Class DbInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable

    public class DbInputStream
    extends AutoCloseInputStream
    This class represents an input stream backed by a database. The database objects are only acquired when reading from the stream, and stay open until the stream is closed, fully read, or garbage collected.

    This class does not support mark/reset. It is always to be wrapped using a BufferedInputStream.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int available()
      Invokes the delegate's available() method.
      void close()
      Closes the underlying input stream and replaces the reference to it with a ClosedInputStream instance.
      void mark​(int readlimit)
      This method does nothing.
      boolean markSupported()
      Check whether mark and reset are supported.
      int read()
      Invokes the delegate's read() method.
      int read​(byte[] b)
      Invokes the delegate's read(byte[]) method.
      int read​(byte[] b, int off, int len)
      Invokes the delegate's read(byte[], int, int) method.
      void reset()
      This method does nothing.
      long skip​(long n)
      Invokes the delegate's skip(long) method.
      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Method Detail

      • read

        public int read()
                 throws java.io.IOException
        Invokes the delegate's read() method. When the stream is consumed, the database objects held by the instance are closed.
        Overrides:
        read in class ProxyInputStream
        Returns:
        the byte read or -1 if the end of stream
        Throws:
        java.io.IOException - if an I/O error occurs.
      • read

        public int read​(byte[] b)
                 throws java.io.IOException
        Invokes the delegate's read(byte[]) method. When the stream is consumed, the database objects held by the instance are closed.
        Overrides:
        read in class ProxyInputStream
        Parameters:
        b - the buffer to read the bytes into
        Returns:
        the number of bytes read or EOF if the end of stream
        Throws:
        java.io.IOException - if an I/O error occurs.
      • read

        public int read​(byte[] b,
                        int off,
                        int len)
                 throws java.io.IOException
        Invokes the delegate's read(byte[], int, int) method. When the stream is consumed, the database objects held by the instance are closed.
        Overrides:
        read in class ProxyInputStream
        Parameters:
        b - the buffer to read the bytes into
        off - The start offset
        len - The number of bytes to read
        Returns:
        the number of bytes read or -1 if the end of stream
        Throws:
        java.io.IOException - if an I/O error occurs.
      • close

        public void close()
                   throws java.io.IOException
        Closes the underlying input stream and replaces the reference to it with a ClosedInputStream instance.

        This method is automatically called by the read methods when the end of input has been reached.

        Note that it is safe to call this method any number of times. The original underlying input stream is closed and discarded only once when this method is first called. When the stream is consumed, the database objects held by the instance are closed.

        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class AutoCloseInputStream
        Throws:
        java.io.IOException - if the underlying input stream can not be closed
      • skip

        public long skip​(long n)
                  throws java.io.IOException
        Invokes the delegate's skip(long) method.
        Overrides:
        skip in class ProxyInputStream
        Parameters:
        n - the number of bytes to skip
        Returns:
        the actual number of bytes skipped
        Throws:
        java.io.IOException - if an I/O error occurs.
      • available

        public int available()
                      throws java.io.IOException
        Invokes the delegate's available() method.
        Overrides:
        available in class ProxyInputStream
        Returns:
        the number of available bytes
        Throws:
        java.io.IOException - if an I/O error occurs.
      • mark

        public void mark​(int readlimit)
        This method does nothing.
        Overrides:
        mark in class ProxyInputStream
        Parameters:
        readlimit - read ahead limit
      • reset

        public void reset()
                   throws java.io.IOException
        This method does nothing.
        Overrides:
        reset in class ProxyInputStream
        Throws:
        java.io.IOException - if an I/O error occurs.
      • markSupported

        public boolean markSupported()
        Check whether mark and reset are supported.
        Overrides:
        markSupported in class ProxyInputStream
        Returns:
        false