14.5 Try-With-Resources

Try-With-Resources

In the last example, you had to close all your file streams explicitly in the finally block. Newer versions of Java have try-with-resources statements, where you specify which file/file streams you want to open, and then Java will automatically close them after the try/catch blocks.

Declare the file/file stream classes in parentheses () after the try keyword (don’t declare them separately outside of the block), and separate declarations with semicolons.


try (FileInputStream in = new FileInputStream(file);
    FileOutputStream out = new FileOutputStream("names_upper.txt")) {
           
	  int c;
    while ((c = in.read()) != -1) 
					out.write(Character.toUpperCase((char) c));

} catch (IOException e) {
    System.out.println("An IO Exception occurred.");
    e.printStackTrace(); // Prints error output stream.
}

💻 TryWithResources.java

💻 names_upper.txt

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14.4 File/IO

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6️⃣

14.6 BufferedReader

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