java--Print Flow, Commons-io

One, the print flow

1. Overview of the print flow

The print stream adds the ability to output data so that they can easily print various data value representations .

The print flow is categorized according to the flow:

(1) byte print stream PrintStream

(2) character print stream PrintWriter

Method:

void print (String str): Outputs any type of data,

void println(String str): Outputs any type of data, automatically writes a line-break operation

2. Code Demo:

1 //How does the print stream output2      Public Static voidMETHOD5 ()throwsioexception{3         //Clear Data Purpose4FileOutputStream fos=NewFileOutputStream ("E:\\test\\test.txt");5PrintStream ps=NewPrintStream (FOS);6Ps.print ("Zhang San");7Ps.println ("Hello");8Ps.println (true);9         //Freeing ResourcesTen ps.close (); One     } A     //Print stream Copy file -      Public Static voidMethod6 ()throwsioexception{ -         //Clear Data Source theFileReader fr=NewFileReader ("E:\\test\\test.txt"); -BufferedReader br=NewBufferedReader (FR); -         //Clear Data Purpose -FileWriter fw=NewFileWriter ("E:\\test\\pig.txt"); +PrintWriter pw=NewPrintWriter (FW,true);//Auto Refresh -         //Copy +String line=NULL; A          while((Line=br.readline ())! =NULL){ atPw.println (line);//Refresh + line break -         } -         //Freeing Resources - br.close (); - pw.close (); -}

Second, Commons-io1. Guide Package

class files in third-party jar packages that are added to Classpath can be used in projects

Create lib folder

Copy the Commons-io.jar to the lib folder

Right click on commons-io.jar,build path→Add to build path

2.FilenameUtils

This tool class is used to deal with file name (Translator Note: include file path), he can easily solve different operating system file names specification of different issues

Common methods:

GetExtension (String path): Gets the file name extension;

GetName (): Gets the file name;

Isextension (String filename,string ext): Determine If filename is the ext suffix name;

Code implementation:

1  Public Static voidMethod7 () {2         //get a file name extension3String name=filenameutils.getextension ("E:\\test");4 System.out.println (name);5         //get a file name6String filename=filenameutils.getname ("E:\\test\\test.txt");7 System.out.println (filename);8         //determine whether a file ends with what9         BooleanFlag=filenameutils.isextension ("Aaa.java", "Java");Ten System.out.println (flag); One}

3.FileUtils

Provides methods for file operations (moving files, reading files, checking whether files exist, and so on).

Common methods:

Readfiletostring (File file): reads the contents of the files and returns a string;

Writestringtofile (file file,string content): writes contents to file;

Copydirectorytodirectory (File srcdir,file destDir), folder replication

CopyFile (file Srcfile,file destfile);

Code implementation:

1 //Fileutils class2      Public Static voidMethod8 ()throwsioexception{3         //Copy Folder4Fileutils.copydirectory (NewFile ("E:\\test"),NewFile ("E:\\test2"));5         //Copying Files6Fileutils.copyfile (NewFile ("E:\\test\\test.txt"),NewFile ("E:\\test\\test5.txt"));7}

java--Print Flow, Commons-io