Java is an object-oriented programming language, designed to create programs that are lightweight and platform independent. Java is so widely used because it is both powerful and easy to use and understand. In this article, we will discuss how to use the BufferedWriter class in Java and provide an example.

Introduction to BufferedWriter

The Java BufferedWriter class is used for writing text to character output streams. It’s used when there is a need to write bulk data to a file, such as when writing log files, HTML files, and configuration files. BufferedWriter provides better performance because it writes data to a buffer, instead of writing it directly to a file or other output stream. This helps reduce the amount of time a program takes to write data and makes it more efficient.

The BufferedWriter class also provides methods for writing single characters, arrays of characters, and strings. It also provides methods for writing lines of text, which is useful for writing text files. Additionally, the BufferedWriter class provides methods for flushing the buffer, which is useful for ensuring that all data is written to the output stream before the program exits.

What is BufferedWriter?

The BufferedWriter class is a java.io class that is used to write text to a character-based output stream. It was introduced in the JDK 1.1 release. The BufferedWriter class makes it easy to write text to buffered output streams such as files. It also provides better performance, as data is buffered in memory before it is written.

The BufferedWriter class is often used in combination with the FileWriter class, which is used to write data to a file. The BufferedWriter class provides additional methods for writing text, such as the writeLine() method, which allows you to write a line of text to the output stream. It also provides methods for flushing the buffer, which is useful when you want to ensure that all data is written to the output stream.

Benefits of Using BufferedWriter

One of the main benefits of using the BufferedWriter class is its improved performance. By writing data to a memory buffer, instead of directly to a file, a computer can save time and resources. This is especially useful when writing large quantities of data, such as log files or HTML files. Additionally, the BufferedWriter class allows you to write data in specific encoding formats, such as UTF-8 and ISO-8859-1.

The BufferedWriter class also provides a convenient way to write data to a file in a structured way. For example, you can use the write() method to write a single line of text to a file, or the newLine() method to write a line break. This makes it easier to create files with a consistent format, such as CSV files or XML files.

Creating a BufferedWriter Object

Creating a BufferedWriter object is a simple process. The most basic constructor takes a single parameter: the OutputStream or Writer object that the data should be written to. The following code creates a BufferedWriter object and assigns it to the variable bw:

BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

In this example, we are creating the BufferedWriter object with an OutputStreamWriter object that is writing data to System.out. We could also pass in a FileWriter object, for example, if we wanted to write text data to a file.

It is also possible to create a BufferedWriter object with a custom buffer size. This can be done by passing in an additional parameter to the constructor, specifying the size of the buffer. For example, the following code creates a BufferedWriter object with a buffer size of 8192 bytes:

BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out), 8192);

Writing Data with a BufferedWriter Object

It is easy to write data with a BufferedWriter object. To write data, simply call the write() method with the character or string that you want to write. You can also use the writeLine() method to write a line of text with a system-dependent line terminator. The following code writes the character ‘a’ to System.out:

bw.write('a');

Once you are finished writing data, you should call the flush() or close() method on the object. This will ensure any remaining buffered data is written and that any associated resources are properly released.

It is important to note that the BufferedWriter object is not thread-safe. If you are writing data from multiple threads, you should use a separate BufferedWriter object for each thread. Additionally, you should always wrap the BufferedWriter object in a try-with-resources block to ensure that the object is properly closed when you are finished writing data.

Closing a BufferedWriter Object

Once you are finished writing data with the BufferedWriter object, it’s important to close it. This will ensure that any remaining buffered data is written and that any associated resources are properly released. To close a BufferedWriter object, simply call the close() method:

bw.close();

It is important to note that the close() method may throw an IOException if an error occurs while closing the BufferedWriter object. Therefore, it is recommended to use a try-catch block when calling the close() method, to ensure that any errors are properly handled.

Flushing a BufferedWriter Object

If you don’t want to close the BufferedWriter object but need to ensure that any buffered data has been written to its destination, you can call the flush() method instead. This will clear the buffer and make sure all data has been written:

bw.flush();

It is important to note that the flush() method does not close the BufferedWriter object. To close the object, you must call the close() method. Additionally, the flush() method does not guarantee that all data has been written to the destination. It only ensures that the data in the buffer has been written.

Example of Using a BufferedWriter Object

Now let’s see an example of using the BufferedWriter class to write text data to a file. The following code will create a file called “example.txt” in the current directory and write the string “Hello World!” to it:

BufferedWriter bw = new BufferedWriter(new FileWriter("example.txt"));bw.write("Hello World!");bw.close();

Once this code has been executed, a file called “example.txt” should now exist in the current directory with the contents “Hello World!”.

It is important to note that the BufferedWriter class is used to write text data to a file. It is not suitable for writing binary data, such as images or audio files. For this, you should use the FileOutputStream class.

Conclusion

In this article, we looked at how to use the BufferedWriter class in Java for writing text data to files and streams. We discussed the benefits of using BufferedWriter, showed how to create and write with one, and provided an example of writing a string to a file. Understanding how to use the BufferedWriter class is an important part of any Java programmer’s toolkit.

In addition to the BufferedWriter class, there are other classes available in Java for writing text data to files and streams. For example, the PrintWriter class can be used to write formatted text data to a file or stream. It is important to understand the differences between these classes and how to use them in order to write efficient and effective code.