MU Lesson Network _ File Transfer base--java IO stream

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1th. Encoding of the document

1-1 encoding of the file (15:07)

2nd. Use of the File class

2-1 File Class Common API introduction (10:50)

Import Java.io.file;import Java.io.ioexception;public class Filedemo {public static void main (string[] args) {File File = New File ("E:\\helloworld\\java"); System.out.println (File.exists ());//Determine if the file/folder exists if (!file.exists ()) {file.mkdirs ();//Create Directory} else {file.delete ();} is a directory System.out.println (File.isdirectory ());//is a file System.out.println (File.isfile ()); File File2 = new file ("E:\\helloworld\\1.txt"), if (File2.exists ()) {try {file2.createnewfile ();//Create Files} catch ( IOException e) {//TODO auto-generated catch Blocke.printstacktrace ();}} else {file2.delete ();} System.out.println (file);//file.tostring () content System.out.println (File.getabsolutepath ()); System.out.println (File.getname ()); System.out.println (File.getparent ());}}

2-2 traversing the directory (10:26)

Import Java.io.file;import java.io.ioexception;//lists some common actions for file such as filtering, traversing, and so on. Class FILEUTILS1 {/* * Lists all files under the established directory (including their subdirectories) * /public static void ListDirectory (File dir) throws IOException {if (!dir.exists ()) {throw new IllegalArgumentException ("Mesh "+ dir +" does not exist ");} if (!dir.isdirectory ()) {throw new IllegalArgumentException (dir + "not Directory");} string[] filenames = dir.list ();//Returns the name of the immediate child of the string array, not including the contents under subdirectories for (string string:filenames) {System.out.println (dir + "\ \ "+ string);}}} Class FILEUTILS2 {/* * Lists all files under the established directory (including its subdirectories) */public static void ListDirectory (file dir) throws IOException {if (!dir.exis TS ()) {throw new IllegalArgumentException ("directory:" + dir + "does not exist");} if (!dir.isdirectory ()) {throw new IllegalArgumentException (dir + "not Directory");} If you want to iterate through the contents of the subdirectory, you need to construct the file object to do the recursive operation, file provides a direct return to the file object apifile[] files = dir.listfiles ();//Returns a direct subdirectory (file) of the object if (Files! = Null && files.length > 0) {for (file file:files) {if (File.isdirectory ()) {listdirectory (file);} else {System . out.println (file);}}}} PubliC class Fileutiltest {public static void main (string[] args) throws IOException {fileutils2.listdirectory (New File ("e:\\k MS "));}}

Chapter 3rd use of Randomaccessfile class

3-1 Randomaccessfile Basic operation (17:16)

Import Java.io.file;import java.io.ioexception;import java.io.randomaccessfile;import java.util.Arrays;/* * The Java.io.File class is used to represent files (directories) * The file class is used only to represent the file (directory) information (name, size, etc.) and cannot be used for access to the contents of the file * * Randomaccessfile Java provides access to the contents of the file, both read and write files. * Randomaccessfile supports random access to files and can access any location of the file. * * (1) Java file model * file on hard disk is a byte byte stored, is a collection of data * * (2) Open file * There are two modes "RW" (Read and write) "R" (read-only) * Randomaccessfile raf=new Randoma Ccessfile (file, "RW"); * file pointer, open file when pointer at the beginning pointer=0; * * (3) write the file * raf.write (int); write only one byte (the last 8 bits), and the pointer points to the next position, ready to write again * * (4) Read the file * int b=raf.read (); Read a byte * * (5) file read and write must be closed after completion (Ora CLE official description) */public class Rafdemo {public static void main (string[] args) throws IOException {file demo = new File ("demo"); F (!demo.exists ()) {demo.mkdirs ();} File File = new file (demo, "Raf.dat"), if (!file.exists ()) {file.createnewfile ();} Randomaccessfile RAF = new Randomaccessfile (file, "RW");//Pointer position System.out.println (Raf.getfilepointer ()); Raf.write (' A ');//write only one byte of System.out.println (Raf.getfilepointer ()); Raf.write (' B '); int i = 0X7FFFFfff;//Write method can be written only one byte at a time, if you want to write I will have to write 4 times raf.write (i >>> 24);//high 8-bit raf.write (i >>>); Raf.write (i >>> 8); Raf.write (i); System.out.println (Raf.getfilepointer ());//You can write a intraf.writeint (i) directly; String s = "medium"; byte[] GBK = s.getbytes ("GBK"); Raf.write (GBK); System.out.println (Raf.length ());//Read the file, you must move the pointer to the head raf.seek (0);//One-time read, read the contents of the file into a byte array byte[] buf = new byte[(int) Raf.length ()];raf.read (BUF); System.out.println (arrays.tostring (BUF)); string S1 = new String (buf, "GBK"); System.out.println (S1); for (byte b:buf) {System.out.println (integer.tohexstring (b & 0xff) + "");} Raf.close ();}}

Chapter 4th Byte Stream

4-1-byte stream file input stream FileInputStream-1 (15:09)

4-2-byte stream file input stream FileInputStream-2 (08:40)

4-3-byte stream file output stream FileOutputStream (13:24)

Data input and output stream of 4-4-byte stream (11:08)

4-5-byte buffered stream (17:54)

5th Chapter Character Stream

5-1-byte character conversion stream (18:09)

5-2 character stream file read and write streams (05:56)

Filter for 5-3 character streams (10:25)

The 6th chapter, serialization and deserialization of objects

6-1 serialization of basic operations (10:30)

6-2 Transient and ArrayList source analysis (12:41)

6-3 serialization of a neutron parent constructor problem (11:43)

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MU Lesson Network _ File Transfer base--java IO stream