完整的java文件读写工具类

package com.dxm.util; /*------------------------------------------------------------------------ 在此类执行操作前请确保获得权限 <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission> ------------------------------------------------------------------------ */ import android.os.Environment; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.BufferedReader; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.net.HttpURLConnection; import java.net.URL; public class TIo{ //SD卡要目录 public static String SDPATH = Environment.getExternalStorageDirectory().getPath() + "/"; //返回文件或目录全名 public static String getFullPath( String AFileOrDir) { return SDPATH+AFileOrDir; } //返回目录下的所有子目录或文件对象 public static File[] getFileOrDirList( String ADir) { File[] ARes = null; try { File AFile = new File(SDPATH+ADir); ARes = AFile.listFiles(); } catch(Exception er){ARes = new File[0];} return ARes; } //返回目录下的所有子目录或文件对象名称 public static String[] getFileOrDirNameList( String ADir) { String[] ARes = new String[0]; File[] AFs = getFileOrDirList(ADir); ARes = new String[AFs.length]; for( int i=0;i<AFs.length;i++) { try { ARes[i] = AFs[i].getName(); } catch(Exception er){;} } return ARes; } //创建目录 public static void DoCreateDir( String ADir) { File ADscDir = new File(SDPATH+ADir.replace(SDPATH, "")); if ( !ADscDir.exists()) { String AParentDirName = ADscDir.getParent(); File AParentDir = new File(AParentDirName); if (!AParentDir.exists()) { DoCreateDir(AParentDirName ); } try { ADscDir.mkdir(); } catch(Exception er){ String Error = er.getMessage(); String AE = Error; } } } //返回文件目录名称 public static String getFilePath( String AFileName) { String ARes = ""; try{ int AEndPos = AFileName.lastIndexOf("/"); if ( AEndPos>0) { ARes = AFileName.substring(0, AEndPos ); } } catch(Exception er){;} return ARes; } //写文件 public static Boolean DoWriteTextFile( String AFileName, String AText) { Boolean ARes = false; try { String APathStr= getFilePath( AFileName); File APath = new File(SDPATH+ APathStr); if (!APath.exists()) { DoCreateDir(APathStr); } if ( APath.exists()) { try{ String AFullFileName = SDPATH+ AFileName; File AFile = new File( AFullFileName); AFile.createNewFile(); FileOutputStream fout = new FileOutputStream(AFullFileName ); byte [] bytes = AText.getBytes(); fout.write(bytes); fout.close(); ARes = true; } catch(Exception e){ String Error = e.getMessage(); String AE = Error; } } } catch(Exception er){;} return ARes; } //读文件 public static String DoReadTextFile( String AFileName ) { String ARes = ""; try { String AFullFileName=SDPATH+ AFileName; File AFile = new File( AFullFileName); if (AFile.exists()) { try { FileInputStream fis=new FileInputStream(AFile);//新建一个FileInputStream对象 try { byte[] b=new byte[fis.available()];//新建一个字节数组 fis.read(b);//将文件中的内容读取到字节数组中 fis.close(); String str2=new String(b);//再将字节数组中的内容转化成字符串情势输出 ARes = str2; } catch (IOException e) {;} } catch(Exception er) {;} } } catch(Exception er){;} return ARes; } //从URL下载文本 public static String getUrlText( String AUrl ) { String ARes = ""; try { URL url=new URL(AUrl); HttpURLConnection conn=(HttpURLConnection)url.openConnection(); //取得inputStream，并进行读取 InputStream input=conn.getInputStream(); BufferedReader in=new BufferedReader(new InputStreamReader(input)); String line=null; StringBuffer sb=new StringBuffer(); while((line=in.readLine())!=null){ sb.append(line); } ARes = sb.toString(); } catch(Exception er){;} return ARes; } //下载URL到文件 public static Boolean DoDownload(String AUrl,String AFileName) { Boolean ARes = false; try { String ATxt = getUrlText(AUrl); ARes = DoWriteTextFile(AFileName, ATxt); } catch(Exception er){;} return ARes; } public static InputStream StringTOInputStream(String in) { ByteArrayInputStream is=null; try { is = new ByteArrayInputStream(in.getBytes("UTF-8")); } catch(Exception er){;} return is; } /** * 删除一个文件 * * @param file * @return */ public static boolean DoDelFile(File file) { if (file.isDirectory()) return false; else return file.delete(); } /** * 删除一个文件 * * @param file * @return */ public static boolean DoDelFile(String AFileName) { boolean ARes = false; try { File Af = new File( SDPATH+ AFileName); if ( Af.isFile()) { if ( Af.exists()) { ARes = Af.delete(); } } } catch(Exception er){ ; } return ARes; } public static String InputStreamTOString(InputStream in ) { String Ares =""; try { ByteArrayOutputStream outStream = new ByteArrayOutputStream(); int BUFFER_SIZE = 4096; byte[] data = new byte[BUFFER_SIZE]; int count = -1; while((count = in.read(data,0,BUFFER_SIZE)) != -1) outStream.write(data, 0, count); data = null; Ares = new String(outStream.toByteArray(),"UTF-8"); } catch(Exception er){;} return Ares; } }