JavaTM 2 Platform
Std. Ed. v1.4.0

java.sql
Interface SQLInput


public interface SQLInput

An input stream that contains a stream of values representing an instance of an SQL structured type or an SQL distinct type. This interface, used only for custom mapping, is used by the driver behind the scenes, and a programmer never directly invokes SQLInput methods. The reader methods (readLong, readBytes, and so on) provide a way to read the values in an SQLInput object. The method wasNull is used to determine whether the the last value read was SQL NULL.

When the method getObject is called with an object of a class implementing the interface SQLData, the JDBC driver calls the method SQLData.getSQLType to determine the SQL type of the user-defined type (UDT) being custom mapped. The driver creates an instance of SQLInput, populating it with the attributes of the UDT. The driver then passes the input stream to the method SQLData.readSQL, which in turn calls the SQLInput reader methods in its implementation for reading the attributes from the input stream.

Since:
1.2

Method Summary
 Array readArray()
          Reads an SQL ARRAY value from the stream and returns it as an Array object in the Java programming language.
 InputStream readAsciiStream()
          Reads the next attribute in the stream and returns it as a stream of ASCII characters.
 BigDecimal readBigDecimal()
          Reads the next attribute in the stream and returns it as a java.math.BigDecimal object in the Java programming language.
 InputStream readBinaryStream()
          Reads the next attribute in the stream and returns it as a stream of uninterpreted bytes.
 Blob readBlob()
          Reads an SQL BLOB value from the stream and returns it as a Blob object in the Java programming language.
 boolean readBoolean()
          Reads the next attribute in the stream and returns it as a boolean in the Java programming language.
 byte readByte()
          Reads the next attribute in the stream and returns it as a byte in the Java programming language.
 byte[] readBytes()
          Reads the next attribute in the stream and returns it as an array of bytes in the Java programming language.
 Reader readCharacterStream()
          Reads the next attribute in the stream and returns it as a stream of Unicode characters.
 Clob readClob()
          Reads an SQL CLOB value from the stream and returns it as a Clob object in the Java programming language.
 Date readDate()
          Reads the next attribute in the stream and returns it as a java.sql.Date object.
 double readDouble()
          Reads the next attribute in the stream and returns it as a double in the Java programming language.
 float readFloat()
          Reads the next attribute in the stream and returns it as a float in the Java programming language.
 int readInt()
          Reads the next attribute in the stream and returns it as an int in the Java programming language.
 long readLong()
          Reads the next attribute in the stream and returns it as a long in the Java programming language.
 Object readObject()
          Reads the datum at the head of the stream and returns it as an Object in the Java programming language.
 Ref readRef()
          Reads an SQL REF value from the stream and returns it as a Ref object in the Java programming language.
 short readShort()
          Reads the next attribute in the stream and returns it as a short in the Java programming language.
 String readString()
          Reads the next attribute in the stream and returns it as a String in the Java programming language.
 Time readTime()
          Reads the next attribute in the stream and returns it as a java.sql.Time object.
 Timestamp readTimestamp()
          Reads the next attribute in the stream and returns it as a java.sql.Timestamp object.
 URL readURL()
          Reads an SQL DATALINK value from the stream and returns it as a java.net.URL object in the Java programming language.
 boolean wasNull()
          Retrieves whether the last value read was SQL NULL.
 

Method Detail

readString

public String readString()
                  throws SQLException
Reads the next attribute in the stream and returns it as a String in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readBoolean

public boolean readBoolean()
                    throws SQLException
Reads the next attribute in the stream and returns it as a boolean in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns false
Throws:
SQLException - if a database access error occurs

readByte

public byte readByte()
              throws SQLException
Reads the next attribute in the stream and returns it as a byte in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns 0
Throws:
SQLException - if a database access error occurs

readShort

public short readShort()
                throws SQLException
Reads the next attribute in the stream and returns it as a short in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns 0
Throws:
SQLException - if a database access error occurs

readInt

public int readInt()
            throws SQLException
Reads the next attribute in the stream and returns it as an int in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns 0
Throws:
SQLException - if a database access error occurs

readLong

public long readLong()
              throws SQLException
Reads the next attribute in the stream and returns it as a long in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns 0
Throws:
SQLException - if a database access error occurs

readFloat

public float readFloat()
                throws SQLException
Reads the next attribute in the stream and returns it as a float in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns 0
Throws:
SQLException - if a database access error occurs

readDouble

public double readDouble()
                  throws SQLException
Reads the next attribute in the stream and returns it as a double in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns 0
Throws:
SQLException - if a database access error occurs

readBigDecimal

public BigDecimal readBigDecimal()
                          throws SQLException
Reads the next attribute in the stream and returns it as a java.math.BigDecimal object in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readBytes

public byte[] readBytes()
                 throws SQLException
Reads the next attribute in the stream and returns it as an array of bytes in the Java programming language.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readDate

public Date readDate()
              throws SQLException
Reads the next attribute in the stream and returns it as a java.sql.Date object.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readTime

public Time readTime()
              throws SQLException
Reads the next attribute in the stream and returns it as a java.sql.Time object.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readTimestamp

public Timestamp readTimestamp()
                        throws SQLException
Reads the next attribute in the stream and returns it as a java.sql.Timestamp object.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readCharacterStream

public Reader readCharacterStream()
                           throws SQLException
Reads the next attribute in the stream and returns it as a stream of Unicode characters.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readAsciiStream

public InputStream readAsciiStream()
                            throws SQLException
Reads the next attribute in the stream and returns it as a stream of ASCII characters.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readBinaryStream

public InputStream readBinaryStream()
                             throws SQLException
Reads the next attribute in the stream and returns it as a stream of uninterpreted bytes.

Returns:
the attribute; if the value is SQL NULL, returns null
Throws:
SQLException - if a database access error occurs

readObject

public Object readObject()
                  throws SQLException
Reads the datum at the head of the stream and returns it as an Object in the Java programming language. The actual type of the object returned is determined by the default type mapping, and any customizations present in this stream's type map.

A type map is registered with the stream by the JDBC driver before the stream is passed to the application.

When the datum at the head of the stream is an SQL NULL, the method returns null. If the datum is an SQL structured or distinct type, it determines the SQL type of the datum at the head of the stream. If the stream's type map has an entry for that SQL type, the driver constructs an object of the appropriate class and calls the method SQLData.readSQL on that object, which reads additional data from the stream, using the protocol described for that method.

Returns:
the datum at the head of the stream as an Object in the Java programming language;null if the datum is SQL NULL
Throws:
SQLException - if a database access error occurs

readRef

public Ref readRef()
            throws SQLException
Reads an SQL REF value from the stream and returns it as a Ref object in the Java programming language.

Returns:
a Ref object representing the SQL REF value at the head of the stream; null if the value read is SQL NULL
Throws:
SQLException - if a database access error occurs

readBlob

public Blob readBlob()
              throws SQLException
Reads an SQL BLOB value from the stream and returns it as a Blob object in the Java programming language.

Returns:
a Blob object representing data of the SQL BLOB value at the head of the stream; null if the value read is SQL NULL
Throws:
SQLException - if a database access error occurs

readClob

public Clob readClob()
              throws SQLException
Reads an SQL CLOB value from the stream and returns it as a Clob object in the Java programming language.

Returns:
a Clob object representing data of the SQL CLOB value at the head of the stream; null if the value read is SQL NULL
Throws:
SQLException - if a database access error occurs

readArray

public Array readArray()
                throws SQLException
Reads an SQL ARRAY value from the stream and returns it as an Array object in the Java programming language.

Returns:
an Array object representing data of the SQL ARRAY value at the head of the stream; null if the value read is SQL NULL
Throws:
SQLException - if a database access error occurs

wasNull

public boolean wasNull()
                throws SQLException
Retrieves whether the last value read was SQL NULL.

Returns:
true if the most recently read SQL value was SQL NULL; false otherwise
Throws:
SQLException - if a database access error occurs

readURL

public URL readURL()
            throws SQLException
Reads an SQL DATALINK value from the stream and returns it as a java.net.URL object in the Java programming language.

Returns:
a java.net.URL object.
Throws:
SQLException - if a database access error occurs, or if a URL is malformed
Since:
1.4

JavaTM 2 Platform
Std. Ed. v1.4.0

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