∟Inserting CLOB Values with setCharacterStream() Method
This section describes how to insert CLOB values with the PreparedStatement.setCharacterStream() method.
If you want to insert the entire content of a text file into a CLOB column, you should create a Reader object from this file,
and use the PreparedStatement.setCharacterStream() method to pass the text file content to the CLOB column through the Reader object.
There are 3 versions of the setCharacterStream() method, two of them were added as part of JDBC 4.0 (Java 1.6).
Your JDBC driver may not support them:
setCharacterStream(int parameterIndex, Reader reader) - The data will be read from the Reader stream as needed until end-of-file is reached.
This was added in JDBC 4.0 (Java 1.6).
setCharacterStream(int parameterIndex, Reader reader, int length) - The data will be read from the Reader stream as needed for "length" characters.
setCharacterStream(int parameterIndex, Reader reader, long length) - The data will be read from the Reader stream as needed for "length" characters.
This was added in JDBC 4.0 (Java 1.6).
To test those setCharacterStream() methods, wrote the following program:
/**
* OracleClobSetCharacterStream.java
* Copyright (c) 2007 by Dr. Herong Yang. All rights reserved.
*/
import java.io.*;
import java.sql.*;
public class OracleClobSetCharacterStream {
public static void main(String [] args) {
Connection con = null;
try {
oracle.jdbc.pool.OracleDataSource ds
= new oracle.jdbc.pool.OracleDataSource();
ds.setDriverType("thin");
ds.setServerName("localhost");
ds.setPortNumber(1521);
ds.setDatabaseName("XE");
ds.setUser("Herong");
ds.setPassword("TopSecret");
con = ds.getConnection();
// Deleting the record for re-testing
String subject = "Test of setCharacterStream() methods";
Statement sta = con.createStatement();
sta.executeUpdate("DELETE FROM Article WHERE Subject = '"
+subject+"'");
// Inserting CLOB value with a PreparedStatement
PreparedStatement ps = con.prepareStatement(
"INSERT INTO Article (ID, Subject, Body) VALUES (3,?,?)");
ps.setString(1, subject);
Reader bodyIn =
new FileReader("OracleClobSetCharacterStream.java");
// Test 1 - This will not work with JDBC 3.0 drivers
// ps.setCharacterStream(2, bodyIn);
// Test 2 - This will not work with JDBC 3.0 drivers
// File fileIn = new File("OracleClobSetCharacterStream.java");
// ps.setCharacterStream(2, bodyIn, fileIn.length());
// Test 3 - This works with JDBC 3.0 drivers
File fileIn = new File("OracleClobSetCharacterStream.java");
ps.setCharacterStream(2, bodyIn, (int) fileIn.length());
int count = ps.executeUpdate();
bodyIn.close();
ps.close();
// Retrieving CLOB value with getString()
sta = con.createStatement();
ResultSet res = sta.executeQuery("SELECT * FROM Article"
+" WHERE Subject = '"+subject+"'");
res.next();
System.out.println("The inserted record: ");
System.out.println(" Subject = "+res.getString("Subject"));
System.out.println(" Body = "
+res.getString("Body").substring(0,256));
res.close();
sta.close();
con.close();
} catch (Exception e) {
System.err.println("Exception: "+e.getMessage());
e.printStackTrace();
}
}
}
As I mentioned above setCharacterStream(int parameterIndex, Reader reader) will not work with JDBC 3.0 drivers.
Here is what I got with the "Test 1" section open in my program. Remember that Oracle JDBC driver 1.0 is a JDBC 3.0 driver.
C:\>java -cp .;\local\lib\ojdbc14.jar OracleClobSetCharacterStream
Exception in thread "main" java.lang.AbstractMethodError: oracle
.jdbc.driver.T4CPreparedStatement.setCharacterStream(
ILjava/io/Reader;)V
at OracleClobSetCharacterStream.main(
OracleClobSetCharacterStream.java:35)
"Test 2" also failed for the same reason - fileIn.length() returns "long" and that setCharacterStream(int, Reader, long)
is JDBC 4.0 method:
C:\>java -cp .;\local\lib\ojdbc14.jar OracleClobSetCharacterStream
Exception in thread "main" java.lang.AbstractMethodError: oracle
.jdbc.driver.T4CPreparedStatement.setCharacterStream(
ILjava/io/Reader;J)V
at OracleClobSetCharacterStream.main(
OracleClobSetCharacterStream.java:39)
Of course, "Test 3" worked nicely.
C:\>java -cp .;\local\lib\ojdbc14.jar OracleClobSetCharacterStream
The inserted record:
Subject = Test of setCharacterStream() methods
Body = /**
* OracleClobSetCharacterStream.java
* Copyright (c) 2007 by Dr. Herong Yang. All rights reserved.
*/
import java.io.*;
import java.sql.*;
public class OracleClobSetCharacterStream {
public static void main(String [] args) {
Connection con = nu
