Comprehensive application of File

 Packagecom.beiwo.homework;ImportJava.io.File;/*4. Look up all the files in a folder and analyze them in a certain format: 1. A file exists in a folder, and subfolders 2. In addition to the current folder, files in subfolders also need to be found.                          3. Sub-file Find files and the current file to find files is the same operation, you can define a method to do file lookup 3. Delete data from a week ago 2. Gets the size of all the files in the folder 1. Determine if there are hidden files */ Public classHomework {Static inttotalsize = 0;//will only be created once        /**     * @paramargs*/     Public Static voidMain (string[] args) {//TODO auto-generated Method Stub//1. Get the specified folderFile File =NewFile ("D:\\java courseware and materials \ \ 18th Class"); //2. Methods for invoking lookupsGetFile (file, 1); //3. Total size of the printed fileSYSTEM.OUT.PRINTLN ("Total size of the folder:" +totalsize*1.0/(1024x768 *1024*1024) + "G"); }        //4. Judging hidden files     Public Static Booleangethiddenfile (file file) {returnFile.ishidden (); }        //3. Get the size of all files in a folder     Public Static voidgetfilesize (file file) {if(File.isfile ()) {totalsize+=file.length (); }             }            //delete a week ago data     Public Static voiddeleteafterweekfile (file file) {//1. Get the last time the file was manipulated        LongLasttime =file.lastmodified (); //2. Get the current time in milliseconds        LongCurrentTime =System.currenttimemillis (); //3. How to do time difference milliseconds        LongTime = CurrentTime-Lasttime; //4. Convert the number of milliseconds to days        intDay = (int) (Time/(1000*60*60*24)); if(day>=7){                        //Delete file Operation            if(File.isfile ()) {file.delete (); }                    }                    }            //Differentiate directory structure     Public StaticString Flag (intcount) {String str="";  for(inti = 0; I < count; i++) {str+="--"+" "; }        returnstr; }        /*** Find all the files in the folder *@paramTargetPath: The path of the file that needs to be found *@paramcount: Record the number of subdirectories*/     Public Static voidGetFile (File file,intCount) {//1//gets the abstract path of the file//File File = new file (TargetPath);                if(File.exists ()) {//represents a folder exists//get files and folders in the current directoryfile[] Files =File.listfiles ();  for(File file2:files) {//Print OutputSYSTEM.OUT.PRINTLN (Flag (count) +file2.getname ()); //Whether the File2 is a folder or a file                if(File2.isdirectory ()) {//File2 is a folder//count++;//count = count+1//Count 2 3//continue to find recursive callsGetFile (file2,count+1);//2 count = 1                                    }                                //determine if the file needs to be deleted                if(File2.isfile ()) {deleteafterweekfile (file2); //Get total File sizeGetFileSize (file2); }                             //to determine if there is hidden data                if(Gethiddenfile (file2)) {System.out.println (File2.getname ()+ "This is a hidden file"); }            }                    }    }}

Comprehensive application of File