Class MemoryClob

java.lang.Object
org.apache.cayenne.util.MemoryClob
All Implemented Interfaces:
Clob

public class MemoryClob
extends Object
implements Clob
A Clob implementation that stores contents in memory.

This implementation is based on jdbcClob from HSQLDB (copyright HSQL Development Group).

Since:
1.2
  • Constructor Summary

    Constructors
    Constructor Description
    MemoryClob​(String data)
    Constructs a new jdbcClob object wrapping the given character sequence.
  • Method Summary

    Modifier and Type Method Description
    void free()  
    InputStream getAsciiStream()
    Retrieves the CLOB value designated by this Clob object as an ascii stream.
    Reader getCharacterStream()
    Retrieves the CLOB value designated by this Clob object as a java.io.Reader object (or as a stream of characters).
    Reader getCharacterStream​(long pos, long length)  
    String getSubString​(long pos, int length)
    Retrieves a copy of the specified substring in the CLOB value designated by this Clob object.
    long length()
    Retrieves the number of characters in the CLOB value designated by this Clob object.
    long position​(String searchstr, long start)
    Retrieves the character position at which the specified substring searchstr appears in the SQL CLOB value represented by this Clob object.
    long position​(Clob searchstr, long start)
    Retrieves the character position at which the specified Clob object searchstr appears in this Clob object.
    OutputStream setAsciiStream​(long pos)
    Retrieves a stream to be used to write Ascii characters to the CLOB value that this Clob object represents, starting at position pos.
    Writer setCharacterStream​(long pos)
    Retrieves a stream to be used to write a stream of Unicode characters to the CLOB value that this Clob object represents, at position pos.
    int setString​(long pos, String str)
    Writes the given Java String to the CLOB value that this Clob object designates at the position pos.
    int setString​(long pos, String str, int offset, int len)
    Writes len characters of str, starting at character offset, to the CLOB value that this Clob represents.
    void truncate​(long len)
    Truncates the CLOB value that this Clob designates to have a length of len characters.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • MemoryClob

      public MemoryClob​(String data)
      Constructs a new jdbcClob object wrapping the given character sequence.

      This constructor is used internally to retrieve result set values as Clob objects, yet it must be public to allow access from other packages. As such (in the interest of efficiency) this object maintains a reference to the given String object rather than making a copy and so it is gently suggested (in the interest of effective memory management) that extenal clients using this constructor either take pause to consider the implications or at least take care to provide a String object whose internal character buffer is not much larger than required to represent the value.

      Parameters:
      data - the character sequence representing the Clob value
      Throws:
      CayenneRuntimeException - if the argument is null
  • Method Details

    • length

      public long length() throws SQLException
      Retrieves the number of characters in the CLOB value designated by this Clob object.
      Specified by:
      length in interface Clob
      Returns:
      length of the CLOB in characters
      Throws:
      SQLException - if there is an error accessing the length of the CLOB value
    • getSubString

      public String getSubString​(long pos, int length) throws SQLException
      Retrieves a copy of the specified substring in the CLOB value designated by this Clob object. The substring begins at position pos and has up to length consecutive characters.
      Specified by:
      getSubString in interface Clob
      Throws:
      SQLException
    • getCharacterStream

      public Reader getCharacterStream() throws SQLException
      Retrieves the CLOB value designated by this Clob object as a java.io.Reader object (or as a stream of characters).
      Specified by:
      getCharacterStream in interface Clob
      Returns:
      a java.io.Reader object containing the CLOB data
      Throws:
      SQLException - if there is an error accessing the CLOB value
    • getAsciiStream

      public InputStream getAsciiStream() throws SQLException
      Retrieves the CLOB value designated by this Clob object as an ascii stream.
      Specified by:
      getAsciiStream in interface Clob
      Returns:
      a java.io.InputStream object containing the CLOB data
      Throws:
      SQLException - if there is an error accessing the CLOB value
    • position

      public long position​(String searchstr, long start) throws SQLException
      Retrieves the character position at which the specified substring searchstr appears in the SQL CLOB value represented by this Clob object. The search begins at position start.
      Specified by:
      position in interface Clob
      Parameters:
      searchstr - the substring for which to search
      start - the position at which to begin searching; the first position is 1
      Returns:
      the position at which the substring appears or -1 if it is not present; the first position is 1
      Throws:
      SQLException - if there is an error accessing the CLOB value
    • position

      public long position​(Clob searchstr, long start) throws SQLException
      Retrieves the character position at which the specified Clob object searchstr appears in this Clob object. The search begins at position start.
      Specified by:
      position in interface Clob
      Parameters:
      searchstr - the Clob object for which to search
      start - the position at which to begin searching; the first position is 1
      Returns:
      the position at which the Clob object appears or -1 if it is not present; the first position is 1
      Throws:
      SQLException - if there is an error accessing the CLOB value
    • setString

      public int setString​(long pos, String str) throws SQLException
      Writes the given Java String to the CLOB value that this Clob object designates at the position pos. Calling this method always throws an SQLException.
      Specified by:
      setString in interface Clob
      Throws:
      SQLException
    • setString

      public int setString​(long pos, String str, int offset, int len) throws SQLException
      Writes len characters of str, starting at character offset, to the CLOB value that this Clob represents. Calling this method always throws an SQLException.
      Specified by:
      setString in interface Clob
      Throws:
      SQLException
    • setAsciiStream

      public OutputStream setAsciiStream​(long pos) throws SQLException
      Retrieves a stream to be used to write Ascii characters to the CLOB value that this Clob object represents, starting at position pos.

      Calling this method always throws an SQLException.

      Specified by:
      setAsciiStream in interface Clob
      Throws:
      SQLException
    • setCharacterStream

      public Writer setCharacterStream​(long pos) throws SQLException
      Retrieves a stream to be used to write a stream of Unicode characters to the CLOB value that this Clob object represents, at position pos.

      Calling this method always throws an SQLException.

      Specified by:
      setCharacterStream in interface Clob
      Throws:
      SQLException
    • truncate

      public void truncate​(long len) throws SQLException
      Truncates the CLOB value that this Clob designates to have a length of len characters.

      Specified by:
      truncate in interface Clob
      Throws:
      SQLException
    • free

      public void free() throws SQLException
      Specified by:
      free in interface Clob
      Throws:
      SQLException
      Since:
      3.0
    • getCharacterStream

      public Reader getCharacterStream​(long pos, long length) throws SQLException
      Specified by:
      getCharacterStream in interface Clob
      Throws:
      SQLException
      Since:
      3.0