mysql 大对象存取: 类型一般应该用mediumblod, blob只能存2的16次方个byte, mediumblod是24次方, 一般来说够用了.longblob是32次方有些大. MYSQL默认配置只能存1M大小的文件,要修改配置,WIN版本的在mysql.ini文件中 修改max_allowed_packet,net_buffer_length等几个参数,或直接SET GLOBAL varName=value. linux版本可以在启动参数后加-max_allowed_packet=xxM等几个参数. MYSQL存大对象最好直接就setBinaryStream,又快又方便. 而不要先插入空再造型成BLOB然后再setBlob 例子: import java.sql.*; import java.io.*; public class DBTest { static String driver = "org.gjt.mm.mysql.Driver"; static String url = "jdbc:mysql://localhost:3306/test"; static String user = "root"; static String passwd = "passwd"; public static void main(String[] args) throws Exception { Connection conn = null; try { Class.forName(driver); conn = DriverManager.getConnection(url,user,passwd); int op = 1; //插入 if (op == 0) { PreparedStatement ps = conn.prepareStatement("insert into tb_file values (?,?)"); ps.setString(1, "aaa.exe"); InputStream in = new FileInputStream("d:/aaa.exe"); ps.setBinaryStream(2,in,in.available()); ps.executeUpdate(); ps.close(); } else { //取出 PreparedStatement ps = conn.prepareStatement("select * from tb_file where filename = ?"); ps.setString(1, "aaa.exe"); ResultSet rs = ps.executeQuery(); rs.next(); InputStream in = rs.getBinaryStream("filecontent"); System.out.println(in.available()); FileOutputStream out = new FileOutputStream("d:/bbb.exe"); byte[] b = new byte[1024]; int len = 0; while ( (len = in.read(b)) != -1) { out.write(b, 0, len); out.flush(); } out.close(); in.close(); rs.close(); ps.close(); } } catch (Exception ex) { ex.printStackTrace(System.out); } finally { try {conn.close();} catch (Exception ex) { } } } } sqlserver 大对象存取没有什么多说的,只要是image类型就行了,注意这是column类型,有人以为它只能存 图象.image是文件镜象的意思. import java.sql.*; import java.io.*; public class DBTest { static String driver = "com.microsoft.jdbc.sqlserver.SQLServerDriver"; static String url = "jdbc:microsoft:sqlserver://192.168.0.202:9999999999;DatabaseName=dddd"; static String user = "sa"; static String passwd = "ps"; public static void main(String[] args) throws Exception { Connection conn = null; try { Class.forName(driver); conn = DriverManager.getConnection(url,user,passwd); int op = 0; //插入 if (op == 0) { PreparedStatement ps = conn.prepareStatement("insert into tb_file values (?,?)"); ps.setString(1, "aaa.exe"); InputStream in = new FileInputStream("d:/aaa.exe"); ps.setBinaryStream(2,in,in.available()); ps.executeUpdate(); ps.close(); } else { //取出 PreparedStatement ps = conn.prepareStatement("select * from tb_file where filename = ?"); ps.setString(1, "aaa.exe"); ResultSet rs = ps.executeQuery(); rs.next(); InputStream in = rs.getBinaryStream("filecontent"); System.out.println(in.available()); FileOutputStream out = new FileOutputStream("d:/bbb.exe"); byte[] b = new byte[1024]; int len = 0; while ( (len = in.read(b)) != -1) { out.write(b, 0, len); out.flush(); } out.close(); in.close(); rs.close(); ps.close(); } } catch (Exception ex) { ex.printStackTrace(System.out); } finally { try {conn.close();} catch (Exception ex) { } } } } ORACLE的大对象存储有些变态,要无论是Blob,还是CLOB都要求先插入一个空值,然后 查询并锁定这一条记录,获取对Lob的引用再进行填充,网上有太多的例子.我个人认为 这种方法垃圾得连写都不想写了,你可以自己去搜索一下. 这种特别的操作既增加操作的复杂度,又违反了JDBC接口的规范,所以我极力反对这样 使用,如果你和我有同样的观点.那么我提供另一种通用的方法.就是你不用LOB而用 oracle的LONG RAW来代替它们.这样就可以象其它对象一样操作了: create table tb_file(filename varchar2(255),filecontent LONG RAW); import java.sql.*; import java.io.*; public class BlobTest { static String driver = "oracle.jdbc.driver.OracleDriver"; static String url = "jdbc:oracle:thin:@localhost:1521:test"; static String user = "system"; static String passwd = "passwd"; public static void main(String[] args) throws Exception { Connection conn = null; try { Class.forName(driver); conn = DriverManager.getConnection(url, user, passwd); int op = 1; //插入 if (op == 0) { PreparedStatement ps = conn.prepareStatement("insert into tb_file values (?,?)"); ps.setString(1, "aaa.exe"); InputStream in = new FileInputStream("d:/aaa.exe"); ps.setBinaryStream(2,in,in.available()); ps.executeUpdate(); ps.close(); } else { //取出 PreparedStatement ps = conn.prepareStatement("select * from tb_file where filename = ?"); ps.setString(1, "aaa.exe"); ResultSet rs = ps.executeQuery(); rs.next(); InputStream in = rs.getBinaryStream("filecontent"); System.out.println(in.available()); FileOutputStream out = new FileOutputStream("d:/bbb.exe"); byte[] b = new byte[1024]; int len = 0; while ( (len = in.read(b)) != -1) { out.write(b, 0, len); out.flush(); } out.close(); in.close(); rs.close(); ps.close(); } } catch (Exception ex) { ex.printStackTrace(System.out); } finally { try { conn.close(); } catch (Exception ex) {} } } } 转自：http://dev.csdn.net/author/axman/1ca2ede425e44dba9ac20c2e262e4fb8.html