- All Known Subinterfaces:
AsynchronousByteChannel,AsynchronousChannel,BaseStream<T,S>,ByteChannel,CachedRowSet,CallableStatement,Channel,Clip,Closeable,Connection,DataLine,DirectoryStream<T>,DoubleStream,ExecutionControl,FilteredRowSet,GatheringByteChannel,ImageInputStream,ImageOutputStream,InterruptibleChannel,IntStream,JavaFileManager,JdbcRowSet,JMXConnector,JoinRowSet,Line,LongStream,MidiDevice,MidiDeviceReceiver,MidiDeviceTransmitter,Mixer,ModuleReader,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
- All Known 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,DirectExecutionControl,FileCacheImageInputStream,FileCacheImageOutputStream,FileChannel,FileImageInputStream,FileImageOutputStream,FileInputStream,FileLock,FileOutputStream,FileReader,FileSystem,FileWriter,FilterInputStream,FilterOutputStream,FilterReader,FilterWriter,Formatter,ForwardingJavaFileManager,GZIPInputStream,GZIPOutputStream,ImageInputStreamImpl,ImageOutputStreamImpl,InflaterInputStream,InflaterOutputStream,InputStream,InputStreamReader,JarFile,JarInputStream,JarOutputStream,JdiDefaultExecutionControl,JdiExecutionControl,JShell,LineNumberInputStream,LineNumberReader,LocalExecutionControl,LogStream,MemoryCacheImageInputStream,MemoryCacheImageOutputStream,MLet,MulticastSocket,ObjectInputStream,ObjectOutputStream,OutputStream,OutputStreamWriter,Pipe.SinkChannel,Pipe.SourceChannel,PipedInputStream,PipedOutputStream,PipedReader,PipedWriter,PrintStream,PrintWriter,PrivateMLet,ProgressMonitorInputStream,PushbackInputStream,PushbackReader,RandomAccessFile,Reader,Recording,RecordingFile,RemoteExecutionControl,RMIConnectionImpl,RMIConnectionImpl_Stub,RMIConnector,RMIIIOPServerImpl,RMIJRMPServerImpl,RMIServerImpl,Scanner,SctpChannel,SctpMultiChannel,SctpServerChannel,SelectableChannel,Selector,SequenceInputStream,ServerSocket,ServerSocketChannel,Socket,SocketChannel,SSLServerSocket,SSLSocket,StreamingExecutionControl,StringBufferInputStream,StringReader,StringWriter,SubmissionPublisher,URLClassLoader,URLReader,Writer,XMLDecoder,XMLEncoder,ZipFile,ZipInputStream,ZipOutputStream
public interfaceAutoCloseableAn object that may hold resources (such as file or socket handles) until it is closed. Theclose()method of anAutoCloseableobject is called automatically when exiting atry-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.- API Note:
It is possible, and in fact common, for a base class to implement AutoCloseable even though not all of its subclasses or instances will hold releasable resources. For code that must operate in complete generality, or when it is known that the
AutoCloseableinstance requires resource release, it is recommended to usetry-with-resources constructions. However, when using facilities such asStreamthat support both I/O-based and non-I/O-based forms,try-with-resources blocks are in general unnecessary when using non-I/O-based forms.- Since:
- 1.7
Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description voidclose()Closes this resource, relinquishing any underlying resources.
Method Detail
close
void close() throwsException
Closes this resource, relinquishing any underlying resources. This method is invoked automatically on objects managed by thetry-with-resources statement.While this interface method is declared to throw
Exception, implementers arestrongly encouraged to declare concrete implementations of theclosemethod 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 internallymark the resource as closed, prior to throwing the exception. The
closemethod 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
closemethod throwInterruptedException. This exception interacts with a thread's interrupted status, and runtime misbehavior is likely to occur if anInterruptedExceptionissuppressed. More generally, if it would cause problems for an exception to be suppressed, theAutoCloseable.closemethod should not throw it.Note that unlike the
closemethod ofCloseable, thisclosemethod isnot required to be idempotent. In other words, calling thisclosemethod more than once may have some visible side effect, unlikeCloseable.closewhich is required to have no effect if called more than once. However, implementers of this interface are strongly encouraged to make theirclosemethods idempotent.- Throws:
Exception- if this resource cannot be closed