# Reading and Writing Files in Java

By Atta Ur Rehman Shah (https://attacomsian.com/about). Published Dec 1, 2019, updated Dec 5, 2019. Topics: Java.
Canonical URL: https://attacomsian.com/blog/java-read-write-files

> A comprehensive guide to learn how to read and write text and binary files in Java.

One of the most common tasks while creating a software application is to read and write data to a file. The data could be stored in a [JSON file](https://attacomsian.com/blog/java-read-write-json-files), a [CSV file](https://attacomsian.com/blog/read-write-csv-files-core-java), a binary file, or in a [text file](https://attacomsian.com/blog/how-to-read-a-file-line-by-line-in-java).

In this article, you'll learn **how to read and write text and binary files** in Java. Java provides several APIs (unknown as **Java I/O**) for reading and writing files right from the beginning. Over the years, these APIs are further improved to provide a simplified and robust interface for dealing with different kinds of files.

## Reading Text Files in Java

If you want to read a simple text file, just use the `FileReader` class and wrap it in a `BufferedReader`. Here is an example that uses the `BufferedReader` class to read a file named `input.txt` line by line:

```java
try {
    // create a reader
    BufferedReader br = new BufferedReader(new FileReader("input.txt"));

    // read until end of file
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println(line);
    }

    // close the reader
    br.close();

} catch (IOException ex) {
    ex.printStackTrace();
}
```

> Check out [how to read a file line by line in Java](https://attacomsian.com/blog/how-to-read-a-file-line-by-line-in-java) tutorial for more examples.

## Reading Binary Files in Java

If you want to read a binary file or a file containing special characters, you need to use the `FileInputStream` class instead of `FileReader`. Here is an example:

```java
try {
    // create a reader
    FileInputStream fis = new FileInputStream(new File("input.dat"));

    // read until end of file
    int ch;
    while ((ch = fis.read()) != -1) {
        System.out.print((char) ch);
    }

    // close the reader
    fis.close();

} catch (IOException ex) {
    ex.printStackTrace();
}
```

## Writing Text Files in Java

To write a text file in Java, you should use the `FileWriter` class and wrap it in a `BufferedWriter` as shown below:

```java
try {
    // create a writer
    BufferedWriter bw = new BufferedWriter(new FileWriter("output.txt"));

    // write text to file
    bw.write("Hey, there!");
    bw.newLine();
    bw.write("See you soon.");

    // close the writer
    bw.close();

} catch (IOException ex) {
    ex.printStackTrace();
}
```

The above code will create a new file named `output.txt` with the following contents:

```plaintext
Hey, there!
See you soon.
```

## Writing Binary Files in Java

You can easily create and write to a binary file in Java by using the `FileOutputStream` class. Here is an example that creates a new binary file and writes data into it:

```java
try {
    // create a writer
    FileOutputStream fos = new FileOutputStream(new File("output.dat"));

    // write data to file
    fos.write("Hey, there!".getBytes());
    fos.write("\n".getBytes());
    fos.write("See you soon.".getBytes());

    // close the writer
    fos.close();

} catch (IOException ex) {
    ex.printStackTrace();
}
```