android java 资料的读写（转）_Android

android java 文件的读写（转）

package?xiaohang.zhimeng;??
??
import?java.io.FileInputStream;??
import?java.io.FileOutputStream;??
import?org.apache.http.util.EncodingUtils;??
import?android.app.Activity;??
import?android.graphics.Color;??
import?android.os.Bundle;??
import?android.widget.TextView;??
??
public?class?Activity01?extends?Activity{??
????//常量，为编码格式??
????public?static?final?String?ENCODING?=?"UTF-8";??
????//定义文件的名称??
????String?fileName?=?"test.txt";??
????//写入和读出的数据信息??
????String?message?=?"欢迎大家来我们群里讨论问题";??
????TextView?textView;??
?????@Override??
????protected?void?onCreate(Bundle?savedInstanceState)?{??
????????super.onCreate(savedInstanceState);??
????????setContentView(R.layout.main);??
????????writeFileData(fileName,?message);??
????????String?result?=?readFileData(fileName);??
????????textView?=?(TextView)findViewById(R.id.tv);??
????????textView.setTextColor(Color.GREEN);??
????????textView.setTextSize(20.0f);??
????????textView.setText(result);??
??????????
????}??
?????//向指定的文件中写入指定的数据??
?????public?void?writeFileData(String?filename,?String?message){??
?????????try?{??
????????????FileOutputStream?fout?=?openFileOutput(filename,?MODE_PRIVATE);//获得FileOutputStream??
????????????//将要写入的字符串转换为byte数组??
????????????byte[]??bytes?=?message.getBytes();??
????????????fout.write(bytes);//将byte数组写入文件??
????????????fout.close();//关闭文件输出流??
????????}?catch?(Exception?e)?{??
????????????e.printStackTrace();??
????????}??
?????}??
???????
?????//打开指定文件，读取其数据，返回字符串对象??
?????public?String?readFileData(String?fileName){??
?????????String?result="";??
?????????try?{??
????????????FileInputStream?fin?=?openFileInput(fileName);??
????????????//获取文件长度??
????????????int?lenght?=?fin.available();??
????????????byte[]?buffer?=?new?byte[lenght];??
????????????fin.read(buffer);??
????????????//将byte数组转换成指定格式的字符串??
????????????result?=?EncodingUtils.getString(buffer,?ENCODING);??
????????}?catch?(Exception?e)?{??
????????????e.printStackTrace();??
????????}??
????????return?result;??
?????}??
} ?