Retrieving BLOB Values with getBinaryStream() Method

JDBC for SQL Server - Herong's Tutorial Examples

∟SQL Server BLOB (Binary Large Object) - BLOB

∟Retrieving BLOB Values with getBinaryStream() Method

This section describes how to retrieve BLOB values with the ResultSet.getBinaryStream() method.

BLOB values can also be retrieved with the getBinaryStream() method on the ResultSet object, which will return an OutputStream object. Then you can read the BLOB values from the OutputStream object with the read() method. The sample program below shows you how to create OutputStream objects with the getBinaryStream() method. A utility method is included to read all bytes from an OutputStream object and save them in a file.

/* SqlServerBlobGetBinaryStream.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import java.sql.*;
public class SqlServerBlobGetBinaryStream {
  public static void main(String [] args) {
    Connection con = null;
    try {
      com.microsoft.sqlserver.jdbc.SQLServerDataSource ds
        = new com.microsoft.sqlserver.jdbc.SQLServerDataSource();
      ds.setServerName("localhost");
//      ds.setPortNumber(60782);
      ds.setInstanceName("SQLEXPRESS");
      ds.setDatabaseName("AdventureWorks2019");
      ds.setUser("Herong");
      ds.setPassword("T0pSecret");
      con = ds.getConnection();

// Retrieving CLOB value with getBinaryStream()
      Statement sta = con.createStatement();
      ResultSet res = sta.executeQuery("SELECT * FROM Image");
      int i = 0;
      while (res.next() && i<1) {
        i++;
        System.out.println("Record ID: "+res.getInt("ID"));
        System.out.println("   Subject = "+res.getString("Subject"));
        InputStream bodyOut = res.getBinaryStream("Body");
        String fileOut = "BlobOut_"+res.getInt("ID")+".bin";
        saveOutputStream(fileOut,bodyOut);
        bodyOut.close();
        System.out.println("   Body = (Saved in "+fileOut+")");
      }
      res.close();

      sta.close();
      con.close();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  public static void saveOutputStream(String name, InputStream body) {
    int c;
    try {
      OutputStream f = new FileOutputStream(name);
      while ((c=body.read())>-1) {
        f.write(c);
      }
      f.close();
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
      e.printStackTrace();
    }
  }
}

Surprisingly, I got an exception when running this example program with newer versions of JDK, JDBBC Driver and SQL Server. The message says that the stream was closed. I don't know what was wrong.

herong> herong> java -cp .;mssql-jdbc-9.4.1.jre16.jar \
  SqlServerBlobGetBinaryStream

   Record ID: 1
   Subject = Test on INSERT statement
Exception: The stream is closed.
java.io.IOException: The stream is closed.
  at com.microsoft.sqlserver.jdbc.BaseInputStream.checkClosed(Simpl...
  at com.microsoft.sqlserver.jdbc.PLPInputStream.read(PLPInputStrea...
  at SqlServerBlobGetBinaryStream.saveOutputStream
     (SqlServerBlobGetBinaryStream.java:46)
  at SqlServerBlobGetBinaryStream.main
     (SqlServerBlobGetBinaryStream.java:30)

   Body = (Saved in BlobOut_1.bin)

Previously, when running the same example program with JDK 1.6, JDBC Dirver 1.0 and SQL Server 2005, I got two exceptions.

herong> Progra~1\java\jdk1.6.0_2\bin\javac
   -cp .;\local\lib\sqljdbc.jar
   SqlServerBlobGetBinaryStream.java

herong> Progra~1\java\jdk1.6.0_2\bin\java
   -cp .;\local\lib\sqljdbc.jar SqlServerBlobGetBinaryStream

Record ID: 1
   Subject = Test on INSERT statement

Exception: The stream was closed by result set access.
java.io.IOException: The stream was closed by result set access.
  at com.microsoft.sqlserver.jdbc.PLPInputStream.checkClosed(...)
  at com.microsoft.sqlserver.jdbc.PLPInputStream.read(...)
  at SqlServerBlobGetBinaryStream.saveOutputStream(
    SqlServerBlobGetBinaryStream.java:46)
  at SqlServerBlobGetBinaryStream.main(
    SqlServerBlobGetBinaryStream.java:30)

Exception: The stream was closed by result set access.
java.io.IOException: The stream was closed by result set access.
  at com.microsoft.sqlserver.jdbc.PLPInputStream.checkClosed(...)
  at com.microsoft.sqlserver.jdbc.PLPInputStream.close(...)
  at SqlServerBlobGetBinaryStream.main(
    SqlServerBlobGetBinaryStream.java:31)