學(xué)習(xí)了What is IAdaptable？這篇文章，有點(diǎn)困惑，干脆做個(gè)demo鞏固下，包括三個(gè)部分：OldObject 、NewObject和工廠類YearFactory

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.Platform;

// 實(shí)現(xiàn)了IAdaptable 接口
public class OldObject implements IAdaptable {
	private String yearmonthday;

	public String getYearmonthday() {
		return yearmonthday;
	}

	public void setYearmonthday(String yearmonthday) {
		this.yearmonthday = yearmonthday;
	}

	public Object getAdapter(Class adapter) {
		return Platform.getAdapterManager().getAdapter(this, adapter);
	}

}

public class NewObject {
    private String year; 

    public String getYear() {
        return year;
    } 

    public void setYear(String year) {
        this.year = year;
    } 

}

完成具體的轉(zhuǎn)換

import org.eclipse.core.runtime.IAdapterFactory;
public class YearFactory implements IAdapterFactory {
	private static final Class[] types = { NewObject.class };

	public Object getAdapter(Object old, Class clazz) {
		if (clazz == NewObject.class && old instanceof OldObject) {
			NewObject objectNew= new NewObject();
			objectNew.setYear(((OldObject) old).getYearmonthday().substring(2)); //隨意的規(guī)則
			return objectNew;
		} else {
			return null;
		}

	}

	public Class[] getAdapterList() {
		return types;
	}

}

調(diào)用轉(zhuǎn)換的代碼：

Platform.getAdapterManager().registerAdapters(new YearFactory(), OldObject.class);
OldObject old = new OldObject();
old.setYearmonthday("20070914");

Object adaptable = old.getAdapter(NewObject.class);
if (adaptable != null) { 

    NewObject node = (NewObject) adaptable; 

   System.out.println(node.getYear());

 } 

總結(jié)：

術(shù)語(yǔ)：源對(duì)象、轉(zhuǎn)換類型、工廠

目的：實(shí)現(xiàn)兩個(gè)不相關(guān)對(duì)象的轉(zhuǎn)換

（1）源對(duì)象需要實(shí)現(xiàn)IAdaptable接口，或者繼承PlatformObject抽象類

（2）在源對(duì)象IAdaptable接口方法getAdapter的實(shí)現(xiàn)可以如下，即直接轉(zhuǎn)發(fā)給AdapterManager的getAdapter()方法

 public Object getAdapter(Class adapter) {

    return Platform.getAdapterManager().getAdapter(this, adapter);

}

（3）實(shí)現(xiàn)轉(zhuǎn)換工廠類，具體負(fù)責(zé)轉(zhuǎn)換，需要實(shí)現(xiàn)IAdapterFactory接口，其接口方法getAdapterList()負(fù)責(zé)通知AdapterManager轉(zhuǎn)換類型，

而getAdapter方法具體完成轉(zhuǎn)換

（4）將轉(zhuǎn)換工廠類注冊(cè)到AdapterManager：

Platform.getAdapterManager().registerAdapters(new YearFactory(), OldObject.class); 

這樣的好處在于，如果源對(duì)象需要轉(zhuǎn)換到多個(gè)不相關(guān)的對(duì)象的時(shí)候，不需要修改源對(duì)象，而直接轉(zhuǎn)發(fā)給相應(yīng)的工廠類，這樣在一定程度上保護(hù)了源對(duì)象免于修改，

而是修改或者增加新的工廠類。