文件读写操作汇总解析

来源：互联网发布：linux漏洞列表编辑：程序博客网时间：2024/05/22 05:10

转载博客：http://www.cnblogs.com/lianghui66/archive/2013/09/05/3303546.html

InputStream 字节流输入类，读取byte数组

Reader 字符流读取类，读取Char数组和String对象

FileInputStream 文件输入字节流

BufferedReader 带缓冲的字符流读取

InputStreamReader jiang字节流转换为字符流的一个类，构造方法的参数是字节输入流

FileReader 继承InputStreamReader类，构造方法的参数是文件对象或者文件路径名称

用FileInputStream(FileOutputStream)读写文件

public void write(String fileName,StringwriteString) throws Exception{try{         FileOutputStreamfout=openFileOutput(fileName,MODE_PRIVATE);         byte[]bytes=writeString.getBytes();         fout.write(bytes);         fout.close();   }catch(Exception e){         e.printStackTrace();   }} public String read(String fileName){String res=””;try{         FileInputStreamfin=openFileInput(fileName,MODE_PRIVATE);         intlength=fin.available();         byte[]buffer=new byte[length];         fin.read(buffer);         res=EncodingUtils.getString(buffer,”UTF-8”);         fin.close();   }catch(Exception e){       e.printStackTrace();   }return res;}

用BufferedReader和FileReader读文件

import java.io.BufferedReader;import java.io.FileReader;import java.io.IOException;import java.io.File;import android.util.Log;private String getCoulometerValue(String batterypath){String procElectricityStr;try{BufferedReader reader=new BufferedReader(new FileReader(batterypath),256);try{procElectricityStr=reader.readLine();                   }finally{               reader.close();                   }        return procElectricityStr;          }catch(IOException e){    e.printStackTrace();    return “Unavailable”;           }}

用BufferedReader,InputStreamReader,FileInputStream（BufferedWriter,OutputStreamWriter,FileOutputStream）读写文件

public String load(String fileName){FileInputStream in=null;BufferedReader reader=null;StringBuilder content=new StringBulider();try{in=openFileInput(fileName);reader=new BufferedReader(new InputStreamReader(in));String line=””;while((line=reader.readLine())!=null){content.append(line);                }           }catch(IOException e){       e.printStackTrace()           }finally{   if(reader!=null)     try{reader.close()                }catch(IOException e){            e.printStackTrace();                 }                }               }                 return content.toString();}

public void Save(String fileName,String data){FileOutputStream out=null;BufferedWriter writer=null;try{out=openFileOutput(fileName,Context.MODE_PRIVATE);writer=new BufferedWriter(new OutputStreamWriter(out));writer.write(data);           }catch(IOException e){              e.printStackTrace();           }finally{             if(writer!=null){        writer.close();           }catch(IOException){      e.printStackTrace();           }        }}

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