Module java.sql.rowset
Package javax.sql.rowset.serial

# Class SerialClob

java.lang.Object
javax.sql.rowset.serial.SerialClob

All Implemented Interfaces:
  `Serializable`, `Cloneable`, `Clob`

public class SerialClob extends Object implements Clob, Serializable, Cloneable
A serialized mapping in the Java programming language of an SQL `CLOB` value.

The `SerialClob` class provides a constructor for creating an instance from a `Clob` object. Note that the `Clob` object should have brought the SQL `CLOB` value's data over to the client before a `SerialClob` object is constructed from it. The data of an SQL `CLOB` value can be materialized on the client as a stream of Unicode characters.

`SerialClob` methods make it possible to get a substring from a `SerialClob` object or to locate the start of a pattern of characters.

## Thread safety

A SerialClob is not safe for use by multiple concurrent threads. If a SerialClob is to be used by more than one thread then access to the SerialClob should be controlled by appropriate synchronization.

Since:
  1.5
See Also:
  - Serialized Form

## Constructor Summary

Constructors
Constructor
Description
`SerialClob(char[] ch)`
Constructs a `SerialClob` object that is a serialized version of the given `char` array.
`SerialClob(Clob clob)`
Constructs a `SerialClob` object that is a serialized version of the given `Clob` object.

## Method Summary

Modifier and Type
Method
Description
`Object`
`clone()`
Returns a clone of this `SerialClob`.
`boolean`
`equals(Object obj)`
Compares this SerialClob to the specified object.
`void`
`free()`
This method frees the `SerialClob` object and releases the resources that it holds.
`InputStream`
`getAsciiStream()`
Retrieves the `CLOB` value designated by this `SerialClob` object as an ascii stream.
`Reader`
`getCharacterStream()`
Returns this `SerialClob` object's data as a stream of Unicode characters.
`Reader`
`getCharacterStream(long pos, long length)`
Returns a `Reader` object that contains a partial `SerialClob` value, starting with the character specified by pos, which is length characters in length.
`String`
`getSubString(long pos, int length)`
Returns a copy of the substring contained in this `SerialClob` object, starting at the given position and continuing for the specified number or characters.
`int`
`hashCode()`
Returns a hash code for this `SerialClob`.
`long`
`length()`
Retrieves the number of characters in this `SerialClob` object's array of characters.
`long`
`position(String searchStr, long start)`
Returns the position in this `SerialClob` object where the given `String` object begins, starting the search at the specified position.
`long`
`position(Clob searchStr, long start)`
Returns the position in this `SerialClob` object where the given `Clob` signature begins, starting the search at the specified position.
`OutputStream`
`setAsciiStream(long pos)`
Retrieves a stream to be used to write Ascii characters to the `CLOB` value that this `SerialClob` 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 `SerialClob` object represents, at position `pos`.
`int`
`setString(long pos, String str)`
Writes the given Java `String` to the `CLOB` value that this `SerialClob` object represents, at the position `pos`.
`int`
`setString(long pos, String str, int offset, int length)`
Writes `len` characters of `str`, starting at character `offset`, to the `CLOB` value that this `Clob` represents.
`void`
`truncate(long length)`
Truncates the `CLOB` value that this `SerialClob` object represents so that it has a length of `len` characters.

### Methods declared in class java.lang.Object

`finalize, getClass, notify, notifyAll, toString, wait, wait, wait`

## Constructor Details

### SerialClob

public SerialClob(char[] ch) throws SerialException, SQLException
Constructs a `SerialClob` object that is a serialized version of the given `char` array.

The new `SerialClob` object is initialized with the data from the `char` array, thus allowing disconnected `RowSet` objects to establish a serialized `Clob` object without touching the data source.

Parameters:
  `ch` - the char array representing the `Clob` object to be serialized
Throws:
  `SerialException` - if an error occurs during serialization
  `SQLException` - if a SQL error occurs

### SerialClob

public SerialClob(Clob clob) throws SerialException, SQLException
Constructs a `SerialClob` object that is a serialized version of the given `Clob` object.

The new `SerialClob` object is initialized with the data from the `Clob` object; therefore, the `Clob` object should have previously brought the SQL `CLOB` value's data over to the client from the database. Otherwise, the new `SerialClob` object object will contain no data.

Note: The `Clob` object supplied to this constructor must return non-null for both the `Clob.getCharacterStream()` and `Clob.getAsciiStream` methods. This `SerialClob` constructor cannot serialize a `Clob` object in this instance and will throw an `SQLException` object.

Parameters:
  `clob` - the `Clob` object from which this `SerialClob` object is to be constructed; cannot be null
Throws:
  `SerialException` - if an error occurs during serialization
  `SQLException` - if a SQL error occurs in capturing the CLOB; if the `Clob` object is a null; or if either of the `Clob.getCharacterStream()` and `Clob.getAsciiStream()` methods on the `Clob` returns a null
See Also:
  - `Clob`

## Method Details

### length

public long length() throws SerialException
Retrieves the number of characters in this `SerialClob` object's array of characters.

Specified by:
  `length` in interface `Clob`
Returns:
  a `long` indicating the length in characters of this `SerialClob` object's array of character
Throws:
  `SerialException` - if an error occurs; if `free` had previously been called on this object

### getCharacterStream

public Reader getCharacterStream() throws SerialException
Returns this `SerialClob` object's data as a stream of Unicode characters. Unlike the related method, `getAsciiStream`, a stream is produced regardless of whether the `SerialClob` object was created with a `Clob` object or a `char` array.

Specified by:
  `getCharacterStream` in interface `Clob`
Returns:
  a `java.io.Reader` object containing this `SerialClob` object's data
Throws:
  `SerialException` - if an error occurs; if `free` had previously been called on this object
See Also:
  - `Clob.setCharacterStream(long)`

### getAsciiStream

public InputStream getAsciiStream() throws SerialException, SQLException
Retrieves the `CLOB` value designated by this `SerialClob` object as an ascii stream. This method forwards the `getAsciiStream` call to the underlying `Clob` object in the event that this `SerialClob` object is instantiated with a `Clob` object. If this `SerialClob` object is instantiated with a `char` array, a `SerialException` object is thrown.

Specified by:
  `getAsciiStream` in interface `Clob`
Returns:
  a `java.io.InputStream` object containing this `SerialClob` object's data
Throws:
  `SerialException` - if this `SerialClob` object was not instantiated with a `Clob` object; if `free` had previously been called on this object
  `SQLException` - if there is an error accessing the `CLOB` value represented by the `Clob` object that was used to create this `SerialClob` object
See Also:
  - `Clob.setAsciiStream(long)`

### getSubString

public String getSubString(long pos, int length) throws SerialException
Returns a copy of the substring contained in this `SerialClob` object, starting at the given position and continuing for the specified number or characters.

Specified by:
  `getSubString` in interface `Clob`
Parameters:
  `pos` - the position of the first character in the substring to be copied; the first character of the `SerialClob` object is at position `1`; must not be less than `1`, and the sum of the starting position and the length of the substring must be less than the length of this `SerialClob` object
  `length` - the number of characters in the substring to be returned; must not be greater than the length of this `SerialClob` object, and the sum of the starting position and the length of the substring must be less than the length of this `SerialClob` object
Returns:
  a `String` object containing a substring of this `SerialClob` object beginning at the given position and containing the specified number of consecutive characters
Throws:
  `SerialException` - if either of the arguments is out of bounds; if `free` had previously been called on this object

### position

public long position(String searchStr, long start) throws SerialException, SQLException
Returns the position in this `SerialClob` object where the given `String` object begins, starting the search at the specified position. This method returns `-1` if the pattern is not found.

Specified by:
  `position` in interface `Clob`
Parameters:
  `searchStr` - the `String` object for which to search
  `start` - the position in this `SerialClob` object at which to start the search; the first position is `1`; must not be less than `1` nor greater than the length of this `SerialClob` object
Returns:
  the position at which the given `String` object begins, starting the search at the specified position; `-1` if the given `String` object is not found or the starting position is out of bounds; position numbering for the return value starts at `1`
Throws:
  `SerialException` - if the `free` method had been previously called on this object
  `SQLException` - if there is an error accessing the Clob value from the database.

### position

public long position(Clob searchStr, long start) throws SerialException, SQLException
Returns the position in this `SerialClob` object where the given `Clob` signature begins, starting the search at the specified position. This method returns `-1` if the pattern is not found.

Specified by:
  `position` in interface `Clob`
Parameters:
  `searchStr` - the `Clob` object for which to search
  `start` - the position in this `SerialClob` object at which to begin the search; the first position is `1`; must not be less than `1` nor greater than the length of this `SerialClob` object
Returns:
  the position at which the given `Clob` object begins in this `SerialClob` object, at or after the specified starting position
Throws:
  `SerialException` - if an error occurs locating the Clob signature; if the `free` method had been previously called on this object
  `SQLException` - if there is an error accessing the Clob value from the database

### setString

public int setString(long pos, String str) throws SerialException
Writes the given Java `String` to the `CLOB` value that this `SerialClob` object represents, at the position `pos`.

Specified by:
  `setString` in interface `Clob`
Parameters:
  `pos` - the position at which to start writing to the `CLOB` value that this `SerialClob` object represents; the first position is `1`; must not be less than `1` nor greater than the length+1 of this `SerialClob` object
  `str` - the string to be written to the `CLOB` value that this `SerialClob` object represents
Returns:
  the number of characters written
Throws:
  `SerialException` - if there is an error accessing the `CLOB` value; if an invalid position is set; if the `free` method had been previously called on this object

### setString

public int setString(long pos, String str, int offset, int length) throws SerialException
Writes `len` characters of `str`, starting at character `offset`, to the `CLOB` value that this `Clob` represents.

Specified by:
  `setString` in interface `Clob`
Parameters:
  `pos` - the position at which to start writing to the `CLOB` value that this `SerialClob` object represents; the first position is `1`; must not be less than `1` nor greater than the length+1 of this `SerialClob` object
  `str` - the string to be written to the `CLOB` value that this `Clob` object represents
  `offset` - the offset into `str` to start reading the characters to be written
  `length` - the number of characters to be written
Returns:
  the number of characters written
Throws:
  `SerialException` - if there is an error accessing the `CLOB` value; if an invalid position is set; if an invalid offset value is set; or the combined values of the `length` and `offset` is greater than the length of `str`; if the `free` method had been previously called on this object

### setAsciiStream

public OutputStream setAsciiStream(long pos) throws SerialException, SQLException
Retrieves a stream to be used to write Ascii characters to the `CLOB` value that this `SerialClob` object represents, starting at position `pos`. This method forwards the `setAsciiStream()` call to the underlying `Clob` object in the event that this `SerialClob` object is instantiated with a `Clob` object. If this `SerialClob` object is instantiated with a `char` array, a `SerialException` object is thrown.

Specified by:
  `setAsciiStream` in interface `Clob`
Parameters:
  `pos` - the position at which to start writing to the `CLOB` object
Returns:
  the stream to which ASCII encoded characters can be written
Throws:
  `SerialException` - if SerialClob is not instantiated with a Clob object; if the `free` method had been previously called on this object
  `SQLException` - if there is an error accessing the `CLOB` value
See Also:
  - `getAsciiStream()`

### setCharacterStream

public Writer setCharacterStream(long pos) throws SerialException, SQLException
Retrieves a stream to be used to write a stream of Unicode characters to the `CLOB` value that this `SerialClob` object represents, at position `pos`. This method forwards the `setCharacterStream()` call to the underlying `Clob` object in the event that this `SerialClob` object is instantiated with a `Clob` object. If this `SerialClob` object is instantiated with a `char` array, a `SerialException` is thrown.

Specified by:
  `setCharacterStream` in interface `Clob`
Parameters:
  `pos` - the position at which to start writing to the `CLOB` value
Returns:
  a stream to which Unicode encoded characters can be written
Throws:
  `SerialException` - if the SerialClob is not instantiated with a Clob object; if the `free` method had been previously called on this object
  `SQLException` - if there is an error accessing the `CLOB` value
See Also:
  - `getCharacterStream()`

### truncate

public void truncate(long length) throws SerialException
Truncates the `CLOB` value that this `SerialClob` object represents so that it has a length of `len` characters.

Truncating a `SerialClob` object to length 0 has the effect of clearing its contents.

Specified by:
  `truncate` in interface `Clob`
Parameters:
  `length` - the length, in bytes, to which the `CLOB` value should be truncated
Throws:
  `SerialException` - if there is an error accessing the `CLOB` value; if the `free` method had been previously called on this object

### getCharacterStream

public Reader getCharacterStream(long pos, long length) throws SQLException
Returns a `Reader` object that contains a partial `SerialClob` value, starting with the character specified by pos, which is length characters in length.

Specified by:
  `getCharacterStream` in interface `Clob`
Parameters:
  `pos` - the offset to the first character of the partial value to be retrieved. The first character in the `SerialClob` is at position 1.
  `length` - the length in characters of the partial value to be retrieved.
Returns:
  `Reader` through which the partial `SerialClob` value can be read.
Throws:
  `SQLException` - if pos is less than 1 or if pos is greater than the number of characters in the `SerialClob` or if pos + length is greater than the number of characters in the `SerialClob`;
  `SerialException` - if the `free` method had been previously called on this object
Since:
  1.6

### free

public void free() throws SQLException
This method frees the `SerialClob` object and releases the resources that it holds. The object is invalid once the `free` method is called.

If `free` is called multiple times, the subsequent calls to `free` are treated as a no-op.

Specified by:
  `free` in interface `Clob`
Throws:
  `SQLException` - if an error occurs releasing the Clob's resources
Since:
  1.6

### equals

public boolean equals(Object obj)
Compares this SerialClob to the specified object. The result is `true` if and only if the argument is not `null` and is a `SerialClob` object that represents the same sequence of characters as this object.

Overrides:
  `equals` in class `Object`
Parameters:
  `obj` - The object to compare this `SerialClob` against
Returns:
  `true` if the given object represents a `SerialClob` equivalent to this SerialClob, `false` otherwise
See Also:
  - `Object.hashCode()`
  - `HashMap`

### hashCode

public int hashCode()
Returns a hash code for this `SerialClob`.

Overrides:
  `hashCode` in class `Object`
Returns:
  a hash code value for this object.
See Also:
  - `Object.equals(java.lang.Object)`
  - `System.identityHashCode(java.lang.Object)`

### clone

public Object clone()
Returns a clone of this `SerialClob`. The copy will contain a reference to a clone of the internal character array, not a reference to the original internal character array of this `SerialClob` object. The underlying `Clob` object will be set to null.

Overrides:
  `clone` in class `Object`
Returns:
  a clone of this SerialClob
See Also:
  - `Cloneable`