安卓通過檔案存儲資料

話不多說直接上工具類：

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.LinkedHashMap;

import android.content.Context;

public class SaveTheDataUtil {

	/**
	 * 讀取hashmap類型的資料
	 * @param activity
	 * @param fileName
	 * @return
	 */
	public static Object readData(Context activity, String fileName) {
		try {
			String path = activity.getCacheDir().getAbsolutePath() + fileName;
			FileInputStream fis = new FileInputStream(path);
			ObjectInputStream ois = new ObjectInputStream(fis);
			Object list = ois.readObject();
			ois.close();
			fis.close();
			return list;
		} catch (Exception e) {
			Functions.printStackTrace(e);
		}
		return null;
	}

	/**
	 * 儲存hashmap類型的資料
	 * @param activity
	 * @param fileName
	 * @param linkedHashMap
	 */
	public static void saveData(Context activity, String fileName,
			LinkedHashMap<?, ?> linkedHashMap) {
		FileOutputStream fs;
		try {
			String path = activity.getCacheDir().getAbsolutePath() + fileName;
			File file = new File(path);
			if (!file.exists()) {
				file.createNewFile();
			}
			fs = new FileOutputStream(path);
			ObjectOutputStream os = new ObjectOutputStream(fs);
			os.writeObject(linkedHashMap);
			os.close();
			fs.close();
		} catch (Exception e) {
			Functions.printStackTrace(e);
		}
	}

	/**
	 * 清空已有的檔案内容，以便下次重新寫入新的内容
	 * @param fileName
	 */
	public static void clearInfoForFile(String fileName) {
		File file =new File(fileName);
		try {
			if(!file.exists()) {
				file.createNewFile();
			}
			FileWriter fileWriter =new FileWriter(file);
			fileWriter.write("");
			fileWriter.flush();
			fileWriter.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 在已有的檔案後面追加資訊
	 * @param fileName
	 * @param info
	 */
	public static void appendInfoToFile(String fileName, String info) {
		File file =new File(fileName);
		try {
			if(!file.exists()){
				file.createNewFile();
			}
			FileWriter fileWriter =new FileWriter(file, true);
			info = info +System.getProperty("line.separator");
			fileWriter.write(info);
			fileWriter.flush();
			fileWriter.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * readLine方法來逐行文本内容
	 * @param fileName
	 * @return
	 */
	public static String readInfoFromFile(String fileName) {
		File file =new File(fileName);
		if(!file.exists()) {
			return null;
		}
		String resultStr = "";
		try {
			BufferedReader bufferedReader =new BufferedReader(new FileReader(file));
			String str = null;
			StringBuilder sb = new StringBuilder();
			while(null !=(str=bufferedReader.readLine())) {
				sb.append(str+System.getProperty("line.separator"));
			}
			bufferedReader.close();
			resultStr = sb.toString();
		}catch (IOException e) {
			e.printStackTrace();
		}
		return resultStr;
	}
}