AutoCloseable in Java

java.lang.AutoCloseable

An object that may hold resources (such as file or socket handles) until it is closed. The close() method of an AutoCloseable object is called automatically when exiting a try-with-resources block for which the object has been declared in the resource specification header. This construction ensures prompt release, avoiding resource exhaustion exceptions and errors that may otherwise occur.

Subinterfaces:

AsynchronousByteChannel, AsynchronousChannel, BaseStream<T,S>, ByteChannel, CachedRowSet, CallableStatement, Channel, Clip, Closeable,Connection, DataLine, DirectoryStream<T>, DoubleStream, FilteredRowSet,GatheringByteChannel, ImageInputStream, ImageOutputStream,InterruptibleChannel, IntStream, JavaFileManager, JdbcRowSet, JMXConnector,JoinRowSet, Line, LongStream, MidiDevice, MidiDeviceReceiver,MidiDeviceTransmitter, Mixer, MulticastChannel, NetworkChannel, ObjectInput,ObjectOutput, Port, PreparedStatement, ReadableByteChannel, Receiver,ResultSet, RMIConnection, RowSet, ScatteringByteChannel,SecureDirectoryStream<T>, SeekableByteChannel, Sequencer, SourceDataLine,StandardJavaFileManager, Statement, Stream<T>, SyncResolver, Synthesizer,TargetDataLine, Transmitter, WatchService, WebRowSet, WritableByteChannel

Implementing Classes:

AbstractInterruptibleChannel,AbstractSelectableChannel, AbstractSelector, AsynchronousFileChannel,AsynchronousServerSocketChannel, AsynchronousSocketChannel, AudioInputStream,BufferedInputStream, BufferedOutputStream, BufferedReader, BufferedWriter,ByteArrayInputStream, ByteArrayOutputStream, CharArrayReader,CharArrayWriter, CheckedInputStream, CheckedOutputStream, CipherInputStream,CipherOutputStream, DatagramChannel, DatagramSocket, DataInputStream,DataOutputStream, DeflaterInputStream, DeflaterOutputStream,DigestInputStream, DigestOutputStream, FileCacheImageInputStream,FileCacheImageOutputStream, FileChannel, FileImageInputStream,FileImageOutputStream, FileInputStream, FileLock, FileOutputStream,FileReader, FileSystem, FileWriter, FilterInputStream, FilterOutputStream,FilterReader, FilterWriter, Formatter, ForwardingJavaFileManager,GZIPInputStream, GZIPOutputStream, ImageInputStreamImpl,ImageOutputStreamImpl, InflaterInputStream, InflaterOutputStream,InputStream, InputStream, InputStream, InputStreamReader, JarFile,JarInputStream, JarOutputStream, LineNumberInputStream, LineNumberReader,LogStream, MemoryCacheImageInputStream, MemoryCacheImageOutputStream, MLet,MulticastSocket, ObjectInputStream, ObjectOutputStream, OutputStream,OutputStream, OutputStream, OutputStreamWriter, Pipe.SinkChannel,Pipe.SourceChannel, PipedInputStream, PipedOutputStream, PipedReader,PipedWriter, PrintStream, PrintWriter, PrivateMLet,ProgressMonitorInputStream, PushbackInputStream, PushbackReader,RandomAccessFile, Reader, RMIConnectionImpl, RMIConnectionImpl_Stub,RMIConnector, RMIIIOPServerImpl,SelectableChannel, Selector, SequenceInputStream, ServerSocket,ServerSocketChannel, Socket, SocketChannel, SSLServerSocket, SSLSocket, StringBufferInputStream, StringReader, StringWriter, URLClassLoader, Writer,XMLDecoder, XMLEncoder, ZipFile, ZipInputStream, ZipOutputStream

Declaration

public interface AutoCloseable {

    void close() throws Exception;
}

Methods

1. close()

void java.lang.AutoCloseable.close() throws Exception

Closes this resource, relinquishing any underlying resources. This method is invoked automatically on objects managed by the try-with-resources statement.

While this interface method is declared to throw an Exception, implementers are strongly encouraged to declare concrete implementations of the close method to throw more specific exceptions, or to throw no exception at all if the close operation cannot fail.

Cases, where the close operation may fail, require careful attention by implementers. It is strongly advised to relinquish the underlying resources and to internally mark the resource as closed, prior to throwing the exception. The close method is unlikely to be invoked more than once and so This ensures that the resources are released in a timely manner. Furthermore it reduces problems that could arise when the resource wraps or is wrapped, by another resource.

Implementers of this interface are also strongly advised to not have the close method throw InterruptedException.This exception interacts with a thread's interrupted status  and runtime misbehavior is likely to occur if an InterruptedException is suppressed.