IOException

AI-generated Key Takeaways

• IOException is a general exception class signaling failed or interrupted input/output operations in Java.

• It serves as the parent class for many more specific I/O exception types, like FileNotFoundException and EOFException.

• IOException can be constructed with an optional detailed message and/or a cause for the exception.

• It inherits methods from Throwable for handling stack traces and related diagnostic information.

• Developers can use IOException to catch and handle a broad range of I/O errors, or use its subclasses for more targeted error management.

public class IOException extends Exception

Known Direct Subclasses CharConversionException, CharacterCodingException, ClosedChannelException, EOFException, FileLockInterruptionException, FileNotFoundException, FileSystemException, HttpRetryException, InterruptedByTimeoutException, InterruptedIOException, InvalidPropertiesFormatException, MalformedURLException, ObjectStreamException, ProtocolException, SSLException, and 8 others. CharConversionException Base class for character conversion exceptions.  CharacterCodingException Checked exception thrown when a character encoding or decoding error occurs.  ClosedChannelException Checked exception thrown when an attempt is made to invoke or complete an I/O operation upon channel that is closed, or at least closed to that operation.  EOFException Signals that an end of file or end of stream has been reached unexpectedly during input.  FileLockInterruptionException Checked exception received by a thread when another thread interrupts it while it is waiting to acquire a file lock.  FileNotFoundException Signals that an attempt to open the file denoted by a specified pathname has failed.  FileSystemException Thrown when a file system operation fails on one or two files.  HttpRetryException Thrown to indicate that a HTTP request needs to be retried but cannot be retried automatically, due to streaming mode being enabled.  InterruptedByTimeoutException Checked exception received by a thread when a timeout elapses before an asynchronous operation completes.  InterruptedIOException Signals that an I/O operation has been interrupted.  InvalidPropertiesFormatException Thrown to indicate that an operation could not complete because the input did not conform to the appropriate XML document type for a collection of properties, as per the Properties specification.  MalformedURLException Thrown to indicate that a malformed URL has occurred.  ObjectStreamException Superclass of all exceptions specific to Object Stream classes.  ProtocolException Thrown to indicate that there is an error in the underlying protocol, such as a TCP error.  SSLException Indicates some kind of error detected by an SSL subsystem.  SocketException Thrown to indicate that there is an error creating or accessing a Socket.  SyncFailedException Signals that a sync operation has failed.  UTFDataFormatException Signals that a malformed string in modified UTF-8 format has been read in a data input stream or by any class that implements the data input interface.  UnknownHostException Thrown to indicate that the IP address of a host could not be determined.  UnknownServiceException Thrown to indicate that an unknown service exception has occurred.  UnsupportedEncodingException The Character Encoding is not supported.  UserPrincipalNotFoundException Checked exception thrown when a lookup of UserPrincipal fails because the principal does not exist.  ZipException Signals that a Zip exception of some sort has occurred.

Known Indirect Subclasses AccessDeniedException, AsynchronousCloseException, AtomicMoveNotSupportedException, BindException, ClosedByInterruptException, ConnectException, DirectoryNotEmptyException, FileAlreadyExistsException, FileSystemLoopException, InvalidClassException, InvalidObjectException, JarException, MalformedInputException, NoRouteToHostException, NoSuchFileException, and 14 others. AccessDeniedException Checked exception thrown when a file system operation is denied, typically due to a file permission or other access check.  AsynchronousCloseException Checked exception received by a thread when another thread closes the channel or the part of the channel upon which it is blocked in an I/O operation.  AtomicMoveNotSupportedException Checked exception thrown when a file cannot be moved as an atomic file system operation.  BindException Signals that an error occurred while attempting to bind a socket to a local address and port.  ClosedByInterruptException Checked exception received by a thread when another thread interrupts it while it is blocked in an I/O operation upon a channel.  ConnectException Signals that an error occurred while attempting to connect a socket to a remote address and port.  DirectoryNotEmptyException Checked exception thrown when a file system operation fails because a directory is not empty.  FileAlreadyExistsException Checked exception thrown when an attempt is made to create a file or directory and a file of that name already exists.  FileSystemLoopException Checked exception thrown when a file system loop, or cycle, is encountered.  InvalidClassException Thrown when the Serialization runtime detects one of the following problems with a Class.  InvalidObjectException Indicates that one or more deserialized objects failed validation tests.  JarException Signals that an error of some sort has occurred while reading from or writing to a JAR file.  MalformedInputException Checked exception thrown when an input byte sequence is not legal for given charset, or an input character sequence is not a legal sixteen-bit Unicode sequence.  NoRouteToHostException Signals that an error occurred while attempting to connect a socket to a remote address and port.  NoSuchFileException Checked exception thrown when an attempt is made to access a file that does not exist.  NotActiveException Thrown when serialization or deserialization is not active.  NotDirectoryException Checked exception thrown when a file system operation, intended for a directory, fails because the file is not a directory.  NotLinkException Checked exception thrown when a file system operation fails because a file is not a symbolic link.  NotSerializableException Thrown when an instance is required to have a Serializable interface.  OptionalDataException Exception indicating the failure of an object read operation due to unread primitive data, or the end of data belonging to a serialized object in the stream.  PortUnreachableException Signals that an ICMP Port Unreachable message has been received on a connected datagram.  SSLHandshakeException Indicates that the client and server could not negotiate the desired level of security.  SSLKeyException Reports a bad SSL key.  SSLPeerUnverifiedException Indicates that the peer's identity has not been verified.  SSLProtocolException Reports an error in the operation of the SSL protocol.  SocketTimeoutException Signals that a timeout has occurred on a socket read or accept.  StreamCorruptedException Thrown when control information that was read from an object stream violates internal consistency checks.  UnmappableCharacterException Checked exception thrown when an input character (or byte) sequence is valid but cannot be mapped to an output byte (or character) sequence.  WriteAbortedException Signals that one of the ObjectStreamExceptions was thrown during a write operation.

Signals that an I/O exception of some sort has occurred. This class is the general class of exceptions produced by failed or interrupted I/O operations.

See Also

• InputStream
• OutputStream

Public Constructor Summary

	IOException() Constructs an IOException with null as its error detail message.
	IOException(String message) Constructs an IOException with the specified detail message.
	IOException(String message, Throwable cause) Constructs an IOException with the specified detail message and cause.
	IOException(Throwable cause) Constructs an IOException with the specified cause and a detail message of (cause==null ? null : cause.toString()) (which typically contains the class and detail message of cause).

Inherited Method Summary

From class java.lang.Throwable

synchronized final void	addSuppressed(Throwable exception) Appends the specified exception to the exceptions that were suppressed in order to deliver this exception.
synchronized Throwable	fillInStackTrace() Fills in the execution stack trace.
synchronized Throwable	getCause() Returns the cause of this throwable or null if the cause is nonexistent or unknown.
String	getLocalizedMessage() Creates a localized description of this throwable.
String	getMessage() Returns the detail message string of this throwable.
StackTraceElement[]	getStackTrace() Provides programmatic access to the stack trace information printed by printStackTrace().
synchronized final Throwable[]	getSuppressed() Returns an array containing all of the exceptions that were suppressed, typically by the try-with-resources statement, in order to deliver this exception.
synchronized Throwable	initCause(Throwable cause) Initializes the cause of this throwable to the specified value.
void	printStackTrace() Prints this throwable and its backtrace to the standard error stream.
void	printStackTrace(PrintWriter s) Prints this throwable and its backtrace to the specified print writer.
void	printStackTrace(PrintStream s) Prints this throwable and its backtrace to the specified print stream.
void	setStackTrace(StackTraceElement[] stackTrace) Sets the stack trace elements that will be returned by getStackTrace() and printed by printStackTrace() and related methods.
String	toString() Returns a short description of this throwable.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Constructors

public IOException ()

Constructs an IOException with null as its error detail message.

public IOException (String message)

Constructs an IOException with the specified detail message.

Parameters

message	The detail message (which is saved for later retrieval by the Throwable.getMessage() method)

public IOException (String message, Throwable cause)

Constructs an IOException with the specified detail message and cause.

Note that the detail message associated with cause is not automatically incorporated into this exception's detail message.

Parameters

message	The detail message (which is saved for later retrieval by the Throwable.getMessage() method)
cause	The cause (which is saved for later retrieval by the Throwable.getCause() method). (A null value is permitted, and indicates that the cause is nonexistent or unknown.)

public IOException (Throwable cause)

Constructs an IOException with the specified cause and a detail message of (cause==null ? null : cause.toString()) (which typically contains the class and detail message of cause). This constructor is useful for IO exceptions that are little more than wrappers for other throwables.

Parameters

cause	The cause (which is saved for later retrieval by the Throwable.getCause() method). (A null value is permitted, and indicates that the cause is nonexistent or unknown.)