Java Create New File With Text

• Java Create New File Example
• Java Create New File With Text Reader
• Java Print To Text File
• Create Text File Java

This example demonstrates the way of creating a new file by using File constructor and file.createNewFile method of File class. Java file writing FAQ: How do I append text to the end of a text file in Java? The short answer is that you create a FileWriter instance with the append flag set to true, like this: BufferedWriter bw = new BufferedWriter(new FileWriter('checkbook.dat', true)); The rest of this article explains this. A sample data file. How to Create a File in Java. In Java, creating a file is easy by using pre-defined classes and packages. There are three ways to create a file. Using File.createNewFile method; Using FileOutputStream class; Using File.createFile method; Java File.createNewFile method. The File.createNewFile is a method of File class which belongs to a java.io package. It does not accept any argument. In Java, there are many ways to create and write to a file. Files.newBufferedWriter (Java 8); Files.write (Java 7); PrintWriter; File.createNewFile; Note I prefer the Java 7 nio Files.write to create and write to a file, because it has much cleaner code and auto close the opened resources.

In Java, we can use the following two Files.createTempFile() methods to create a temporary file in the default temporary-file directory.

The default temporary file folder is vary on operating system.

1. Windows – %USER%AppDataLocalTemp
2. Linux – /tmp

1. Create Temporary Files

1.1 This example uses Files.createTempFile(prefix, suffix) to create a temporary file. If the suffix is null, the default is .tmp.

Output

1.2 prefix = null, suffix = '.log'

1.3 prefix = 'hello', suffix = null

1.4 prefix = 'hello', suffix = '

1.5 prefix = null, suffix = null

2. Create Temporary Files in a specified directory

2.1 In Java, we can pass a java.nio.file.Path to Files.createTempFile to create a temporary file in a specified directory.

Output

If the specified folder does not exist, Java throws NoSuchFileException.

3. Create Temporary Files + File Permission

3.1 This example tries to assign 777 file permission during temporary file creation.

Output – On Unix, the group writes file permission may not work as expected.

To fix it, create the temporary file first, and assign the file permission to the temporary file later.

To fix it, create the temporary file first, and assign the file permission to the temporary file later.

Output

4. Create Temporary Files + Java Legacy IO

This example uses the legacy Java IO java.io.* to create a temporary file, it still works perfectly, but the new Java NIO should always be the first choice.

Output

Download Source Code

$ git clone https://github.com/mkyong/core-java

$ cd java-io

References

• How to get the temporary file path in Java.

There are many times during our project work we need to read a text file in java. There are many ways to read a text file in java. One can use FileReader, BufferedReader and Scanner to read a text file.

Java Create New File Example

Java 8 introduced Stream class java.util.stream.Stream which gives a lazy and more efficient way to read a file line by line.

BufferedReader uses buffering of data for very fast reading.

Reading a text file using BufferedReader

BufferedReader is very simple and high performance technique of reading text files in Java. It reads the text from a character input stream. It does the buffering of characters, arrays and lines for efficient reading.

The buffer size can be specified or the default size can be used.

Java Create New File With Text Reader

Using try with resource and nio

Reading a text file using FileReader

Java Print To Text File

FileReader is used for reading streams of characters. For reading streams of raw bytes, try using a FileInputStream.

Reading a text file using Scanner

Java read file line by line using Files.readAllLines()

Files.readAllLines() is a method of the Java NIO Files class which reads all the lines of a file and then returns a List containing each line. Internally it uses BufferedReader to read the file.

Java read file line by line using Files.lines()

Files.lines() method reads all the lines from the file as Stream. Stream API methods can be used like forEach, map to get record with each line of the file.

Java read file into byte using Files.readAllBytes()

News explorer 1 9 7 esv. It reads all bytes from a file.

This method ensures that file is closed when all bytes had been read or an I/O error, or other runtime exception, is thrown.

This method should be used for simple needs where it is easy to read all bytes into a byte array. It should not be used for reading in large files.

Create Text File Java

It throws

IOException – if an I/O error occurs while reading from the stream

OutOfMemoryError – If file size is more than 2 GB then this error will be thrown.

SecurityException –checkRead method will be invoked to check read access to the file.

Conclusion

That's all readers. You have learned how to read a text file in java.