JDBC Tutorials - Herong's Tutorial Examples - v3.12, by Dr. Herong Yang
Closing InputStream Too Early on setBinaryStream()
This section describes an error condition where executeUpdate() gives an exception if the InputStream 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 will get an IOException when ps.executeUpdate() is called. The reason is simple, reading of binary data from the InputStream is done at the time of executeUpdate() call. Here is a test program:
/* OracleBlobSetBinaryStreamError.java * Copyright (c) HerongYang.com. All Rights Reserved. */ import java.io.*; import java.sql.*; public class OracleBlobSetBinaryStreamError { 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 setBinaryStream() method"; Statement sta = con.createStatement(); sta.executeUpdate("DELETE FROM Image WHERE Subject = '" +subject+"'"); // Inserting CLOB value with PreparedStatement.setBinaryStream() PreparedStatement ps = con.prepareStatement( "INSERT INTO Image (ID, Subject, Body) VALUES (4,?,?)"); ps.setString(1, subject); InputStream bodyIn = new FileInputStream("OracleBlobSetBinaryStreamError.class"); File fileIn = new File("OracleBlobSetBinaryStreamError.class"); ps.setBinaryStream(2, bodyIn, (int) fileIn.length()); // Error - Closing the InputStream too early. bodyIn.close(); int count = ps.executeUpdate(); ps.close(); // Retrieving BLOB value with getBytes() sta = con.createStatement(); ResultSet res = sta.executeQuery("SELECT * FROM Image" +" WHERE Subject = '"+subject+"'"); res.next(); System.out.println("The inserted record: "); System.out.println(" Subject = "+res.getString("Subject")); System.out.println(" Body = " +new String(res.getBytes("Body"),0,32)); res.close(); sta.close(); con.close(); } catch (Exception e) { e.printStackTrace(); } } }
Surprisingly, this program works with newer versions of JDBC driver. Somehow it does not care when the InputStrean object is closed.
herong> java -cp .;ojdbc11.jar OracleBlobSetBinaryStreamError The inserted record: Subject = Error test of setBinaryStream() method Body = ???? 4 ? : G H ? I ? J
When executing the same program with JDK 1.6, Oracle 10.2 and ojdbc14.jar, I did get the expected exception:
herong> Progra~1\java\jdk1.6.0_2\bin\java \ -cp .;ojdbc14.jar OracleBlobSetBinaryStreamError Exception: Io exception: Read error java.sql.SQLException: Io exception: Read error at oracle.jdbc.driver.DatabaseError.throwSqlException( DatabaseError.java:...) at oracle.jdbc.driver.T4CPreparedStatement.executeForRows( T4CPreparedStatement.java:988) at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout( OracleStatement.java:1170) at oracle.jdbc.driver.OraclePreparedStatement.executeInternal( OraclePreparedStatement.java:3339) at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate( OraclePreparedStatement.java:3423) at OracleBlobSetBinaryStreamError.main( OracleBlobSetBinaryStreamError.java:39)
Table of Contents
JDBC (Java Database Connectivity) Introduction
Installing and Running Java DB - Derby
Derby (Java DB) JDBC DataSource Objects
Java DB (Derby) - DML Statements
Java DB (Derby) - ResultSet Objects of Queries
Java DB (Derby) - PreparedStatement
MySQL JDBC Driver (MySQL Connector/J)
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 - Reference Implementation of JdbcRowSet
Oracle - JBDC CallableStatement
Oracle CLOB (Character Large Object) - TEXT
►Oracle BLOB (Binary Large Object) - BLOB
Overview of BLOB (Binary Large Object)
Create Tables with CLOB Columns
Inserting BLOB Values with SQL INSERT Statements
Inserting BLOB Values with setBytes() Method
Inserting BLOB Values with setBinaryStream() Method
►Closing InputStream Too Early on setBinaryStream()
Retrieving BLOB Values with getBytes() Method
Retrieving BLOB Values with getBinaryStream() Method
Retrieving BLOB Values with getBlob() Method
Inserting BLOB Values with setBlob() Method
Copying BLOB Values to New Rows
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