#file Archives - Programmer Gate

August 29, 2018

How to write to a plain text file in Java

This tutorial shows several ways to write content to a text file in Java. The techniques used below are pure JDK and don’t use external libraries. 1- BufferedWriter The most common and efficient way to write content to a file in Java is through using BufferedWriter as the following:

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private static void writeFileUsingBufferedWriter()

{

try(Writer writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("new-file.txt"), "UTF-8")))

{

writer.write("First Line");

writer.write("\n");

writer.write("Second Line");

}

catch(IOException ex)

{

ex.printStackTrace();

}

This technique is very efficient for writing huge data to...

Java core

August 29, 2018

How to read a plain text file in Java

This tutorial shows several ways for reading plain text files in Java. The techniques we use here are totally JDK built-in and don’t depend on external libraries. 1- BufferedReader The most common way for reading plain text files in Java is through using a FileReader wrapped by a BufferedReader. This technique is very efficient for reading large text files.

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private static void readFileUsingBufferedReader(String filePath)

{

try(BufferedReader br = new BufferedReader(new FileReader(filePath)))

{

String line = null;

while ((line = br.readLine()) != null)

{

System.out.println(line);

}

catch (IOException e)

{

e.printStackTrace();

}

...

Java core

July 29, 2018

Java – Convert File to byte[]

This tutorial shows several ways to convert a File object to a byte[] array in Java. 1- Traditional way The traditional conversion way is through using read() method of InputStream as the following:

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public static byte[] convertUsingTraditionalWay(File file)

{

byte[] fileBytes = new byte[(int) file.length()];

try(FileInputStream inputStream = new FileInputStream(file))

{

inputStream.read(fileBytes);

}

catch (Exception ex)

{

ex.printStackTrace();

}

return fileBytes;

}

2- Java NIO With Java 7, you can do the conversion using Files utility class of nio package:

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public static byte[] convertUsingJavaNIO(File file)

{

byte[] fileBytes = null;

try

{

fileBytes = Files.readAllBytes(file.toPath());

}

catch (Exception ex)

{

ex.printStackTrace();

}

return fileBytes;

}

3- Apache Commons IO Besides JDK, you can...

Java core

July 29, 2018

Java – Convert byte[] to File

This tutorial shows several ways to convert a byte[] array to File in Java. 1- Traditional way The traditional way of doing the conversion is through using FileOutputStream as the following:

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public static File convertUsingOutputStream(byte[] fileBytes)

{

File f = new File("C:\\Users\\user\\Desktop\\output\\myfile.pdf");

try (FileOutputStream fos = new FileOutputStream(f)) {

fos.write(fileBytes);

}

catch(Exception ex)

{

ex.printStackTrace();

}

return f;

}

2- Java NIO With Java 7, you can do the conversion using Files utility class of nio package:

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public static File convertUsingJavaNIO(byte[] fileBytes)

{

File f = new File("C:\\Users\\user\\Desktop\\output\\myfile.pdf");

try

{

Files.write(f.toPath(), fileBytes);

}

catch (Exception ex)

{

ex.printStackTrace();

}

return f;

}

3- Apache Commons IO Besides JDK, you can do...

Tagged: #file

How to write to a plain text file in Java

How to read a plain text file in Java

Java – Convert File to byte[]

Java – Convert byte[] to File

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