Mastering File Manipulation in Java
Getting Started with File Handling
To effectively work with files in Java, it’s essential to have a solid grasp of the Java File Class and Java Exception Handling concepts. Let’s dive into an example where we’ll append text to an existing file.
Setting the Stage
Assume we have a file named test.txt in our src folder, containing some initial content. Our goal is to add new text to this file without overwriting its existing content.
Example 1: Append Text Using System’s write() Method
By leveraging the System class’s user.dir property, we can retrieve the current directory and store it in the path variable. We’ll also define the text to be appended, stored in the text variable. Within a try-catch block, we’ll utilize the write() method to append the text to the existing file. This method takes three parameters: the file path, the text to be written, and the write mode (in this case, APPEND). Since the write() method may throw an IOException, we’ll catch the exception using a try-catch block.
The Result
When we run the program, the test.txt file will now contain the appended text.
Example 2: Append Text Using FileWriter
Alternatively, we can use a FileWriter object to achieve the same result. By creating a FileWriter instance and passing the file path and true as the second parameter, we enable file appending. Then, we’ll use the write() method to append the text and close the FileWriter. The output of this program will be identical to Example 1.
Key Takeaways
In this article, we’ve explored two approaches to appending text to an existing file in Java. By mastering these techniques, you’ll be well-equipped to handle more complex file manipulation tasks in your Java projects.