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Java读写Oracle BLOB字段示例

Posted on 2013-05-28 13:33 zolly 阅读(1935) 评论(1)  编辑  收藏
导入导出Oracle BLOB字段不能使用SQL,可以使用EXP或者EXPDP

EXP导出示例:
exp name/password@orcl file=E:/exp.dump log=E:/exp.log table=(tb_emp) query="""where UserName='FN'"""

EXPDP导出示例:
Sample.bat
expdp name/password@orcl parfile=E:/expdp.par
expdp.par
DIRECTORY=dir_dump
DUMPFILE=backup.dump
LOGFILE=backup.log
TABLES=pr_data_admin
QUERY=pr_data_admin:"where UserName='FN'"

以上方法因为我电脑上的Oracle版本对不上,总是报错,后来采用java的方法,本文主要介绍如何使用java读写Oracle的BLOB字段,达到复制转移BLOB数据的目的。代码如下,加入ojdbc.jar,复制代码可以直接运行:
DBConnection.java
package com.zolly.blob;

import java.sql.Connection;
import java.sql.DriverManager;

public class DBConnection {

    public static Connection getDBConnectionFrom() throws Exception {
        Connection con = null;
        String driver = "oracle.jdbc.driver.OracleDriver";// database driver
        String url = "jdbc:oracle:thin:@192.168.1.2:1545:ORCL";// database URL
        String user = "user1"; // database name
        String password = "password1"; // database Password
        Class.forName(driver);
        con = DriverManager.getConnection(url, user, password);
        return con;
    }
    
    public static Connection getDBConnectionTo() throws Exception {
        Connection con = null;
        String driver = "oracle.jdbc.driver.OracleDriver";// database driver
        String url = "jdbc:oracle:thin:@192.168.1.3:1521:ORCL";// database URL
        String user = "user2"; // database name
        String password = "password2"; // database Password
        Class.forName(driver);
        con = DriverManager.getConnection(url, user, password);
        return con;
    }

}

BLOBUtil.java
package com.zolly.blob;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import oracle.sql.BLOB;

public class BLOBUtil {
    @SuppressWarnings("deprecation")
    public static void writeBLOB() {
        Connection con = null;
        long start = System.currentTimeMillis(); // count runtime
        InputStream fin = null;
        OutputStream outStream = null;
        String path = "E:\\requestor.txt";
        File file = new File(path);
        try {
            con = DBConnection.getDBConnectionTo();
            con.setAutoCommit(false);

            Statement stmt = con.createStatement();
            ResultSet rs = stmt
                    .executeQuery("select pzPVStream from pr_data_admin where pxInsName='PEGA!BROWSER' for update");
            // get specially columns and rows for update
            while (rs.next()) {
                // System.out.print(rs.getInt(1)+rs.getString(2)+"\n");//print
                
// select sql for debug
                BLOB blob = (BLOB) rs.getBlob("pzPVStream");
                outStream = blob.getBinaryOutputStream();
                fin = new FileInputStream(file); // put file into stream
                byte[] b = new byte[blob.getBufferSize()];
                int len = 0;
                while ((len = fin.read(b)) != -1) {
                    outStream.write(b, 0, len);
                }

                fin.close();
                outStream.flush();
                outStream.close();
            }
            System.out.print("\nupdate ok\n");

            con.commit();

            con.close();
        }

        catch (Exception e) {
            e.printStackTrace();
        }

        long end = System.currentTimeMillis();
        System.out.println(end - start);
    }

    public static void readBLOB() {
        Connection con = null;
        long start = System.currentTimeMillis(); // count runtime
        String path = "E:\\requestor.txt";
        File file = new File(path);
        try {
            con = DBConnection.getDBConnectionFrom();
            con.setAutoCommit(false);
            Statement stmt = con.createStatement();
            ResultSet rs = stmt
                    .executeQuery("select pzPVStream from pr_data_admin where pxInsName='PEGA!BROWSER'");
            // get blob form your table
            if (rs.next()) {
                BLOB blob = (BLOB) rs.getBlob("pzPVStream");
                // get word column
                FileOutputStream output = new FileOutputStream(file);
                // define a file output stream
                InputStream input = blob.getBinaryStream();// put blob into
                                                            
// input
                byte[] buffer = new byte[blob.getBufferSize()];
                // if use 1024 it will lose some bytes
                int len = 0;
                while ((len = input.read(buffer)) != -1) {
                    // get all input stream into output file stream
                    output.write(buffer, 0, len);
                    input.close();
                    output.flush();
                    output.close();
                }
                System.out.print("\ndownload ok\n");
            }
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        long end = System.currentTimeMillis();
        System.out.println(end - start);

    }

    public static void main(String[] args) {
        BLOBUtil.readBLOB();
        BLOBUtil.writeBLOB();
    }

}

评论

# re: Java读写Oracle BLOB字段示例  回复  更多评论   

2014-03-14 16:59 by rivers
while ((len = input.read(buffer)) != -1)
循环错了。
while ((len = input.read(buffer)) != -1) {
// get all input stream into output file stream
output.write(buffer, 0, len);
}
input.close();
output.flush();
output.close();

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