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【设计模式】【用DOM4J模拟spring实现简单工厂】
package lee;
/**
* Description:
* <br/>网站: <a href="https://www.crazyit.org">疯狂Java联盟</a>
* <br/>Copyright (C), 2001-2012, Yeeku.H.Lee
* <br/>This program is protected by copyright laws.
* <br/>Program Name:
* <br/>Date:
* @author Yeeku.H.Lee kongyeeku@163.com
* @version 1.0
*/
public interface Output
{
//接口里定义的属性只能是常量
int MAX_CACHE_LINE = 50;
//接口里定义的只能是public的抽象实例方法
void out();
void getData(String msg);
}
package lee;
/**
* Description:
* <br/>网站: <a href="https://www.crazyit.org">疯狂Java联盟</a>
* <br/>Copyright (C), 2001-2012, Yeeku.H.Lee
* <br/>This program is protected by copyright laws.
* <br/>Program Name:
* <br/>Date:
* @author Yeeku.H.Lee kongyeeku@163.com
* @version 1.0
*/
//让Printer类实现Output
public class Printer implements Output
{
private String[] printData = new String[MAX_CACHE_LINE];
//用以记录当前需打印的作业数
private int dataNum = 0;
public void out()
{
//只要还有作业，继续打印
while(dataNum > 0)
{
System.out.println("打印机打印：" + printData[0]);
//把作业队列整体前移一位，并将剩下的作业数减1
System.arraycopy(printData , 1, printData, 0, --dataNum);
}
}
public void getData(String msg)
{
if (dataNum >= MAX_CACHE_LINE)
{
System.out.println("输出队列已满，添加失败");
}
else
{
//把打印数据添加到队列里，已保存数据的数量加1。
printData[dataNum++] = msg;
}
}
}
package lee;
/**
* Description:
* <br/>网站: <a href="https://www.crazyit.org">疯狂Java联盟</a>
* <br/>Copyright (C), 2001-2012, Yeeku.H.Lee
* <br/>This program is protected by copyright laws.
* <br/>Program Name:
* <br/>Date:
* @author Yeeku.H.Lee kongyeeku@163.com
* @version 1.0
*/
public class BetterPrinter implements Output
{
private String[] printData = new String[MAX_CACHE_LINE * 2];
//用以记录当前需打印的作业数
private int dataNum = 0;
public void out()
{
//只要还有作业，继续打印
while(dataNum > 0)
{
System.out.println("高速打印机正在打印：" + printData[0]);
//把作业队列整体前移一位，并将剩下的作业数减1
System.arraycopy(printData , 1, printData, 0, --dataNum);
}
}
public void getData(String msg)
{
if (dataNum >= MAX_CACHE_LINE * 2)
{
System.out.println("输出队列已满，添加失败");
}
else
{
//把打印数据添加到队列里，已保存数据的数量加1。
printData[dataNum++] = msg;
}
}
}
package lee;
/**
* Description:
* <br/>网站: <a href="https://www.crazyit.org">疯狂Java联盟</a>
* <br/>Copyright (C), 2001-2012, Yeeku.H.Lee
* <br/>This program is protected by copyright laws.
* <br/>Program Name:
* <br/>Date:
* @author Yeeku.H.Lee kongyeeku@163.com
* @version 1.0
*/
public class BetterPrinter implements Output
{
private String[] printData = new String[MAX_CACHE_LINE * 2];
//用以记录当前需打印的作业数
private int dataNum = 0;
public void out()
{
//只要还有作业，继续打印
while(dataNum > 0)
{
System.out.println("高速打印机正在打印：" + printData[0]);
//把作业队列整体前移一位，并将剩下的作业数减1
System.arraycopy(printData , 1, printData, 0, --dataNum);
}
}
public void getData(String msg)
{
if (dataNum >= MAX_CACHE_LINE * 2)
{
System.out.println("输出队列已满，添加失败");
}
else
{
//把打印数据添加到队列里，已保存数据的数量加1。
printData[dataNum++] = msg;
}
}
}
package lee;
import org.crazyit.ioc.*;
/**
* Description:
* <br/>网站: <a href="https://www.crazyit.org">疯狂Java联盟</a>
* <br/>Copyright (C), 2001-2012, Yeeku.H.Lee
* <br/>This program is protected by copyright laws.
* <br/>Program Name:
* <br/>Date:
* @author Yeeku.H.Lee kongyeeku@163.com
* @version 1.0
*/
public class IoCTest
{
public static void main(String[] args)
throws Exception
{
//创建IoC容器
ApplicationContext ctx =
new YeekuXmlApplicationContext("bean.xml");
//从IoC容器中取出computer Bean
Computer c = (Computer)ctx.getBean("computer");
//测试Computer对象
c.keyIn("轻量级Java EE企业应用实战");
c.keyIn("疯狂Java讲义");
c.print();
System.out.println(ctx.getBean("now"));
}
}
<?xml version="1.0" encoding="GBK"?> <beans> <bean > <!-- 为name属性注入普通属性值 --> <property name="name" value="李刚的电脑"/> <!-- 为out属性注入普通属性值 --> <property name="out" ref="betterPrinter"/> </bean> <!-- 配置两个Bean实例 --> <bean /> <bean /> <!-- 配置一个prototype行为的Bean实例 --> <bean scope="prototype"/> <!--①--> </beans>
<?xml version="1.0" encoding="GBK"?> <beans> <bean > <!-- 为name属性注入普通属性值 --> <property name="name" value="李刚的电脑"/> <!-- 为out属性注入普通属性值 --> <property name="out" ref="betterPrinter"/> </bean> <!-- 配置两个Bean实例 --> <bean /> <bean /> <!-- 配置一个prototype行为的Bean实例 --> <bean scope="prototype"/> <!--①--> </beans>
package org.crazyit.ioc;
import java.lang.reflect.*;
import java.util.*;
import java.io.*;
import org.dom4j.*;
import org.dom4j.io.*;
/**
* Description:
* <br/>网站: <a href="https://www.crazyit.org">疯狂Java联盟</a>
* <br/>Copyright (C), 2001-2012, Yeeku.H.Lee
* <br/>This program is protected by copyright laws.
* <br/>Program Name:
* <br/>Date:
* @author Yeeku.H.Lee kongyeeku@163.com
* @version 1.0
*/
public class YeekuXmlApplicationContext
implements ApplicationContext
{
//保存容器中所有单例模式的Bean实例
private Map<String , Object> objPool
= Collections.synchronizedMap(new HashMap<String , Object>());
//保存配置文件对应的Document对象
private Document doc;
//保存配置文件里的根元素
private Element root;
public YeekuXmlApplicationContext(String filePath)
throws Exception
{
SAXReader reader = new SAXReader();
doc = reader.read(new File(filePath));
root = doc.getRootElement();
initPool();
initProp();
}
public Object getBean(String name)
throws Exception
{
Object target = objPool.get(name);
//对于singleton Bean，容器已经初始化了所有Bean实例
if (target.getClass() != String.class)
{
return target;
}
else
{
String clazz = (String)target;
//对于prototype并未注入属性值
return Class.forName(clazz).newInstance();
}
}
//初始化容器中所有singleton Bean
private void initPool()
throws Exception
{
//遍历配置文件里的每个<bean.../>元素
for (Object obj : root.elements())
{
Element beanEle = (Element)obj;
//取得<bean.../>元素的id属性
String beanId = beanEle.attributeValue("id");
//取得<bean.../>元素的class属性
String beanClazz = beanEle.attributeValue("class");
//取得<bean.../>元素的scope属性
String beanScope = beanEle.attributeValue("scope");
//如果<bean.../>元素的scope属性不存在，或为singleton
if (beanScope == null ||
beanScope.equals("singleton"))
{
//以默认构造器创建Bean实例，并将其放入objPool中
objPool.put(beanId , Class.forName(beanClazz).newInstance());
}
else
{
//对于非singlton Bean，存放该Bean实现类的类名。
objPool.put(beanId , beanClazz);
}
}
}
//初始化容器中singleton Bean的属性
private void initProp()
throws Exception
{
//遍历配置文件里的每个<bean.../>元素
for (Object obj : root.elements())
{
Element beanEle = (Element)obj;
//取得<bean.../>元素的id属性
String beanId = beanEle.attributeValue("id");
//取得<bean.../>元素的scope属性
String beanScope = beanEle.attributeValue("scope");
//如果<bean.../>元素的scope属性不存在，或为singleton
if (beanScope == null ||
beanScope.equals("singleton"))
{
//取出objPool的指定的Bean实例
Object bean = objPool.get(beanId);
//遍历<bean.../>元素的每个<property.../>子元素
for (Object prop : beanEle.elements())
{
Element propEle = (Element)prop;
//取得<property.../>元素的name属性
String propName = propEle.attributeValue("name");
//取得<property.../>元素的value属性
String propValue = propEle.attributeValue("value");
//取得<property.../>元素的ref属性
String propRef = propEle.attributeValue("ref");
//将属性名的首字母大写
String propNameCamelize = propName.substring(0 , 1).toUpperCase()
+ propName.substring(1 , propName.length());
//如果<property.../>元素的value属性值存在
if (propValue != null && propValue.length() > 0)
{
//获取设值注入所需的setter方法
Method setter = bean.getClass().getMethod(
"set" + propNameCamelize , String.class);
//执行setter注入
setter.invoke(bean , propValue);
}
if (propRef != null && propRef.length() > 0)
{
//取得需要被依赖注入的Bean实例
Object target = objPool.get(propRef);
//objPool池中不存在指定Bean实例
if (target == null)
{
//此处还应处理Singleton Bean依赖prototype Bean的情形
}
//定义设值注入所需的setter方法
Method setter = null;
//遍历target对象所所实现的所有接口
for (Class superInterface : target.getClass().getInterfaces())
{
try
{
//获取设值注入所需的setter方法
setter = bean.getClass().getMethod(
"set" + propNameCamelize , superInterface);
//如果成功取得该接口对应的方法，直接跳出循环
break;
}
catch (NoSuchMethodException ex)
{
//如果没有找到对应的setter方法，继续下次循环
continue;
}
}
//如果setter方法依然为null，
//则直接取得target实现类对应的setter方法
if (setter == null)
{
setter = bean.getClass().getMethod(
"set" + propNameCamelize , target.getClass());
}
//执行setter注入
setter.invoke(bean , target);
}
}
}
}
}
}
最后更新：2017-04-04 07:03:36