Android 使用全局变量

package cn.com.smartcost.cld.entity;

import android.app.Application;

/**
 * APP的全局变量
 * @author wangfeng
 * @date 2013-12-18 15:23:34
 */
public class AppData extends Application {
	private User user;

	public User getUser() {
		return user;
	}

	public void setUser(User user) {
		this.user = user;
	}
	

	
	
	
}

<application
        android:allowBackup="true"
        android:icon="@drawable/icon"
        android:label="@string/app_name"
         android:name="cn.com.smartcost.cld.entity.AppData"
        android:theme="@style/AppTheme" >

appData = (AppData)getApplication();

appData.setUser(user);

appData = (AppData)getApplication();

appData.getUser();