1.xml文件：
<?xml version="1.0" encoding="UTF-8"?>
<application>
<beans>
<bean name="obj1" class="com.jzy.xml.class1">
<attribute name="attr1">value1</attribute>
</bean>
<bean name="obj2" class="com.jzy.xml.class2">
<attribute name="attr1">value1</attribute>
</bean>
</beans>
</application>2.自定義異常類：
package com.jzy.ioc;
public class BeanNotFindException extends RuntimeException{
public BeanNotFindException(){
super("你要查找的bean不存在！");
}
}3.屬性保存類：
package com.jzy.ioc;
import java.util.Hashtable;
public class IocBeanInfo {
String className="";
Hashtable attrMapping=new Hashtable();
}4.主類（xml解析，內省，反射）
package com.jzy.ioc;
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.util.Hashtable;
import javax.sound.midi.MidiDevice.Info;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class IocFactory {
Hashtable beanMapping = new Hashtable();
public IocFactory() {
try {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); // 定義工廠
// API，使應用程序能夠從
// XML
// 文檔獲取生成
// DOM
// 對象樹的解析器。
dbf.setNamespaceAware(true); // 指示是否將工廠配置爲生成具有感知名稱空間功能的解析器。
DocumentBuilder db = dbf.newDocumentBuilder(); // 定義 API， 使其從 XML
// 文檔獲取 DOM 文檔實例
Document doc = db.parse("myclass.xml"); //xml文件在根路徑下
NodeList beansList = doc.getElementsByTagName("beans"); //獲取beans節點集合
for (int i = 0; i < beansList.getLength(); i++) {
Node beansNode = beansList.item(i); //獲取具體的beans節點
NodeList beanList = beansNode.getChildNodes(); //獲取具體的beans節點的子節點的集合（bean）
for (int j = 0; j < beanList.getLength(); j++) {
Node beanNode = beanList.item(j); //獲取具體的bean節點
if (beanNode.getNodeName().equals("bean")) { //因爲xml會將空格，換行也當成節點，所以要判斷
IocBeanInfo info = new IocBeanInfo();
String beanName = ""; //保存bean節點屬性中name的值
NamedNodeMap beanNodeMap = beanNode.getAttributes();
Node beanNameAttr = beanNodeMap.getNamedItem("name");
beanName = beanNameAttr.getNodeValue(); //保存屬性名
Node beanClassAttr = beanNodeMap.getNamedItem("class");
info.className = beanClassAttr.getNodeValue(); //保存類名
NodeList attributeList = beanNode.getChildNodes();
for (int m = 0; m < attributeList.getLength(); m++) {
Node attributeNode = attributeList.item(m);
if (attributeNode.getNodeName().equals("attribute")) {
String attrValue = "";
NamedNodeMap attrNodeMap = attributeNode
.getAttributes();
Node attributeName = attrNodeMap
.getNamedItem("name");
attrValue = attributeNode.getTextContent()
.trim();
// System.out.println("attrName: "+attributeName.getNodeName());
// System.out.println("attrValue: "+attributeNode.getTextContent().trim());
info.attrMapping
.put(attributeName.getNodeValue(),
attrValue);
}
}
beanMapping.put(beanName, info);
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public Object getBean(String baseName) {
if (beanMapping.get(baseName) != null) {
IocBeanInfo info = (IocBeanInfo) beanMapping.get(baseName);
try {
Class cl = Class.forName(info.className); //獲取類描述信息
Object obj = cl.newInstance(); //創建對象
BeanInfo binfo = Introspector.getBeanInfo(cl); //內省獲取屬性信息
PropertyDescriptor[] pds = binfo.getPropertyDescriptors();
for (PropertyDescriptor pd : pds) {
String pname = pd.getName();
if (info.attrMapping.get(pname) != null) {
Method propertyWriteMethod = pd.getWriteMethod();
Class[] argsTypes = propertyWriteMethod
.getParameterTypes();
String argTypeString = argsTypes[0].getCanonicalName();
String attValue = info.attrMapping.get(pname)
.toString();
if (argTypeString.equals("int")) {
// 利用反射調用該屬性的set方法
propertyWriteMethod.invoke(obj,
new Object[] { new Integer(attValue) });
} else if (argTypeString.equals("boolean")) {
propertyWriteMethod.invoke(obj,
new Object[] { new Boolean(attValue) });
} else if (argTypeString.equals("char")) {
propertyWriteMethod.invoke(
obj,
new Object[] { new Character(attValue
.charAt(0)) });
} else if (argTypeString.equals("byte")) {
propertyWriteMethod.invoke(obj,
new Object[] { new Byte(attValue) });
} else if (argTypeString.equals("short")) {
propertyWriteMethod.invoke(obj,
new Object[] { new Short(attValue) });
} else if (argTypeString.equals("long")) {
propertyWriteMethod.invoke(obj,
new Object[] { new Long(attValue) });
} else if (argTypeString.equals("double")) {
propertyWriteMethod.invoke(obj,
new Object[] { new Double(attValue) });
} else if (argTypeString.equals("float")) {
propertyWriteMethod.invoke(obj,
new Object[] { new Float(attValue) });
} else if (argTypeString.equals("java.lang.String")) {
propertyWriteMethod.invoke(obj,
new Object[] { attValue });
} else {
Object refObj = getBean(attValue);
propertyWriteMethod.invoke(obj,
new Object[] { refObj });
}
}
}
return obj;
} catch (Exception ex) {
ex.printStackTrace();
}
} else {
throw new BeanNotFindException();
}
return null;
}
public static void main(String[] args){
IocFactory factory=new IocFactory();
IocBeanInfo info=(IocBeanInfo)factory.beanMapping.get("obj1");
System.out.println(info.className);
}
}