util.StringUtils;public class UnitTestBase {private ClassPathXmlApplicationContext context;private String springXmlpath;public UnitTestBase() {}public UnitTestBase(String springXmlpath) {this.springXmlpath = springXmlpath;}@Beforepublic void before() {if (StringUtils.isEmpty(springXmlpath)) {springXmlpath = "classpath*:spring-*.xml";}try {context = new ClassPathXmlApplicationContext(springXmlpath.split("[,\\s]+"));context.start();} catch (BeansException e) {e.printStackTrace();}}@Afterpublic void after() {context.destroy();}@SuppressWarnings("unchecked")protected <T extends Object> T getBean(String beanId) {try {return (T)context.getBean(beanId);} catch (BeansException e) {e.printStackTrace();return null;}}protected <T extends Object> T getBean(Class<T> clazz) {try {return context.getBean(clazz);} catch (BeansException e) {e.printStackTrace();return null;}}}
package com.interface1;import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;import com.imooc.test.base.UnitTestBase;@RunWith(BlockJUnit4ClassRunner.class)
public class MainTestJunit extends UnitTestBase{public MainTestJunit() {super("classpath*:spring-ioc.xml");}@Testpublic void testSay() {OneInterface oneInterface = super.getBean("oneInterface");oneInterface.say("Hello Boy");}}
Spring配置文件:(spring-ioc.xml)
<?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/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd" ><bean id="oneInterface" class="com.interface1.OneInterfaceImpl"></bean></beans>
如果像上面的操作似乎比一般的方法更加麻烦
当多个接口有多个对象的时候 就需要一个一个的new了 就很麻烦:
定义两个接口 两个接口实现类
其中InjectionDao为InjectionServiceImpl 的属性
package com.inner;public interface InjectionDao {public void save(String arg);
}
package com.inner;public class InjectionDaoImpl implements InjectionDao {@Overridepublic void save(String arg) {// TODO Auto-generated method stubSystem.out.println("模拟数据库操作:保存数据"+arg);}}
package com.inner;public interface InjectionService {public void save(String arg);
}
如何给InjectionServiceImpl注入值 :两种方法
1:设置注入: propety name 为变量名 要为这个变量设置set方法
2:构造器注入: 需要显式的构造器 构造器的参数名和name后的一致
package com.inner;public class InjectionServiceImpl implements InjectionService{private InjectionDao injectionDAO;//设值注入public void setInjectionDAO(InjectionDao injectionDAO) {this.injectionDAO = injectionDAO;}//构造注入:public InjectionServiceImpl(InjectionDao injectionDAO){this.injectionDAO = injectionDAO;}@Overridepublic void save(String arg) {System.out.println("模拟业务操作:保存数据"+arg);arg=arg+":"+arg.hashCode();injectionDAO.save(arg);}}
+++++++++++++++++++++++++++++++
两种方式在配置文件中得配置:
spring-injection.xml
<?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/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd" ><!-- <bean id="injectionService1" class="com.inner.InjectionServiceImpl"> <property name="injectionDAO" ref="injectionDAO"></property></bean>--><bean id="injectionService2" class="com.inner.InjectionServiceImpl"><constructor-arg name="injectionDAO" ref="injectionDAO"></constructor-arg></bean><bean id="injectionDAO" class="com.inner.InjectionDaoImpl"></bean></beans>
测试类:
package com.inner;import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;import com.imooc.test.base.UnitTestBase;@RunWith(BlockJUnit4ClassRunner.class)
public class TestInjection extends UnitTestBase{public TestInjection() {super("classpath*:spring-injection.xml");}// @Test
// //设值植入
// public void testSetter() {
// InjectionService service = super.getBean("injectionService1");
// service.save("这是要保存的数据");
// }//构造植入:@Testpublic void testConstor(){InjectionService service = super.getBean("injectionService2");service.save("这是要保存的数据");}
}
总结:
其中 id为我理解的为该class=“”中类的实例 保存在IOC中 而
name=”injectionDAO” ref=”injectionDAO”>中得name的值为id的属性名 ref的值为<bean id="injectionDAO" class="com.inner.InjectionDaoImpl"></bean>
的id值
在xml文件中的类都是实现类 而在InjectionServiceImpl 的实现类中都是接口属性 接口属性使用的该接口实现类来实例化的
问题:
不懂public TestInjection() {
super("classpath*:spring-injection.xml");
}
中的super的classpath加星号和不加星号的区别