JDBC 操作 oracle blob

jdbc 插入、讀取oracle blob字段

package com.ssgm.jyu.jdbc;
import java.io.*;
import java.sql.*;

import oracle.sql.*;
import oracle.jdbc.*;

public class JdbcBlob {
    public static void main(String[] args){
        Connection conn = null;
        Statement stmt = null;
        try{
            Class.forName("oracle.jdbc.driver.OracleDriver");
        }
        catch(ClassNotFoundException e){
            e.printStackTrace();
        }

        try{
            conn = DriverManager.getConnection("jdbc:oracle:thin:@Host:1521:SID","username","passwd");
            stmt = conn.createStatement();
            conn.setAutoCommit(false);
            String sourceDir = "C:\\temp\\";
            String targetDir = "C:\\temp\\retrieved\\";
            String fileName = "cbr_order_version.dmp";
            System.out.println("Writing BLOB to blob_content...");
            writeBLOB(stmt,sourceDir+fileName);
            System.out.println("Reading BLOB from blob_content...");
            readBLOB(stmt,fileName,sourceDir,targetDir);
        }
        catch(SQLException e){
            e.printStackTrace();
        }
        finally{
            try{
                stmt.close();
                conn.close();
            }
            catch(SQLException e){
                e.printStackTrace();
            }
        }
       }

        public static void writeBLOB(Statement stmt, String fullName){
            ResultSet blobRS = null;
            try{
                String sqlInsert = "INSERT INTO blob_content VALUES ('"+fullName+"',EMPTY_BLOB())";
                String sqlSelect = "SELECT blob_column FROM blob_content WHERE file_name='"+fullName+"' FOR UPDATE";

                //step1: initialize the LOB column to set the LOB locator                
                stmt.executeUpdate(sqlInsert);

                //step2: retrieve the row containing the LOB locator
                blobRS = stmt.executeQuery(sqlSelect);
                blobRS.next();

                //step3: create a LOB obj and read the LOB locator
                BLOB myBlob = ((OracleResultSet) blobRS).getBLOB("blob_column");

                //step4: get the chunksize of the LOB from the LOB object
                int chunkSize = myBlob.getChunkSize();

                //step5: create a buffer to hold a block of data from the file
                byte[] byteBuffer = new byte[chunkSize];

                //step6: create a file obj to open the file
                File file = new File(fullName);

                //step7: create an input stream obj to read the file contents
                FileInputStream in = new FileInputStream(file);

                //step8: read the file contents and write it to the LOB
                long position = 1;
                int bytesRead;

                while((bytesRead = in.read(byteBuffer)) != -1){
                    //write the buffer contents to myBlob
                    myBlob.setBytes(position, byteBuffer);
                    position += bytesRead;
                }

                //step9: commit
                stmt.execute("COMMIT");

                //step10: close the objects used to read the file
                in.close();
                blobRS.close();

                System.out.println("Wrote content from "+fullName+" to BLOB\n");
            }
            catch(SQLException e){
                System.out.println("Error Code: "+e.getErrorCode());
                System.out.println("Error Message: "+e.getMessage());
                e.printStackTrace();
            }
            catch(IOException e){
                System.out.println("Error Message: "+e.getMessage());
                e.printStackTrace();
            }
        }


        public static void readBLOB(
                Statement stmt,
                String fileName,
                String sourceDir,
                String targetDir){
            String sqlSelect = "SELECT blob_column FROM blob_content WHERE file_name='"+
              sourceDir+fileName+"'";
            ResultSet blobRS = null;
            try{
                //step1: retrieve the row containing the BLOB locator
                blobRS = stmt.executeQuery(sqlSelect);
                blobRS.next();

                //step2: create a LOB obj and read the LOB locator
                BLOB myBlob = ((OracleResultSet) blobRS).getBLOB("blob_column");

                //step3: get the chunk size of the LOB from the LOB obj
                int chunkSize = myBlob.getChunkSize();

                //setp4: create a buffer to hold a chunk of data from LOB
                byte[] byteBuffer = new byte[chunkSize];

                //step5: create a file obj
                String saveFile = targetDir + "retrievedBLOB"+fileName;
                File file = new File(saveFile);

                //step6: create output stream obj to write the LOB contents
                FileOutputStream out = new FileOutputStream(file);

                //step7: get the long of LOB contents
                long blobLength = myBlob.length();

                //step8: read a chunk of data from myBlob,
                //then write the buffer contents to file
                for (long position=1; position<=blobLength; position += chunkSize){
                    int bytesRead = myBlob.getBytes(position, chunkSize, byteBuffer);
                    out.write(byteBuffer);
                }

                //step9: close the stream obj
                out.close();

                System.out.println("Read BLOB and save file"+saveFile);
            }
            catch(SQLException e){
                System.out.println("Error Code: "+e.getErrorCode());
                System.out.println("Error Message: "+e.getMessage());
                e.printStackTrace();
            }
            catch(IOException e){
                System.out.println("Error Message: "+e.getMessage());
                e.printStackTrace();
            }
        }

    }

原文參考：http://blog.csdn.net/zhyuh_perl/article/details/7247324