listview顯示歷史數據

listview聯網之前就顯示以前的數據

以前因爲是把數據保存到數據庫，但那樣很麻煩，後來看了oschina客戶端發現把數據序列換然後保存到文件就可以了


import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
 
import android.content.Context;
 
/**
*
* @author zhulei
*
*/
public class FileObj {
    private Context context;
    public FileObj(Context context) {
        this.context = context;
    }
 
    /**
     * 保存對象
     * @param ser
     * @param file
     * @throws IOException
     */
    public boolean saveObject(Serializable ser, String file) {
        FileOutputStream fos = null;
        ObjectOutputStream oos = null;
        try{
            fos = context.openFileOutput(file, Context.MODE_PRIVATE);
            oos = new ObjectOutputStream(fos);
            oos.writeObject(ser);
            oos.flush();
            return true;
        }catch(Exception e){
            e.printStackTrace();
            return false;
        }finally{
            try {
                oos.close();
            } catch (Exception e) {}
            try {
                fos.close();
            } catch (Exception e) {}
        }
    }
 
    /**
     * 讀取對象
     * @param file
     * @return
     * @throws IOException
     */
    public Serializable readObject(String file){
        FileInputStream fis = null;
        ObjectInputStream ois = null;
        try{
            fis = context.openFileInput(file);
            ois = new ObjectInputStream(fis);
            return (Serializable)ois.readObject();
        }catch(FileNotFoundException e){
        }catch(Exception e){
            e.printStackTrace();
 
        }finally{
            try {
                ois.close();
            } catch (Exception e) {}
            try {
                fis.close();
            } catch (Exception e) {}
        }
        return null;
    }
}