Does DocumentBuilder.parse Automatically Close the InputStream?

Does DocumentBuilder.parse automatically close the InputStream?

// Example InputStream usage
InputStream inputStream = new FileInputStream("file.xml");
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
try {
    Document doc = builder.parse(inputStream);
} catch (Exception e) {
    e.printStackTrace();
} // What happens to the InputStream after this?

The DocumentBuilder.parse method in Java does not close the InputStream that it takes as an argument. This behavior is important to understand when working with resources, as failing to close an InputStream can lead to resource leaks and potential memory issues in your applications.

try (InputStream inputStream = new FileInputStream("file.xml")) {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document doc = builder.parse(inputStream);
} catch (Exception e) {
    e.printStackTrace();
} // Automatic closing of inputStream happens here.

Causes

• You are not closing the InputStream after parsing the XML document.
• The method signature for DocumentBuilder.parse does not state that it closes the InputStream.

Solutions

• Always wrap the InputStream in a try-with-resources statement or explicitly close it in a finally block.
• Use inputStream.close() after you are done using it to avoid resource leaks.

Mistake: Ignoring to close the InputStream, which leads to resource leaks.

Solution: Always ensure that you close the InputStream using try-with-resources or a finally block.

Mistake: Assuming parse will manage the InputStream lifecycle.

Solution: Understand that parse does not manage the InputStream, and it's the developer's responsibility.