I/O resource opened but not safely closed

Reports I/O resources that are not safely closed. I/O resources checked by this inspection include java.io.InputStream, java.io.OutputStream, java.io.Reader, java.io.Writer, java.util.zip.ZipFile, java.io.Closeable and java.io.RandomAccessFile.

I/O resources wrapped by other I/O resources are not reported, as the wrapped resource will be closed by the wrapping resource.

By default, the inspection assumes that the resources can be closed by any method with 'close' or 'cleanup' in its name.

Example:

  void save() throws IOException {
    FileWriter writer = new FileWriter("filename.txt"); //warning
    writer.write("sample");
  }

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

IOResource

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Resource management

Use the following options to configure the inspection:

List I/O resource classes that do not need to be closed and should be ignored by this inspection.
Whether an I/O resource is allowed to be opened inside a tryblock. This style is less desirable because it is more verbose than opening a resource in front of a try block.
Whether the resource can be closed by any method call with the resource passed as argument.

Inspection options

Here you can find the description of settings available for the I/O resource opened but not safely closed inspection, and the reference of their default values.

Ignored I/O resource types: [java.io.ByteArrayOutputStream, java.io.ByteArrayInputStream, java.io.StringBufferInputStream, java.io.CharArrayWriter, java.io.CharArrayReader, java.io.StringWriter, java.io.StringReader]
Allow resource to be opened inside a 'try' block: Not selected
Any method may close resource argument: Default: Selected

Availability

By default bundled with: IntelliJ IDEA 2024.1, Qodana for JVM 2024.1,
Can be installed with plugin: Java, 241.18072

Last modified: 18 June 2024