Java Module java.sql Package java.sql Interface Clob（JDK11）

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All Known Subinterfaces:

NClob

All Known Implementing Classes:

SerialClob
```
public interface Clob
```
The mapping in the Java™ programming language for the SQL CLOB type. An SQL CLOB is a built-in type that stores a Character Large Object as a column value in a row of a database table. By default drivers implement a Clob object using an SQL locator(CLOB), which means that a Clob object contains a logical pointer to the SQL CLOB data rather than the data itself. A Clob object is valid for the duration of the transaction in which it was created.
The Clob interface provides methods for getting the length of an SQL CLOB (Character Large Object) value, for materializing a CLOB value on the client, and for searching for a substring or CLOB object within a CLOB value. Methods in the interfaces ResultSet, CallableStatement, and PreparedStatement, such as getClob and setClob allow a programmer to access an SQL CLOB value. In addition, this interface has methods for updating a CLOB value.

All methods on the Clob interface must be fully implemented if the JDBC driver supports the data type.

Since:

1.2

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`free()`	This method releases the resources that the `Clob` object holds.
`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)`	Returns a `Reader` object that contains a partial `Clob` value, starting with the character specified by pos, which is length characters in 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.

- Method Detail
  - length
```
long length()
     throws SQLException
```
    Retrieves the number of characters in the CLOB value designated by this Clob object.
    
    Returns:
    
    length of the CLOB in characters
    
    Throws:
    
    SQLException - if there is an error accessing the length of the CLOB value
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.2
  - getSubString
```
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.
    
    Parameters:
    
    pos - the first character of the substring to be extracted. The first character is at position 1.
    
    length - the number of consecutive characters to be copied; the value for length must be 0 or greater
    
    Returns:
    
    a String that is the specified substring in the CLOB value designated by this Clob object
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value; if pos is less than 1 or length is less than 0
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.2
  - getCharacterStream
```
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).
    
    Returns:
    
    a java.io.Reader object containing the CLOB data
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.2
    
    See Also:
    
    setCharacterStream(long)
  - getAsciiStream
```
InputStream getAsciiStream()
                    throws SQLException
```
    Retrieves the CLOB value designated by this Clob object as an ascii stream.
    
    Returns:
    
    a java.io.InputStream object containing the CLOB data
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.2
    
    See Also:
    
    setAsciiStream(long)
  - position
```
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.
    
    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 or if pos is less than 1
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.2
  - position
```
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.
    
    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 or if start is less than 1
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.2
  - setString
```
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. The string will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing the given string, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater than the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw an SQLException while other drivers may support this operation.
    
    Parameters:
    
    pos - the position at which to start writing to the CLOB value that this Clob object represents; the first position is 1.
    
    str - the string to be written to the CLOB value that this Clob designates
    
    Returns:
    
    the number of characters written
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value or if pos is less than 1
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.4
  - setString
```
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. The string will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing the given string, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater than the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw an SQLException while other drivers may support this operation.
    
    Parameters:
    
    pos - the position at which to start writing to this CLOB object; The first position is 1
    
    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
    
    len - the number of characters to be written
    
    Returns:
    
    the number of characters written
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value or if pos is less than 1
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.4
  - setAsciiStream
```
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. Characters written to the stream will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing characters to the stream, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater than the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw an SQLException while other drivers may support this operation.
    
    Parameters:
    
    pos - the position at which to start writing to this CLOB object; The first position is 1
    
    Returns:
    
    the stream to which ASCII encoded characters can be written
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value or if pos is less than 1
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.4
    
    See Also:
    
    getAsciiStream()
  - setCharacterStream
```
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. Characters written to the stream will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing characters to the stream, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater than the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw an SQLException while other drivers may support this operation.
    
    Parameters:
    
    pos - the position at which to start writing to the CLOB value; The first position is 1
    
    Returns:
    
    a stream to which Unicode encoded characters can be written
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value or if pos is less than 1
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.4
    
    See Also:
    
    getCharacterStream()
  - truncate
```
void truncate(long len)
       throws SQLException
```
    Truncates the CLOB value that this Clob designates to have a length of len characters.
    Note: If the value specified for pos is greater than the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw an SQLException while other drivers may support this operation.
    
    Parameters:
    
    len - the length, in characters, to which the CLOB value should be truncated
    
    Throws:
    
    SQLException - if there is an error accessing the CLOB value or if len is less than 0
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.4
  - free
```
void free()
   throws SQLException
```
    This method releases the resources that the Clob object holds. The object is invalid once the free method is called.
    After free has been called, any attempt to invoke a method other than free will result in a SQLException being thrown. If free is called multiple times, the subsequent calls to free are treated as a no-op.
    
    Throws:
    
    SQLException - if an error occurs releasing the Clob's resources
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.6
  - getCharacterStream
```
Reader getCharacterStream(long pos,
                          long length)
                   throws SQLException
```
    Returns a Reader object that contains a partial Clob value, starting with the character specified by pos, which is length characters in length.
    
    Parameters:
    
    pos - the offset to the first character of the partial value to be retrieved. The first character in the Clob is at position 1.
    
    length - the length in characters of the partial value to be retrieved.
    
    Returns:
    
    Reader through which the partial Clob value can be read.
    
    Throws:
    
    SQLException - if pos is less than 1; or if pos is greater than the number of characters in the Clob; or if pos + length is greater than the number of characters in the Clob
    
    SQLFeatureNotSupportedException - if the JDBC driver does not support this method
    
    Since:
    
    1.6

Java Module java.sql Package java.sql Interface Clob（JDK11）

Interface Clob

Method Summary

Method Detail

length

getSubString

getCharacterStream

getAsciiStream

position

position

setString

setString

setAsciiStream

setCharacterStream

truncate

free

getCharacterStream