Create folder path and new file for Java file operations

One: The problem

(1) Java If the folder path does not exist, create first;

(2) If the file name does not exist, first create the re-read and write, if there is a direct append, keyword True

(3)file MyPath = new file (Tofilepath);
if (!mypath.exists ()) {//If this directory does not exist, then create it//this thing can only resume level folder, level Two is not built .....
Mypath.mkdir ();
System.out.println ("Create Folder path:" + Tofilepath);
}
The code above can only create a first level directory, can not create a level two directory, that is, only the current level of the directory can be created, if the previous level of the directory does not exist, the creation fails; Of course, you can solve this problem by recursive creation.

File MyPath = new file (Tofilepath); Just pass the path to the private property of the File.java class, see the source code, and do not open the file, so do not throw FileNotFoundException

(4) //write file name processing

String filen = tofilepath + "\ \" + FileName;
bufferedwriter writer = new BufferedWriter (new FileWriter (New File (Filen)));

Compare with the following code

File File=new file (OriginalPath);
if (File.isfile () && file.exists ()) {//Determine if the file exists
InputStreamReader Read = new InputStreamReader (
New FileInputStream (file), encoding);//considering the encoding format
BufferedReader bufferedreader = new BufferedReader (read);

}

In fact, FileWriter is packaged (called) the FileOutputStream () function source code is as follows: So the two are similar, but the stream can filter the code.

Public FileWriter (file file) throws IOException {
Super (new FileOutputStream (file));
}

Two: Code implementation

[Java]View PlainCopyPrint?

2. Package  Edu.tju.cs;
6. Import  Java.io.File;
8. Import  java.io.FileNotFoundException;
10. Import  Java.io.FileWriter;
12. Import  java.io.IOException;
14. Import  Java.io.RandomAccessFile;
20. Public class alltest {
24. /*public static void Main (string[] args) {
26. System.out.println ("****\\\\");
28. String str = "A\\B\\B\\C.CSV|AAAAA";
30. string[] chars = Str.split ("\\\\");
32. string[] FileName = chars[3].split ("\ \"); /u002e
34. string[] tmp = Chars[3].split ("\\u007c");//\\u007c
36. For (String cha:chars) {
38. System.out.println (cha);
40.         }
42. System.out.println (filename[0]);
44. System.out.println (tmp[1]);
46.     }*/  
50. Public static void main (String args[])
52. {
54. StringBuffer filebuf=New stringbuffer ();
56. String Filepar = "D:\\test"; //Folder path   
58. File MyPath = new file (filepar);
60. if (!mypath.exists ()) {//If this directory does not exist, the created
62. Mypath.mkdir ();
64. System.out.println ("Create folder path:"+ filepar);
66. }
68. //folder path exists in case   
70. String filename = "test.txt"; //File name   
72. Try  {  
74. FileWriter FW = new FileWriter (filepar + "\" + filename,true);//Filepar + "\ \" + filename ,true
76. //FileWriter is a cow, if the file name does not exist, first create re-read and write;   
78. String originalline = "Aaaaaaaaaa" + "\ n"; //    
80. SYSTEM.OUT.PRINTLN ("* * *"+ originalline);
82. Fw.write (Originalline);
84. //Close Write file, write only one line of data at a time, because a read file is only a single OD   
86. Fw.close ();
88. } catch (IOException e) {
90. //TODO auto-generated catch block   
92. E.printstacktrace ();
94. }
96. }
98. }

Package Edu.tju.cs;import Java.io.file;import Java.io.filenotfoundexception;import java.io.filewriter;import Java.io.ioexception;import Java.io.randomaccessfile;public class AllTest {/*public static void main (string[] args)        {System.out.println ("****\\\\");        String str = "A\\B\\B\\C.CSV|AAAAA";        string[] chars = Str.split ("\\\\"); string[] FileName = chars[3].split ("\ \"); /u002e string[] tmp = Chars[3].split ("\\u007c");//\\u007c for (String cha:chars) {SYSTEM.OUT.PR        Intln (CHA);        } System.out.println (Filename[0]);    System.out.println (tmp[1]);            }*/public static void Main (String args[]) {stringbuffer filebuf=new stringbuffer ();            String Filepar = "d:\\test";//folder path File MyPath = new file (Filepar);                if (!mypath.exists ()) {//If this directory does not exist, then create the Mypath.mkdir ();            System.out.println ("Create Folder path:" + Filepar); }//FolderThe path exists in the case of String filename = "test.txt";//File name try {FileWriter fw = new FileWriter (fil EPar + "\" + filename,true),//Filepar + "\ \" + filename,true//FileWriter is the cow, if the file name does not exist, first create and read and write; Append write, the keyword true means append String originalline = "aaaaaaaaaa" + "\ n";//System.out.println ("* * *" + ori                Ginalline);                Fw.write (Originalline);            Closes the write file, writes only one line of data at a time, because a read file is only a single od fw.close ();            } catch (IOException e) {//TODO auto-generated catch block E.printstacktrace (); }      }}

AnywayFileWriter is a cow, if the file name does not exist, first create re-read and write, if there is a direct append write, the keyword true means append but he can only one line of read and write, rather than the generation of buffer read and write efficiency high

Java a variety of ways to read files, append file content, to file the various operations see: Java a variety of ways to read files, append file content, various operations on the file

Create folder path and new file for Java file operations