Tool class for storing/reading characters in memory or SD card using Io

Filemanager

Package COM. kale. utils; import Java. io. bufferedreader; import Java. io. file; import Java. io. fileinputstream; import Java. io. filenotfoundexception; import Java. io. fileoutputstream; import Java. io. ioexception; import Java. io. inputstream; import Java. io. inputstreamreader; import Java. io. outputstream; import Java. io. printstream; import android. content. context; import android. OS. environment;/*** @ Author: Jack Tony * @ Tips: * <! -- Read and write permissions on the SD card --> <uses-Permission Android: Name = "android. permission. read_external_storage "/> <uses-Permission Android: Name =" android. permission. write_external_storage "/> * @ Date: 2014-6-30 */public class filemanager {private string sd_path; private string filename; private string dirname; Public String getsd_path () {return sd_path ;} /*** @ Param permission: whether the permission is added */Public filemanager (Boolean PE Rmission) {// obtain the directory sd_path = environment of the current external storage device. getexternalstoragedirectory () + "/";}/*** create a file on the SD card ** @ throws ioexception */Public file creatsdfile (string dirname, string filename) throws ioexception {This. filename = filename; this. dirname = dirname; file = new file (creatsddir (dirname), filename); Return file;} Public String getfilewholepath () throws ioexception {If (dirname = NULL | Filename = NULL) {return sd_path + dirname + "/" + filename;} else {Throw new ioexception ("can't find dirname or FILENAME ");}} /*** create a directory on the SD card ** @ Param dirname */Public file creatsddir (string dirname) {file dir = new file (sd_path + dirname); Dir. mkdir (); Return dir;}/*** determines whether the folder on the SD card exists * kale,file.txt-> Kale/file.txt */Public Boolean isfileexist (string dirname, string filename) {f Ile file = new file (sd_path + dirname + "/" + filename); Return file. exists ();}/*** write data in an inputstream to the SD card * example: kale,file.txt, inputstream-> Kale/file.txt * inputstream is = new bytearrayinputstream ("Kale data ". getbytes (); manager. savetosdcard ("dir02", "kale.txt", is); */Public file savetosdcard (string dirname, string filename, inputstream input) {file = NULL; outputstream output = N Ull; try {// create the directory creatsddir (dirname); // create a file = creatsdfile (dirname, filename); Output = new fileoutputstream (File ); byte buffer [] = new byte [5*1024]; // int COUNT = 0; while (input. read (buffer ))! =-1) {// string STR = new string (buffer, 0, count); // STR = new string (Str. getbytes ("iso-8859-1"), "UTF-8");/* system. out. println ("--------- File Manager ---- start --------"); system. out. println (STR); system. out. println ("--------- File Manager ----- end -------"); */output. write (buffer);} output. flush ();} catch (exception e) {e. printstacktrace ();} finally {try {output. close ();} catch (exception e) {e. print Stacktrace () ;}} return file ;}/ *** @ Param dirname * @ Param filename * @ return refers to the characters that read files from the SD card, returns string * @ throws exception */Public String readfromsdcard (string dirname, string filename) throws filenotfoundexception {try {file = new file (sd_path + dirname + "/" + filename ); fileinputstream FCM = new fileinputstream (File); bufferedreader BR = new bufferedreader (New inputstreamreader (ISI); stri Ngbuilder sb = new stringbuilder (""); string line = NULL; // read the file content cyclically while (line = Br. Readline ())! = NULL) {sb. append (line);} BR. close (); return sb. tostring (). trim ();} catch (filenotfoundexception e) {e. printstacktrace (); throw new filenotfoundexception ("No such file");} catch (exception e) {e. printstacktrace ();} return NULL ;} ////////////////////// directly read the files in the package name folder, instead of writing the string to data/ * example: write(file.txt, data) */public static void write (context mcontext, string filename, string Str) {try {/*** mode_private: the file can only be read and written by the current program mode_append: open the file in append mode. The newly written content is appended to the end * mode_world_readable: The file content can be read by other programs * mode_world_writeable: the file content can be read and written by other programs */fileoutputstream Fos = mcontext. openfileoutput (filename, context. mode_private | context. mode_append); printstream PS = new printstream (FOS); // output file content ps. println (STR); PS. close ();} catch (exception e) {e. printstacktrace () ;}}/*** use the file name to read the file * example: Read ("file.txt") under data/package name/Files ") * @ return * returns NULL, indicating that the file cannot be found or an exception */public static string read (context mcontext, string filename) {try {// open the file input stream fileinputstream FCM = mcontext. openfileinput (filename); byte [] buff = new byte [1024]; int hasread = 0; stringbuilder sb = new stringbuilder (""); // read the object content while (hasread = Fi. read (buff)> 0) {sb. append (new string (buff, 0, hasread);} // close the input stream of the file. close (); return sb. tostring ();} catch (filenotfoundexception e) {e. printstacktrace ();} catch (exception e) {e. printstacktrace ();} return NULL ;}}

 

Tool class for storing/reading characters in memory or SD card using Io