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

 Installing and Running Java DB - Derby

 Derby (Java DB) JDBC Driver

 Derby (Java DB) JDBC DataSource Objects

 Java DB (Derby) - DML Statements

 Java DB (Derby) - ResultSet Objects of Queries

 Java DB (Derby) - PreparedStatement

 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

 Oracle Express Edition Installation on Windows

 Oracle JDBC Drivers

 Oracle - Reference Implementation of JdbcRowSet

 Oracle - PreparedStatement

 Oracle - JBDC CallableStatement

 Oracle CLOB (Character Large Object) - TEXT

 Oracle BLOB (Binary Large Object) - BLOB

 Microsoft SQL Server Express Edition

 Microsoft JDBC Driver for SQL Server

 Microsoft JDBC Driver - Query Statements and Result Sets

 Microsoft JDBC Driver - DatabaseMetaData Object

 Microsoft JDBC Driver - DDL Statements

 Microsoft JDBC Driver - DML Statements

 SQL Server - PreparedStatement

 SQL Server CLOB (Character Large Object) - TEXT

 SQL Server BLOB (Binary Large Object) - BLOB

 JDBC-ODBC Bridge Driver - sun.jdbc.odbc.JdbcOdbcDriver

 JDBC-ODBC Bridge Driver - Flat Text Files

 JDBC-ODBC Bridge Driver - MS Access

 JDBC-ODBC Bridge Driver - MS SQL Server

 Summary of JDBC Drivers and Database Servers

 Using Connection Pool with JDBC

 Archived Tutorials

 References

 Full Version in PDF/EPUB