定义了一个类，saveToRom函数将指定的数据写入tel.txt文件，loadFromRom从tel.txt文件读取数据

import android.content.Context;     import java.io.FileInputStream;  import java.io.FileOutputStream;     /**   * Created by test on 2014/9/12.   */  public class SaveDataService {         //定义应用程序的上下文      private Context context;         //构造函数      public SaveDataService(Context context){          this.setContext(context);      }         private void setContext(Context context){          this.context = context;      }         /*      写入文件到rom       */      public void saveToRom(String tel,String content){          try {              FileOutputStream fos =  context.openFileOutput("tel.txt", Context.MODE_PRIVATE);              String data = tel +":" + content;              fos.write(data.getBytes());              fos.flush();              fos.close();          }          catch(Exception e)          {              e.printStackTrace();          }      }         public String loadFromRom(){          String result = "";          try {              StringBuffer sb = new StringBuffer();              FileInputStream fis =  context.openFileInput("tel.txt");              int ch;              while((ch=fis.read()) !=-1) {                  sb.append((char)ch);              }              fis.close();              result = sb.toString();          }          catch(Exception e)          {              e.printStackTrace();          }          return result;      }  }