通过代码入门Spring①何为IOC

HelloWord.java

package cn.podger.spring.demo1;

public class HelloWorld {
private String strSomeThingSay = "helloWorld!";

public String getSomeThingSay(){
	System.out.println(strSomeThingSay);
	return strSomeThingSay;
}

public void saySomeThing(String str){
	strSomeThingSay = str;
	System.out.println(strSomeThingSay);
}

}

Student.java

package cn.podger.spring.demo1;

import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

@Component
@Scope("prototype")
public class Student {
private String name;
private String id;
private int age = 100;
public String getName() {
	return name;
}
public void setName(String name) {
	this.name = name;
}
public String getId() {
	return id;
}
public void setId(String id) {
	this.id = id;
}
public int getAge() {
	return age;
}
public void setAge(int age) {
	this.age = age;
}

} 

App.java

package cn.podger.spring.demo1;

import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.FileSystemResource;

/**
 * Spring  IOC 功能演示  程序中的之间的关系，不用代码控制，而完全是由容器来控制
 *
 */
public class App 
{
    public static void main( String[] args )
    {  
    	/**
    	 * FileSystemResource 搜索的是项目工作目录下的地址  本案例为  /spring-demo1文件夹下
    	 */
    	XmlBeanFactory xbf = new XmlBeanFactory(new FileSystemResource("applicationContext.xml"));
    	HelloWorld hw1 = (HelloWorld)xbf.getBean("helloWorld");
    	hw1.getSomeThingSay();
    	hw1.saySomeThing("Spring 你好！");
    	
    	HelloWorld hw2 = (HelloWorld)xbf.getBean("helloWorld");
    	hw2.getSomeThingSay();
    	/**
    	 * 输出结果为
    	 * helloWorld!
         * Spring 你好！
         * Spring 你好！
    	 * 以下关于bean的解析说明了，默认是单例模式，所以以上结果也就能理解了.
    	 * The scope of this bean: typically "singleton" (one shared instance, which will be returned by all calls to 
         *  getBean with the given id), or "prototype" (independent instance resulting from each call to getBean). 
         *  Default is "singleton". Singletons are most commonly used, and are ideal for multi-threaded service 
         *  objects. Further scopes, such as "request" or "session", might be supported by extended bean 
         *  factories (e.g. in a web environment). Note: This attribute will not be inherited by child bean 
         *  definitions. Hence, it needs to be specified per concrete bean definition. Inner bean definitions inherit 
         *  the singleton status of their containing bean definition, unless explicitly specified: The inner bean will 
         *  be a singleton if the containing bean is a singleton, and a prototype if the containing bean has any 
         *  other scope.
    	 */
    	
    	/**
    	 * 在applicationContext 修改bean为以下
    	 * 	<bean id="helloWorld"  scope="prototype" class="cn.podger.spring.demo1.HelloWorld"></bean>
    	 * 也就是添加了个scope="prototype"属性  意思为每次getBean 为new 对象
    	 * 修改后的结果为
    	 * helloWorld!
         * Spring 你好！
         * helloWorld!
         * 根据以上的解析这输出毋容置疑.
    	 */
    	
    	/**
    	 * 另外还有种通过spring注解方法加载的方法
    	 * 在配置文件中添加以下内容
    	 * <context:component-scan base-package="cn.podger.spring.demo1"></context:component-scan>	
    	 * 意思是扫描@component加载bean
    	 * 同<bean id="" class=""> </bean> 的意思
    	 * 代码如下
    	 */
    	/**
    	 *Student student = (Student)xbf.getBean("student");
    	 *System.out.println(student.getAge());
    	 */
    }
}

项目下载http://download.csdn.net/detail/bojie5744/9541005