Java中回调函数编写

package XXX.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

import org.xmlpull.v1.XmlSerializer;

import android.app.ProgressDialog;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.util.Xml;
import android.widget.ProgressBar;

/**
 * 短信的工具类
 * 
 */
public class SmsUtils {

	/**
	 * 备份短信的回调接口
	 */
	public interface BackUpCallBack {
		/**
		 * 开始备份的时候，设置进度的最大值
		 * 
		 * @param max
		 *            总进度
		 */
		public void beforeBackup(int max);

		/**
		 * 备份过程中，增加进度
		 * 
		 * @param progress
		 *            当前进度
		 */
		public void onSmsBackup(int progress);

	}

	/**
	 * 备份用户的短信
	 * 
	 * @param context
	 *            上下文
	 * @param BackUpCallBack
	 *            备份短信的接口
	 */
	public static void backupSms(Context context, BackUpCallBack callBack)
			throws Exception {
		ContentResolver resolver = context.getContentResolver();
		File file = new File(Environment.getExternalStorageDirectory(),
				"backup.xml");
		FileOutputStream fos = new FileOutputStream(file);
		// 把用户的短信一条一条读出来，按照一定的格式写到文件里
		XmlSerializer serializer = Xml.newSerializer();// 获取xml文件的生成器（序列化器）
		// 初始化生成器
		serializer.setOutput(fos, "utf-8");
		serializer.startDocument("utf-8", true);
		serializer.startTag(null, "smss");
		Uri uri = Uri.parse("content://sms/");
		Cursor cursor = resolver.query(uri, new String[] { "body", "address",
				"type", "date" }, null, null, null);
		// 开始备份的时候，设置进度条的最大值
		int max = cursor.getCount();
		// pb.setMax(max);
		// pd.setMax(max);
		callBack.beforeBackup(max);
		serializer.attribute(null, "max", max + "");
		int process = 0;
		while (cursor.moveToNext()) {
			Thread.sleep(500);
			String body = cursor.getString(0);
			String address = cursor.getString(1);
			String type = cursor.getString(2);
			String date = cursor.getString(3);
			serializer.startTag(null, "sms");

			serializer.startTag(null, "body");
			serializer.text(body);
			serializer.endTag(null, "body");

			serializer.startTag(null, "address");
			serializer.text(address);
			serializer.endTag(null, "address");

			serializer.startTag(null, "type");
			serializer.text(type);
			serializer.endTag(null, "type");

			serializer.startTag(null, "date");
			serializer.text(date);
			serializer.endTag(null, "date");

			serializer.endTag(null, "sms");
			// 备份过程中，增加进度
			process++;
			// pb.setProgress(process);
			// pd.setProgress(process);
			callBack.onSmsBackup(process);
		}
		cursor.close();
		serializer.endTag(null, "smss");
		serializer.endDocument();
		fos.close();
	}

	/**
	 * 还原短信
	 * 
	 * @param context
	 * @param flag
	 *            是否清理原来的短信
	 */
	public static void restoreSms(Context context, boolean flag) {
		Uri uri = Uri.parse("content://sms/");
		if (flag) {
			context.getContentResolver().delete(uri, null, null);
		}
		// 1.读取sd卡上的xml文件
		// Xml.newPullParser();

		// 2.读取max

		// 3.读取每一条短信信息，body date type address

		// 4.把短信插入到系统短息应用。

		ContentValues values = new ContentValues();
		values.put("body", "woshi duanxin de neirong");
		values.put("date", "1395045035573");
		values.put("type", "1");
		values.put("address", "5558");
		context.getContentResolver().insert(uri, values);
	}
}

调用方式：

try {
					SmsUtils.backupSms(getApplicationContext(), new BackUpCallBack() {
						@Override
						public void onSmsBackup(int progress) {
							pd.setProgress(progress);
						}
						@Override
						public void beforeBackup(int max) {
							pd.setMax(max);
						}
					});
					runOnUiThread(new Runnable() {
						@Override
						public void run() {
							Toast.makeText(AtoolsActivity.this, "备份成功", 0).show();
						}
					});
				} catch (Exception e) {
					e.printStackTrace();
					runOnUiThread(new Runnable() {
						@Override
						public void run() {
							Toast.makeText(AtoolsActivity.this, "备份失败", 0).show();
						}
					});
				}finally{
					pd.dismiss();
				}