Java Create New File With Text

• How To Create A File With Some Text In Linux

There are various ways in which you can create a new file in Java. In this article, I've outlined the two most recommended way of creating new files.

A new empty file with the required abstract path name can be created using the method java.io.File.createNewFile. This method requires no parameters and it returns true if the file is newly created and it did not exist previously. The java.io package contains nearly every class you might ever need to perform input and output (I/O) in Java. All these streams represent an input source and an output destination. The stream in the java.io package supports many data such as primitives, object, localized characters, etc. The tutorials shows five ways to create a file in Java. The examples create empty files. Java creating file with File. The File's createNewFile method creates a new, empty file named by the pathname if a file with this name does not yet exist.

Create New file using Java NIO (Recommended) - JDK 7+

You can use Files.createFile(path) method to create a new File in Java:

Create New File with missing parent directories using Java NIO

There are scenarios in which you may want to create any missing parent directories while creating a File. Macbook air remote desktop to windows. You can use Files.createDirectories(path) function to create missing parent directories before creating the file.

Create New File in Java using java.io.File class - JDK 6+

You can also use the File.createNewFile() method to create a new File in Java. It returns a boolean value which is -

• true, if the file does not exist and was created successfully
• false, if the file already exists

Create New File along with missing parent directories with java.io.File class

If you want to create missing parent directories while creating a file, then you can explicitly creaate the directories by calling file.getParentFile().mkdirs() method:

• true, if the file does not exist and was created successfully
• false, if the file already exists

Create New File along with missing parent directories with java.io.File class

If you want to create missing parent directories while creating a file, then you can explicitly creaate the directories by calling file.getParentFile().mkdirs() method:

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The java.io package contains nearly every class you might ever need to perform input and output (I/O) in Java. All these streams represent an input source and an output destination. The stream in the java.io package supports many data such as primitives, object, localized characters, etc.

Stream

A stream can be defined as a sequence of data. There are two kinds of Streams −

• InPutStream − The InputStream is used to read data from a source.

• OutPutStream − The OutputStream is used for writing data to a destination.

Java provides strong but flexible support for I/O related to files and networks but this tutorial covers very basic functionality related to streams and I/O. We will see the most commonly used examples one by one −

Byte Streams

Java byte streams are used to perform input and output of 8-bit bytes. Though there are many classes related to byte streams but the most frequently used classes are, FileInputStream and FileOutputStream. Following is an example which makes use of these two classes to copy an input file into an output file −

Example

Now let's have a file input.txt with the following content −

As a next step, compile the above program and execute it, which will result in creating output.txt file with the same content as we have in input.txt. So let's put the above code in CopyFile.java file and do the following −

Character Streams

Java Byte streams are used to perform input and output of 8-bit bytes, whereas Java Character streams are used to perform input and output for 16-bit unicode. Though there are many classes related to character streams but the most frequently used classes are, FileReader and FileWriter. Though internally FileReader uses FileInputStream and FileWriter uses FileOutputStream but here the major difference is that FileReader reads two bytes at a time and FileWriter writes two bytes at a time.

We can re-write the above example, which makes the use of these two classes to copy an input file (having unicode characters) into an output file −

Example

Now let's have a file input.txt with the following content −

As a next step, compile the above program and execute it, which will result in creating output.txt file with the same content as we have in input.txt. So let's put the above code in CopyFile.java file and do the following −

Standard Streams

All the programming languages provide support for standard I/O where the user's program can take input from a keyboard and then produce an output on the computer screen. If you are aware of C or C++ programming languages, then you must be aware of three standard devices STDIN, STDOUT and STDERR. Similarly, Java provides the following three standard streams −

• Standard Input − This is used to feed the data to user's program and usually a keyboard is used as standard input stream and represented as System.in.

• Standard Output − This is used to output the data produced by the user's program and usually a computer screen is used for standard output stream and represented as System.out.

• Standard Error − This is used to output the error data produced by the user's program and usually a computer screen is used for standard error stream and represented as System.err.

Following is a simple program, which creates InputStreamReader to read standard input stream until the user types a 'q' −

Example

Let's keep the above code in ReadConsole.java file and try to compile and execute it as shown in the following program. This program continues to read and output the same character until we press 'q' −

Reading and Writing Files

As described earlier, a stream can be defined as a sequence of data. The InputStream is used to read data from a source and the OutputStream is used for writing data to a destination.

Here is a hierarchy of classes to deal with Input and Output streams.

The two important streams are FileInputStream and FileOutputStream, which would be discussed in this tutorial.

FileInputStream

This stream is used for reading data from the files. Objects can be created using the keyword new and there are several types of constructors available.

Following constructor takes a file name as a string to create an input stream object to read the file −

Following constructor takes a file object to create an input stream object to read the file. First we create a file object using File() method as follows −

Once you have InputStream object in hand, then there is a list of helper methods which can be used to read to stream or to do other operations on the stream.

There are other important input streams available, for more detail you can refer to the following links −

FileOutputStream

FileOutputStream is used to create a file and write data into it. The stream would create a file, if it doesn't already exist, before opening it for output.

Here are two constructors which can be used to create a FileOutputStream object.

Following constructor takes a file name as a string to create an input stream object to write the file −

Following constructor takes a file object to create an output stream object to write the file. First, we create a file object using File() method as follows −

Once you have OutputStream object in hand, then there is a list of helper methods, which can be used to write to stream or to do other operations on the stream.

There are other important output streams available, for more detail you can refer to the following links −

Example

Following is the example to demonstrate InputStream and OutputStream −

The above code would create file test.txt and would write given numbers in binary format. Same would be the output on the stdout screen.

File Navigation and I/O

There are several other classes that we would be going through to get to know the basics of File Navigation and I/O.

Directories in Java

A directory is a File which can contain a list of other files and directories. You use File object to create directories, to list down files available in a directory. For complete detail, check a list of all the methods which you can call on File object and what are related to directories.

Creating Directories

There are two useful File utility methods, which can be used to create directories −

• The mkdir( ) method creates a directory, returning true on success and false on failure. Failure indicates that the path specified in the File object already exists, or that the directory cannot be created because the entire path does not exist yet.

• The mkdirs() method creates both a directory and all the parents of the directory.

Following example creates '/tmp/user/java/bin' directory −

Example

Compile and execute the above code to create '/tmp/user/java/bin'.

Note − Java automatically takes care of path separators on UNIX and Windows as per conventions. If you use a forward slash (/) on a Windows version of Java, the path will still resolve correctly.

Listing Directories

You can use list( ) method provided by File object to list down all the files and directories available in a directory as follows −

Example

This will produce the following result based on the directories and files available in your /tmp directory −

How To Create A File With Some Text In Linux

Output