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:

To test those setCharacterStream() methods, wrote the following program:

/* MySqlClobSetCharacterStream.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import java.sql.*;
public class MySqlClobSetCharacterStream {
  public static void main(String [] args) {
    Connection con = null;
    try {
      com.mysql.cj.jdbc.MysqlDataSource ds
        = new com.mysql.cj.jdbc.MysqlDataSource();
      ds.setServerName("localhost");
      ds.setPortNumber(3306);
      ds.setDatabaseName("HerongDB");
      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 (Subject, Body) VALUES (?,?)");
      ps.setString(1, subject);
      Reader bodyIn =
        new FileReader("MySqlClobSetCharacterStream.java");

// Test 1 - This works with JDBC 4.0 drivers, not with JDBC 3.0
//      ps.setCharacterStream(2, bodyIn);

// Test 2 - This works with JDBC 4.0 drivers, not with JDBC 3.0
//      File fileIn = new File("MySqlClobSetCharacterStream.java");
//      ps.setCharacterStream(2, bodyIn, fileIn.length());

// Test 3 - This works with JDBC 3.0 and 4.0 drivers
      File fileIn = new File("MySqlClobSetCharacterStream.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();
    }
  }
}

Since MySQL Connector J 8.0.19 is a JDBC 4.2 driver, all 3 tests are working:

herong> java -cp .:mysql-connector-java.jar \
   MySqlClobSetCharacterStream.java

The inserted record:
   Subject = Test of setCharacterStream() methods
   Body = /* MySqlClobSetCharacterStream.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import java.sql.*;
public class MySqlClobSetCharacterStream {
  public static void main(String [] args) {
    Connection con = null;

If you are using a JDBC 3.0 driver, setCharacterStream(int parameterIndex, Reader reader) will not work. Here is what I got with the "Test 1" section open in my program with mysql-connector-java-5.0.7-bin.jar:

herong> java -cp .:mysql-connector-java-5.0.7-bin.jar
   MySqlClobSetCharacterStream

Exception in thread "main" java.lang.AbstractMethodError: com.mysql
  .jdbc.PreparedStatement.setCharacterStream(ILjava/io/Reader;)V
  at MySqlClobSetCharacterStream.main(MySqlClobSetCharac...java:34)

"Test 2" also failed with mysql-connector-java-5.0.7-bin.jar for the same reason - fileIn.length() returns "long" and that setCharacterStream(int, Reader, long) is JDBC 4.0 method:

herong> java -cp .:mysql-connector-java-5.0.7-bin.jar
  MySqlClobSetCharacterStream

Exception in thread "main" java.lang.AbstractMethodError: com.mysql
  .jdbc.PreparedStatement.setCharacterStream(ILjava/io/Reader;J)V
  at MySqlClobSetCharacterStream.main(MySqlClobSetCharac...java:38)

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 MySQL Installation on Windows

 MySQL JDBC Driver (MySQL Connector/J)

 MySQL - PreparedStatement

 MySQL - Reference Implementation of JdbcRowSet

 MySQL - JBDC CallableStatement

MySQL CLOB (Character Large Object) - TEXT

 Overview of CLOB (Character Large Object)

 Create Tables with CLOB Columns

 Inserting CLOB Values with SQL INSERT Statements

 Inserting CLOB Values with setString() Method

Inserting CLOB Values with setCharacterStream() Method

 Retrieving CLOB Values with getString() Method

 Retrieving CLOB Values with getCharacterStream() Method

 Retrieving CLOB Values with getClob() Method

 Inserting CLOB Values with setClob() Method

 MySQL BLOB (Binary Large Object) - BLOB

 Using Connection Pool with JDBC

 Archived Tutorials

 References

 Full Version in PDF/EPUB