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import java.sql.*; import java.io.*; import oracle.sql.*; import oracle.jdbc.*; /** * @author Sean * @version 1.0 * @date 2005/8/24 */ public class LobExample2 { public static void readCLOB(Statement stmt,String fileName, String sourceDirectory,String targetDirectory) throws SQLException,IOException { //step 1 : 将包含LOB定位器的行读入结果集 ResultSet rs = stmt.executeQuery("select clob_column from clob_content "); //step 2 : 在JAVA程序中创建一个LOB对象，并且将LOB定位器从结果集读入这个LOB对象。 rs.next(); oracle.sql.CLOB myClob = ((OracleResultSet)rs).getCLOB(1); //ste[ 3 : 从LOB对象获取LOB的组块大小 int chunkSize = myClob.getChunkSize(); //step 4 : 创建一个缓冲区来存储自LOB对象的数据组块 char[] charBuffer = new char[chunkSize]; //step 5 : 创建一个文件对象 String saveFile = targetDirectory +"retrievedCLOB"+ fileName; File myFile = new File(saveFile); //step 6 : 创建输出流对象以便将LOB内容写到新文件 OutputStreamWriter myOutputStreamWriter = new OutputStreamWriter ( new FileOutputStream (myFile)); BufferedWriter myBufferedWriter = new BufferedWriter(myOutputStreamWriter); //step 7 : 从LOB对象获取LOB内容的长度 long clobLength = myClob.length(); //step 8 : 将数据组块从LOB对象读入到第四步中创建的缓冲区。将缓冲区的内容写到新文件 for(long position = 1 ; position<=clobLength;position += chunkSize) { int charRead = myClob.getChars(position,chunkSize,charBuffer); myBufferedWriter.write(charBuffer); } // end of for //step 9 : 关闭流对象 myBufferedWriter.close(); myOutputStreamWriter.close(); System.out.println("Read CLOB and saved file " + saveFile); } // end of readCLOB public static void readBLOB(Statement stmt,String fileName, String sourceDirectory,String targetDirectory) throws SQLException,IOException { ResultSet rs = stmt.executeQuery("select blob_column from blob_content "); rs.next(); oracle.sql.BLOB myBlob = ((OracleResultSet)rs).getBLOB(1); int chunkSize = myBlob.getChunkSize(); long blobLength = myBlob.length(); byte[] bytesBuffer = new byte[chunkSize]; String saveFile = targetDirectory + "readBLOB"+fileName; FileOutputStream myFileOutputStream = new FileOutputStream ( new File(saveFile)); for (long position = 1 ; position <= blobLength ; position += chunkSize) { int byteRead = myBlob.getBytes(position,chunkSize,bytesBuffer); myFileOutputStream.write(bytesBuffer); } // end of for myFileOutputStream.close(); System.out.println("Read BLOB and saved file "+saveFile); } // end of readBLOB public static void retrievedBFILE(Statement stmt,String fileName, String targetDirectory) throws SQLException,IOException { ResultSet rs = stmt.executeQuery("select bfile_column from bfile_content "); rs.next(); oracle.sql.BFILE myBfile = ((OracleResultSet)rs).getBFILE(1); String bfileName = myBfile.getName(); myBfile.fileExists(); myBfile.openFile(); InputStream myInputStream = myBfile.getBinaryStream(); String saveFile = targetDirectory + "retrievedBFILE"+bfileName; saveFile(myInputStream,saveFile); myInputStream.close(); myBfile.closeFile(); System.out.println("Read BFILE and save file "+saveFile); } // end of retrievedBFILE public static void saveFile(InputStream myInputStream,String fileName) throws IOException { FileOutputStream myFileOutputStream = new FileOutputStream ( new File (fileName)); byte[] byteBuffer = new byte[8132]; int byteRead; while((byteRead = myInputStream.read(byteBuffer)) != -1 ) { myFileOutputStream.write(byteBuffer); } //end of while myFileOutputStream.close(); } // end of saveFile public static void main(String[] args) throws SQLException,IOException { DriverManager.registerDriver(new OracleDriver()); Connection conn = DriverManager.getConnection("jdbc:oracle:thin:swatt/swgood@10.10.10.251:1521:test"); conn.setAutoCommit(false); Statement stmt = conn.createStatement(); String sourceDirectory = "D:\\JSPBook\\JDBC\\JDBC_book\\sample_files\\"; String targetDirectory = "D:\\JSPBook\\JDBC\\JDBC_book\\sample_files\\retrieved\\"; readCLOB(stmt,"textContent.txt",sourceDirectory,targetDirectory); readBLOB(stmt,"binaryContent.doc",sourceDirectory,targetDirectory); retrievedBFILE(stmt,"textContent.txt",targetDirectory); stmt.close(); conn.close(); } // end of main }//end of LobExample2