Package org.apache.sis.util.collection

Class BackingStoreException

  • All Implemented Interfaces:
    Serializable
    public class BackingStoreException
extends RuntimeException
    Thrown to indicate that an operation could not complete because of a failure in the backing store (a file or a database). This exception is thrown by implementations of API (collection, streams, etc. that are not allowed to throw checked exceptions. This exception usually has an IOException or a SQLException as its cause.

    This method provides a unwrap­Or­Rethrow(Class) convenience method which can be used for re-throwing the cause as in the example below. This allows client code to behave as if a Collection interface was allowed to declare checked exceptions.

    void myMethod() throws IOException {
    Collection c = ...;
    try {
        c.doSomeStuff();
    } catch (BackingStoreException e) {
        throw e.unwrapOrRethrow(IOException.class);
    }
}
    Relationship with java​.io​.Unchecked­IOException
    JDK8 provides a Unchecked­IOException which partially overlaps the purpose of this Backing­Store­Exception. While Apache SIS still uses Backing­Store­Exception as a general mechanism for any kind of checked exceptions, client code would be well advised to catch both kind of exceptions for robustness.
    Since:
    0.3
    See Also:
    Serialized Form

    Defined in the sis-utility module

    • Constructor Detail

      • BackingStoreException

        public BackingStoreException()
        Constructs a new exception with no detail message.

      • BackingStoreException

        public BackingStoreException​(String message)
        Constructs a new exception with the specified detail message.
        Parameters:
        message - the detail message, saved for later retrieval by the Throwable​.get­Message() method.

      • BackingStoreException

        public BackingStoreException​(Throwable cause)
        Constructs a new exception with the specified cause.
        Parameters:
        cause - the cause, saved for later retrieval by the Throwable​.get­Cause() method.

      • BackingStoreException

        public BackingStoreException​(String message,
                             Throwable cause)
        Constructs a new exception with the specified detail message and cause.
        Parameters:
        message - the detail message, saved for later retrieval by the Throwable​.get­Message() method.
        cause - the cause, saved for later retrieval by the Throwable​.get­Cause() method.

    • Method Detail

      • unwrapOrRethrow

        public <E extends Exception> E unwrapOrRethrow​(Class<E> type)
                                        throws RuntimeException,
                                               BackingStoreException
        Returns the underlying cause as an exception of the given type, or re-throw the exception. More specifically, this method makes the following choices:
        • If the cause is an instance of the given type, returns the cause.
        • Otherwise if the cause is an instance of Runtime­Exception, throws that exception.
        • Otherwise re-throws this.
        This method should be used as in the example below: 
        void myMethod() throws IOException {
    Collection c = ...;
    try {
        c.doSomeStuff();
    } catch (BackingStoreException e) {
        throw e.unwrapOrRethrow(IOException.class);
    }
}
        Type Parameters:
        E - the type of the exception to unwrap.
        Parameters:
        type - the type of the exception to unwrap.
        Returns:
        the cause as an exception of the given type (never null).
        Throws:
        Runtime­Exception - if the cause is an instance of Runtime­Exception, in which case that instance is re-thrown.
        Backing­Store­Exception - if the cause is neither the given type or an instance of Runtime­Exception, in which case this exception is re-thrown.