3 Ways To Re-Create A File From I Directory To Roughly Other Inwards Java

Even though Java is considered 1 of the best feature-rich programming language, until Java 7, It didn't conduct maintain any method to re-create a file from 1 directory to some other directory. It did conduct maintain the java.io.File class, which provides a method to check if a file exists or non too methods for several other file operations but it lacks back upwards for copying file from 1 folder to another. It was slow to write your ain routine to re-create a file using FileInputStream or FileChannel, most developers prefer to usage Apache Commons IO library; which is non a bad view at all. Even Joshua Bloch (author of several Java classes inwards JDK, including Java Collection Framework) advise using libraries instead of reinventing wheels inwards must read Effective Java book. The Apache Commons IO library provides a shape called FileUtils, which contains several file utility methods including 1 for copying file from 1 directory to another.

Btw, Java has addressed the upshot of a simpler, powerful, too characteristic rich file too directory library past times introducing NIO 2.0 inwards JDK. In short, from Java vii onwards, y'all don't take away to include Apache Commons IO simply for copying file, y'all tin instead usage Files.copy(source, destination) method to re-create files from 1 folder to some other inwards Java. This method takes Path of source too finish folder too copies the file (see Core Java Volume ii - Advanced features to acquire to a greater extent than well-nigh other useful files too directories related features added equally component of NIO 2.0)

You tin however usage Apache common IO for whatever missing functionality, but I doubtfulness y'all would take away it post JDK vii novel File IO package. Also if y'all are running on Java five or 6, y'all tin conduct maintain a facial expression at FileChannel because it operates on buffer level, y'all tin usage it to re-create large files from 1 place to some other real efficiently.

3 examples to re-create a file from 1 place to another

In this article, I'll present y'all 3 uncomplicated ways to re-create a file from 1 folder to some other using Java program. These 3 approaches shows how to re-create a file inwards Java half-dozen or lower version past times using key FileInputStream shape without using a third-party library, Apache Commons IO agency for those who similar to usage a third-party library, too endure the criterion agency of copying file post-Java vii using NIO 2.0 classes.

1) Copy file using FileInputStream

This is the simplest solution to re-create a file inwards Java too the best component of this code is that it volition piece of occupation inwards all version of Java, starting from Java 1 to Java 8.  This method expects to source too finish file, which likewise encapsulate the path inwards the file organisation too and thus uses FileInputStream to read from source file too FileOutputStream to write to the finish file using a buffer (byte array) of 1KB.

private static void copy(File src, File dest) throws IOException {         InputStream is = null;         OutputStream os = null;         try {             is = new FileInputStream(src);             os = new FileOutputStream(dest);              // buffer size 1K             byte[] buf = new byte[1024];              int bytesRead;             while ((bytesRead = is.read(buf)) > 0) {                 os.write(buf, 0, bytesRead);             }         } finally {             is.close();             os.close();         }     }

You tin usage this Java code to re-create a file from 1 place to other inwards your projection but I would strongly advise using either Apache Commons IO or Files.copy() if y'all are running inwards Java 7. This event is skillful for learning but y'all take away to a greater extent than characteristic rich method for production use

2) Using Apache Commons IO (Only for Java five too 6)

Even though the previous event of copying file was uncomplicated to code it wasn't view to grip all scenarios too may neglect spell copying large files. This is where tertiary -party library marker good because they acquire the huge testing exposure amongst their large user base of operations roughly the the world too across the domain.

public static void copyFileUsingApache(File from, File to) throws IOException{         FileUtils.copyFile(from, to);     }

Another payoff of using a third-party library similar Apache Commons too Google Guava is that y'all take away to write less code. Here nosotros are simply calling the FileUtils.copyFile() method, nada else. Though, y'all may bring out nosotros conduct maintain encapsulated the telephone telephone to a third-party library inwards our ain method. This is to protect every component of our code from straight subject on this library. Tomorrow if y'all determine to usage Google Guava or switch to Java vii criterion agency of copying, y'all alone take away alter this method too non every component of your code which using this method for copying.

3) Files.copy() from (Java vii onwards)

This is the best too correct agency to re-create a file from 1 folder to some other inwards Java. The alone caveat is that this requires JRE vii too compiled using Java 1.7 compiler.

 public static void copyFile(String from, String to) throws IOException{         Path src = Paths.get(from);         Path dest = Paths.get(to);         Files.copy(src.toFile(), dest.toFile());     }
 

It's equally uncomplicated equally the instant event but it doesn't require whatever third-party library inwards your classpath.  You tin farther specify re-create options to supersede existing file or usage criterion options. You tin farther read, The Well-Grounded Java Developer: Vital techniques of Java vii too polyglot programming, it nicely covers of import features of NIO 2.0 e.g. copying too moving files, watching a directory for alter too other essential features for Java programmers.

Java Program to re-create files from 1 directory to another

Here is our consummate Java programme to re-create a file or a laid of files from 1 directory to another.  It includes all 3 examples for copying a file inwards Java.

import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.nio.file.Path; import java.nio.file.Paths;  import org.apache.commons.io.FileUtils;  import com.google.common.io.Files;  /**  * How to write to a file using try-with-resource disceptation inwards Java.  *  * @author java67  */  public class FileCopyDemo {      public static void main(String args[]) throws IOException {                       File from = new File("programming.txt");         File to = new File("java6");                 System.out.println("Copying file inwards same place using FileInputStream");         copy(from, to);                 System.out.println("Copying file into some other place using Java vii Files.copy");         copyFile("programming.txt", "java7.txt");                 System.out.println("Copying file to some other directory using Apache common IO");         copyFileUsingApache(from, new File("apache.txt"));                     }      /**      * This method re-create a file from 1 directory to another. src is path of the      * file to re-create dest is the path where to re-create the file.      *      * @param src      * @param dest      * @throws IOException      */     public static void copy(File src, File dest) throws IOException {         InputStream is = null;         OutputStream os = null;         try {             is = new FileInputStream(src);             os = new FileOutputStream(dest);              // buffer size 1K             byte[] buf = new byte[1024];              int bytesRead;             while ((bytesRead = is.read(buf)) > 0) {                 os.write(buf, 0, bytesRead);             }         } finally {             is.close();             os.close();         }     }             /**      * Java vii agency to re-create a file from 1 place to some other      * @param from      * @param to      * @throws IOException      */     public static void copyFile(String from, String to) throws IOException{         Path src = Paths.get(from);         Path dest = Paths.get(to);         Files.copy(src.toFile(), dest.toFile());     }         /**      * Apache common IO FileUtils provides slow agency to re-create files inwards Java      * It internally uses File      * @param from      * @param string      * @throws IOException      */     public static void copyFileUsingApache(File from, File to) throws IOException{         FileUtils.copyFile(from, to);     } }  Output : Copying file in the same location using FileInputStream Copying file into some other location using Java vii Files.copy Copying file to some other directory using Apache common IO

You tin encounter that all 3 approach plant for a pocket-size file but it's the total regression test. You tin endeavour to a greater extent than past times copying large file too checking which event re-create the file faster.

Here is overnice summary of Java NIO.2 Features for copying too moving files too watching directories:

Important Points well-nigh Copying File inwards Java

1) The Files.copy() should live a criterion agency to re-create a file from 1 folder to another, if y'all are working inwards Java vii too Java 8.


2) For copying file inwards Java 6, y'all tin either write your ain code using FileChannel, FileInputStream or tin leverage Apache Commons IO. I would advise usage Apache Commons IO equally its tried too tested library too its best practise to usage the library instead of writing your ain code. Of course, this dominion doesn't apply to a rockstar developers who are great to optimize everything equally per their application need.


3) Use FileChannel to write a file re-create method inwards Java five too 6. It's real efficient too should live used to re-create large files from 1 house to other.


4) If source file does non be or y'all conduct maintain made spelling error our starting fourth dimension solution volition throw :

the starting fourth dimension solution volition throw :
Exception inwards thread "main" java.lang.NullPointerException
at dto.FileCopyDemo.copy(FileCopyDemo.java:65)
at dto.FileCopyDemo.main(FileCopyDemo.java:31)


Second solution volition throw :
Exception inwards thread "main" java.nio.file.NoSuchFileException: programming1.txt
at sun.nio.fs.WindowsException.translateToIOException(Unknown Source)
at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
at sun.nio.fs.WindowsFileCopy.copy(Unknown Source)
at sun.nio.fs.WindowsFileSystemProvider.copy(Unknown Source)
at java.nio.file.Files.copy(Unknown Source)
at dto.FileCopyDemo.copyFile(FileCopyDemo.java:80)
at dto.FileCopyDemo.main(FileCopyDemo.java:34)


too tertiary solution volition throw :
Exception inwards thread "main" java.io.FileNotFoundException: Source 'programming1.txt' does non exist
at org.apache.commons.io.FileUtils.copyFile(FileUtils.java:1074)
at org.apache.commons.io.FileUtils.copyFile(FileUtils.java:1038)
at dto.FileCopyDemo.copyFileUsingApache(FileCopyDemo.java:91)
at dto.FileCopyDemo.main(FileCopyDemo.java:37)


4) If the target file already exists too thus the starting fourth dimension solution volition silently overwrite it.

Second solution volition throw below exception:

Exception inwards thread "main" java.nio.file.FileAlreadyExistsException: target\java7.txt
at sun.nio.fs.WindowsFileCopy.copy(Unknown Source)
at sun.nio.fs.WindowsFileSystemProvider.copy(Unknown Source)
at java.nio.file.Files.copy(Unknown Source)
at dto.FileCopyDemo.copyFile(FileCopyDemo.java:80)
at dto.FileCopyDemo.main(FileCopyDemo.java:34)

y'all tin conduct maintain attention of it past times supplying the file re-create pick REPLACE_EXISTING inwards Java vii thought.


5) If target path doesn't be e.g. y'all desire to re-create inwards a directory which is non yet created too thus our starting fourth dimension solution volition throw

Exception inwards thread "main" java.lang.NullPointerException
at dto.FileCopyDemo.copy(Helloworld.java:66)

Second solution volition throw :
Exception inwards thread "main" java.nio.file.NoSuchFileException: programming.txt -> targetrr\java7.txt
at sun.nio.fs.WindowsException.translateToIOException(Unknown Source)
at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
at sun.nio.fs.WindowsFileCopy.copy(Unknown Source)
at sun.nio.fs.WindowsFileSystemProvider.copy(Unknown Source)
at java.nio.file.Files.copy(Unknown Source)
at dto.FileCopyDemo.copyFile(FileCopyDemo.java:80)
at dto.FileCopyDemo.main(FileCopyDemo.java:34)


too the tertiary solution volition do the directory too re-create the file there, 1 of the best solutions.


That's all well-nigh how to re-create a file inwards Java. If y'all are on Java 7, usage Files.copy() method, its uncomplicated too slow too y'all don't take away to include whatever tertiary political party library, but if y'all are running on Java 6, too thus y'all tin either usage Apache common IO library too FileUtils.copy() method or y'all tin write your ain routing using FileChannel to re-create file from 1 folder to some other inwards Java.


Other Java File too directory tutorials y'all may like

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• How to re-create a non-empty directory inwards Java? (example)
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• How to read a ZIP archive inwards Java? (solution)
• 2 ways to read a text file inwards Java? (example)
• How to append text to existing file inwards Java (solution)
• How to write to file using BufferedWriter inwards Java? (example)

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