7.1.7 Sending Very Large IN Parameters

The methods setBytes and setString are capable of sending unlimited amounts of data. Sometimes, however, programmers prefer to pass in large blobs of data in smaller chunks. This can be accomplished by setting an IN parameter to a Java input stream. When the statement is executed, the JDBC driver will make repeated calls to this input stream, reading its contents and transmitting those contents as the actual parameter data.

The JDBC 1.0 API provides two methods for setting IN parameters to input streams: setBinaryStream for streams containing uninterpreted bytes and setAsciiStream for streams containing ASCII characters. A third method, set-UnicodeStream for streams containing Unicode characters, has been deprecated; the new JDBC 2.0 core API method setCharacterStream should be used in its place. These stream methods take one more argument than the other setter methods because the total length of the stream must be specified. This is necessary because some database systems need to know the total transfer size before any data is sent.
The following code illustrates using a stream to send the contents of a file as an IN parameter.

java.io.File file = new java.io.File("/tmp/data");
int fileLength = file.length();
java.io.InputStream fin = new java.io.FileInputStream(file);
java.sql.PreparedStatement pstmt = con.prepareStatement(
"UPDATE Table5 SET stuff = ? WHERE index = 4");
pstmt.setBinaryStream (1, fin, fileLength);
pstmt.executeUpdate();

When the statement executes, the input stream fin will get called repeatedly to deliver up its data.
Another way to send large IN parameters to the database is to use SQL99 types like BLOB and CLOB. This is different from using streams in that BLOB and CLOB values are originally retrieved from the database, where they were created as SQL types. Using streams makes it possible to send the contents of a file written in the Java programming language to the database.