Closing InputStream Too Early on setBinaryStream()

JDBC for Oracle - Herong's Tutorial Examples

∟Oracle BLOB (Binary Large Object) - BLOB

∟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)