Closing InputStream Too Early on setCharacterStream()

This section describes an error condition where executeUpdate() gives an exception if the Reader is closed too early.

The program in the previous tutorial worked nicely. But if you make a mistake by placing the bodyIn.close() statement before ps.executeUpdate(), you may get an IOException when ps.executeUpdate() is called. The reason is simple, reading of data from the Reader is done at the time of executeUpdate() call, not before. Here is a test program:

/* OracleClobSetCharacterStreamError.java
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
import java.io.*;
import java.sql.*;
public class OracleClobSetCharacterStreamError {
  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 = "Error test of setCharacterStream()";
      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 (4,?,?)");
      ps.setString(1, subject);
      Reader bodyIn = 
        new FileReader("OracleClobSetCharacterStreamError.java");
      File fileIn = new File(
        "OracleClobSetCharacterStreamError.java");
      ps.setCharacterStream(2, bodyIn, (int) fileIn.length());

// Error - Closing the Reader too early.
      bodyIn.close();

      int count = ps.executeUpdate();
      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) {
      e.printStackTrace();
    }
  }
}

Surprisingly, I did not get any I/O exceptions. May be the Oracle JDBC driver reads data at the time of setCharacterStream() call. The program executed correctly:

C:\herong>\Progra~1\java\jdk1.8.0_45\bin\java 
   -cp .;\local\lib\ojdbc14.jar OracleClobSetCharacterStreamError

The inserted record:
   Subject = Error test of setCharacterStream()
   Subject = Error test of setCharacterStream()
   Body = /* OracleClobSetCharacterStreamError.java
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
import java.io.*;
import java.sql.*;
public class OracleClobSetCharacterStreamError {
  public static void main(String [] args) {
    Connection con =

Last update: 2015.

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

 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

 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

Closing InputStream Too Early on setCharacterStream()

 Retrieving CLOB Values with getString() Method

 Retrieving CLOB Values with getCharacterStream() Method

 Retrieving CLOB Values with getClob() Method

 Inserting CLOB Values with setClob() Method

 Oracle BLOB (Binary Large Object) - BLOB

 Microsoft SQL Server 2005 Express Edition

 Microsoft JDBC Driver for SQL Server - sqljdbc42.jar

 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

 Additional Tutorial Notes to Be Added

 Outdated Tutorials

 References

 PDF Printing Version