beanfactory.java

JAVA的IOC简单实现

package com.zj.ioc.di.imp;

import java.io.File;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.dom4j.Attribute;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.ElementHandler;
import org.dom4j.ElementPath;
import org.dom4j.io.SAXReader;

public class BeanFactory {
	private Map<String, Object> beanMap = new HashMap<String, Object>();

	public void init(String xmlUri) throws Exception {
		SAXReader saxReader = new SAXReader();
		File file = new File(xmlUri);
		try {
			saxReader.addHandler("/beans/bean", new BeanHandler());
			saxReader.read(file);

		} catch (DocumentException e) {
			System.out.println(e.getMessage());
		}
	}

	public Object getBean(String beanId) {
		Object obj = beanMap.get(beanId);
		return obj;
	}

	private void setFieldValue(Object obj, Field field, String value) {
		String fieldType = field.getType().getSimpleName();
		try {
			if (fieldType.equals("int"))
				field.setInt(obj, new Integer(value));
			else if (fieldType.equals("float"))
				field.setFloat(obj, new Float(value));
			else if (fieldType.equals("boolean"))
				field.setBoolean(obj, new Boolean(value));
			else if (fieldType.equals("char"))
				field.setChar(obj, value.charAt(0));
			else if (fieldType.equals("double"))
				field.setDouble(obj, new Double(value));
			else if (fieldType.equals("long"))
				field.setLong(obj, new Long(value));
			else
				field.set(obj, value);
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
	}

	private void setFieldValue(Object obj, Field field, List<String> value) {
		try {
			field.set(obj, value);
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
	}

	private void setFieldValue(Object obj, Field field, Set<String> value) {
		try {
			field.set(obj, value);
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
	}

	private void setFieldValue(Object obj, Field field,
			Map<String, String> value) {
		try {
			field.set(obj, value);
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
	}

	private void setFieldValue(Object obj, Field field, Object bean) {
		try {
			field.set(obj, bean);
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
	}

	private class BeanHandler implements ElementHandler {
		Object obj = null;

		public void onStart(ElementPath path) {
			Element beanElement = path.getCurrent();
			Attribute classAttribute = beanElement.attribute("class");

			Class<?> bean = null;
			try {
				bean = Class.forName(classAttribute.getText());
			} catch (ClassNotFoundException e) {
				e.printStackTrace();
			}
			Field fields[] = bean.getDeclaredFields();
			Map<String, Field> mapField = new HashMap<String, Field>();
			for (Field field : fields)
				mapField.put(field.getName(), field);
			try {
				obj = bean.newInstance();
			} catch (InstantiationException e) {
				e.printStackTrace();
			} catch (IllegalAccessException e) {
				e.printStackTrace();
			}

			path.addHandler("property", new PropertyHandler(mapField, obj));
		}

		public void onEnd(ElementPath path) {
			Element beanElement = path.getCurrent();
			Attribute idAttribute = beanElement.attribute("id");
			beanMap.put(idAttribute.getText(), obj);
			path.removeHandler("property");
		}
	}

	private class PropertyHandler implements ElementHandler {
		Map<String, Field> mapField;
		Object obj;

		public PropertyHandler(Map<String, Field> mapField, Object obj) {
			this.mapField = mapField;
			this.obj = obj;
		}

		public void onStart(ElementPath path) {
			Element propertyElement = path.getCurrent();
			Attribute nameAttribute = propertyElement.attribute("name");
			path.addHandler("value", new ValueHandler(mapField, obj,
					nameAttribute));
			path.addHandler("list", new ListHandler(mapField, obj,
					nameAttribute));
			path.addHandler("set", new SetHandler(mapField, obj,
					nameAttribute));
			path.addHandler("map", new MapHandler(mapField, obj,
					nameAttribute));
			path.addHandler("ref", new RefHandler(mapField, obj,
					nameAttribute));
		}

		public void onEnd(ElementPath path) {
			path.removeHandler("value");
			path.removeHandler("list");
			path.removeHandler("set");
			path.removeHandler("map");
			path.removeHandler("ref");
		}
	}

	private class ValueHandler implements ElementHandler {
		Map<String, Field> mapField;
		Object obj;
		Attribute nameAttribute;

		public ValueHandler(Map<String, Field> mapField, Object obj,
				Attribute nameAttribute) {
			this.mapField = mapField;
			this.obj = obj;
			this.nameAttribute = nameAttribute;
		}

		public void onStart(ElementPath path) {

		}

		public void onEnd(ElementPath path) {
			Element valueElement = path.getCurrent();
			String strValue = null;
			strValue = valueElement.getText();

			Field tmpField = mapField.get(nameAttribute.getValue());
			if (tmpField != null) {
				tmpField.setAccessible(true);
				setFieldValue(obj, tmpField, strValue);
			}
		}
	}

	private class ListHandler implements ElementHandler {
		Map<String, Field> mapField;
		Object obj;
		Attribute nameAttribute;
		List<String> list;

		public ListHandler(Map<String, Field> mapField, Object obj,
				Attribute nameAttribute) {
			this.mapField = mapField;
			this.obj = obj;
			this.nameAttribute = nameAttribute;
		}

		public void onStart(ElementPath path) {
			list = new ArrayList<String>();
			path.addHandler("value", new ListValueHandler(list));
		}

		public void onEnd(ElementPath path) {
			path.removeHandler("value");
			Field tmpField = mapField.get(nameAttribute.getValue());
			if (tmpField != null) {
				tmpField.setAccessible(true);
				setFieldValue(obj, tmpField, list);
			}
		}
	}

	private class ListValueHandler implements ElementHandler {
		List<String> list;

		public ListValueHandler(List<String> list) {
			this.list = list;
		}

		public void onStart(ElementPath path) {

		}

		public void onEnd(ElementPath path) {
			Element valueElement = path.getCurrent();
			String strValue = null;
			strValue = valueElement.getText();
			list.add(strValue);
		}
	}

	private class SetHandler implements ElementHandler {
		Map<String, Field> mapField;
		Object obj;
		Attribute nameAttribute;
		Set<String> set;

		public SetHandler(Map<String, Field> mapField, Object obj,
				Attribute nameAttribute) {
			this.mapField = mapField;
			this.obj = obj;
			this.nameAttribute = nameAttribute;
		}

		public void onStart(ElementPath path) {
			set = new HashSet<String>();
			path.addHandler("value", new SetValueHandler(set));
		}

		public void onEnd(ElementPath path) {
			path.removeHandler("value");
			Field tmpField = mapField.get(nameAttribute.getValue());
			if (tmpField != null) {
				tmpField.setAccessible(true);
				setFieldValue(obj, tmpField, set);
			}
		}
	}

	private class SetValueHandler implements ElementHandler {
		Set<String> set;

		public SetValueHandler(Set<String> set) {
			this.set = set;
		}

		public void onStart(ElementPath path) {

		}

		public void onEnd(ElementPath path) {
			Element valueElement = path.getCurrent();
			String strValue = null;
			strValue = valueElement.getText();
			set.add(strValue);
		}
	}

	private class MapHandler implements ElementHandler {
		Map<String, Field> mapField;
		Object obj;
		Attribute nameAttribute;
		Map<String, String> map;

		public MapHandler(Map<String, Field> mapField, Object obj,
				Attribute nameAttribute) {
			this.mapField = mapField;
			this.obj = obj;
			this.nameAttribute = nameAttribute;
		}

		public void onStart(ElementPath path) {
			map = new HashMap<String, String>();
			path.addHandler("entry", new MapEntryHandler(map));
		}

		public void onEnd(ElementPath path) {
			path.removeHandler("entry");
			Field tmpField = mapField.get(nameAttribute.getValue());
			if (tmpField != null) {
				tmpField.setAccessible(true);
				setFieldValue(obj, tmpField, map);
			}
		}
	}

	private class MapEntryHandler implements ElementHandler {
		Map<String, String> map;

		public MapEntryHandler(Map<String, String> map) {
			this.map = map;
		}

		public void onStart(ElementPath path) {
			Element entryElement = path.getCurrent();
			Attribute keyAttribute = entryElement.attribute("key");
			path.addHandler("value", new MapValueHandler(keyAttribute, map));
		}

		public void onEnd(ElementPath path) {
			path.removeHandler("value");
		}
	}

	private class MapValueHandler implements ElementHandler {
		Map<String, String> map;
		Attribute keyAttribute;

		public MapValueHandler(Attribute keyAttribute, Map<String, String> map) {
			this.keyAttribute = keyAttribute;
			this.map = map;
		}

		public void onStart(ElementPath path) {

		}

		public void onEnd(ElementPath path) {
			Element valueElement = path.getCurrent();
			String strValue = null;
			strValue = valueElement.getText();
			map.put(keyAttribute.getText(), strValue);
		}
	}

	private class RefHandler implements ElementHandler {
		Map<String, Field> mapField;
		Object obj;
		Attribute nameAttribute;
		Object bean;

		public RefHandler(Map<String, Field> mapField, Object obj,
				Attribute nameAttribute) {
			this.mapField = mapField;
			this.obj = obj;
			this.nameAttribute = nameAttribute;
		}

		public void onStart(ElementPath path) {
			Element refElement = path.getCurrent();
			Attribute beanAttribute = refElement.attribute("bean");
			bean = beanMap.get(beanAttribute.getText());
		}

		public void onEnd(ElementPath path) {
			Field tmpField = mapField.get(nameAttribute.getValue());
			if (tmpField != null) {
				tmpField.setAccessible(true);
				setFieldValue(obj, tmpField, bean);
			}
		}
	}

	public static void main(String[] args) {
		try {
			BeanFactory factory = new BeanFactory();
			factory.init("setting.xml");

			Person p1 = (Person) factory.getBean("me");
			System.out.print(p1.getName() + " ");
			System.out.print(p1.getAge() + " ");
			System.out.println(p1.getHeight());

			Person p2 = (Person) factory.getBean("you");
			System.out.print(p2.getName() + " ");
			System.out.print(p2.getAge() + " ");
			System.out.println(p2.getHeight());

			ListOne list = (ListOne) factory.getBean("myList");
			System.out.println(list.getMsg());

			SetOne set = (SetOne) factory.getBean("mySet");
			System.out.println(set.getMsg());

			MapOne map = (MapOne) factory.getBean("myMap");
			System.out.println(map.getMsg());

			Persons us = (Persons) factory.getBean("us");
			System.out.println(us.getI());
			System.out.println(us.getU());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}