介绍
首先通过下面的图来展示一下从oracle到db2的流程：

从上面的图可以看到把oracle的数据移植到db2数据库中我们的java程序起到一个转换器的作用，把oracle中的不同的数据类型映射为相应的db2数据库中的类型同时把从oracle中查询出的数据插入到db2数据库中从而完成整个移植过程。下面我就结合java程序给大家是如何实现这一功能的

1．导入必需的java类

import java.text.*;import java.util.*;import java.io.*;import java.sql.*;import java.lang.*;

2.下面是从属性文件中读取在转换器使用的配置信息

//下面的代码是读属性文件的信息properties props=new properties();file f=new file("oracletodb2.properties");fileinputstream in=new fileinputstream(f);props.load(in);string db2_dbname=props.getproperty("db2_dbname");string db2_username=props.getproperty("db2_username");string db2_password=props.getproperty("db2_password");string oracle_url=props.getproperty("oracle_url");string oracle_dbname=props.getproperty("oracle_dbname");string oracle_username=props.getproperty("oracle_username");string oracle_password=props.getproperty("oracle_password");string io_tables=props.getproperty("io_tables");

通过java的输入流来读取文件中的内容
其中

1. oracletodb2.properties为属性文件名；
2. db2_dbname, db2_username, db2_password 分别为目标db2数据库的数据库名，数据库用户名，口令。
3. oracle_url ，oracle_dbname，oracle_username，oracle_password分别为oracle数据库的地址，数据库名，用户名，口令。
4. io_tables为从oracle移植到db2的表名
   下面是属性文件的全部内容：

   db2_dbname=db2databasenamedb2_username=db2usernamedb2_password=db2passworddb2_host=127.0.0.1oracle_url=127.0.0.1oracle_dbname=oracledatabasenameoracle_username=oracleusernameoracle_password=oraclepasswordio_tables=io_tables

3．接着分别建立db2和oracle数据库的连接
其中的参数为从属性文件中读入的值，jdbc用的是廋客户机的type4：

drivermanager.registerdriver(new com.ibm.db2.jdbc.app.db2driver());class.forname ("oracle.jdbc.driver.oracledriver").newinstance ();connection connora = drivermanager.getconnection("jdbc:db2:"+db2_dbname,  db2_username,db2_password); //connection connora = drivermanager.getconnection("jdbc:db2://"+db2_host+":"+db2_port+"/"+db2_dbname,  db2_username,db2_password); connection conndb2 =drivermanager.getconnection("jdbc:oracle:thin:@"+oracle_url+":1521:"+oracle_dbname,oracle_username, oracle_password);

4.转换器的核心java类
转换器的核心java类的方法为一个静态的java方法migratetable，我在代码中给解释具体的功能的内容和为什么:

//引入oracle和db2的连接及需要移植的表public static void migratetable(connection connora, connection conndb2, string strtablename)		throws exception	{//进行防错处理		if (strtablename.length() < 3)			return;	int nrows = 0;			filewriter fw = null;	printwriter pw = null;	statement stmt = null;	resultset rst = null;	statement stmtdelete = null;	preparedstatement stmtup = null;			try	{     //记录转换过程中的信息		fw = new filewriter("oracletodb2.log", true);		pw = new printwriter(fw);					system.out.println("migrating table " + strtablename);		pw.println("migrating table " + strtablename);       //确定连接赋予sql语句		stmt = connora.createstatement();      //进行表内容的查询		rst = stmt.executequery("select * from " + strtablename);	  //读入表的元数据		resultsetmetadata meta = rst.getmetadata();		string strsql = "insert into " + strtablename;		string strfields = "(";		string strvalues = "  values(";	  //根据读入的表的元数据的内容进行递归的读取		object arobjdata[] = new object[meta.getcolumncount()];			for (int i = 0; i < arobjdata.length; i ++)		{			if (i > 0)			{				strvalues = strvalues + ", ";				strfields = strfields + ", ";			}							strvalues = strvalues + "?";							strfields = strfields + meta.getcolumnname(i + 1);						}		strvalues = strvalues + ")";		strfields = strfields + ")";		strsql = strsql + strfields + strvalues;	     //建立db2数据库的连接		stmtdelete = conndb2.createstatement();         //删除原db2数据库表中的数据		stmtdelete.executeupdate("delete from " +  strtablename);		stmtdelete.close();		stmtup = conndb2.preparestatement(strsql);					while (rst.next())		{ 			for (int i = 0; i < arobjdata.length; i ++)			{				arobjdata[i] = rst.getobject(i + 1);//进行二进制、字符类型的转换				if (arobjdata[i] != null && arobjdata[i] instanceof string)					arobjdata[i] = (object)iso2gb((string)arobjdata[i]);			}				for (int i = 0; i < arobjdata.length; i ++)			{				if (meta.getcolumntype(i + 1) == java.sql.types.blob)				{					byte ardata[] = null;					if (arobjdata[i] != null)					ardata = ((blob)arobjdata[i]).getbytes(1l, (int)((blob)arobjdata[i]).length());				//读取二进制的数据								stmtup.setbytes(i + 1, ardata);				}				else if (meta.getcolumntype(i + 1) == java.sql.types.clob)				{					string strdata = null;					if (arobjdata[i] != null)					strdata = ((clob)arobjdata[i]).getsubstring(1l, (int)((clob)arobjdata[i]).length());												stmtup.setstring(i + 1, iso2gb(strdata));				}				else				{					if (arobjdata[i] != null)						stmtup.setobject(i + 1, arobjdata[i]);					else						stmtup.setstring(i + 1, null);				}			}							stmtup.executeupdate();				//计数器表示一个表中移植了多少行				nrows ++;			}

上面的代码示整个转换器的关键部分，它实现了整个移植过程的大部分功能而且可以实现代码页，二进制的数据的移植是一个功能强大的移植工具。下面我就运行的步骤作详细的演示：

1. 在操作系统上的类路径中加入jdk的路径。
2. 配置属性文件。
3. 把oracle数据库中的表结构倒成.ddl文件，并调整其中的数据类型映射为db2中的类型建立表。
4. 编译整个java文件
5. 执行
6. 查看日志信息

下面是整个程序的完整代码：

import java.text.*;import java.util.*;import java.io.*;import java.sql.*;import java.lang.*;public class oracletodb2{	public static void main(string[] args)		throws exception	{      		//下面的代码是读属性文件的信息		properties props=new properties();		file f=new file("oracletodb2.properties");        fileinputstream in=new fileinputstream(f);        props.load(in);        string db2_dbname=props.getproperty("db2_dbname");        string db2_username=props.getproperty("db2_username");        string db2_password=props.getproperty("db2_password");        string oracle_url=props.getproperty("oracle_url");        string oracle_dbname=props.getproperty("oracle_dbname");        string oracle_username=props.getproperty("oracle_username");        string oracle_password=props.getproperty("oracle_password");        string io_tables=props.getproperty("io_tables");        //建立db2和oracle数据库的分别连接        // string db2_url = "jdbc:db2://"+db2_host+":"+db2_port+"/"+db2_dbname;		drivermanager.registerdriver(new com.ibm.db2.jdbc.app.db2driver());		//drivermanager.registerdriver(new com.ibm.db2.jdbc.net.db2driver());		class.forname ("oracle.jdbc.driver.oracledriver").newinstance ();		connection connora = drivermanager.getconnection("jdbc:db2:"+db2_dbname,  db2_username,db2_password); 		//connection connora = drivermanager.getconnection("		jdbc:db2://"+db2_host+":"+db2_port+"/"+db2_dbname,  db2_username,db2_password); 				connection conndb2 = drivermanager.getconnection("		jdbc:oracle:thin:@"+oracle_url+":1521:"+oracle_dbname,oracle_username, oracle_password);				filereader reader = new filereader(io_tables);		linenumberreader lreader = new linenumberreader(reader);				string strtable = null;				while ((strtable = lreader.readline()) != null)		{			try			{				migratetable(connora, conndb2, strtable);			}			catch (exception e)			{				e.printstacktrace();			}		}				reader.close();				connora.close();		conndb2.close();				system.out.println("ok");	}public static void migratetable(connection connora, connection conndb2, string strtablename)	throws exception{	if (strtablename.length() < 3)		return;	int nrows = 0;			filewriter fw = null;	printwriter pw = null;	statement stmt = null;	resultset rst = null;	statement stmtdelete = null;	preparedstatement stmtup = null;			try	{		fw = new filewriter("oracletodb2.log", true);		pw = new printwriter(fw);				system.out.println("migrating table " + strtablename);		pw.println("migrating table " + strtablename);		stmt = connora.createstatement();		rst = stmt.executequery("select * from " + strtablename);			resultsetmetadata meta = rst.getmetadata();					string strsql = "insert into " + strtablename;		string strfields = "(";		string strvalues = "  values(";			object arobjdata[] = new object[meta.getcolumncount()];			for (int i = 0; i < arobjdata.length; i ++)		{			if (i > 0)			{				strvalues = strvalues + ", ";				strfields = strfields + ", ";			}							strvalues = strvalues + "?";							strfields = strfields + meta.getcolumnname(i + 1);						}			strvalues = strvalues + ")";		strfields = strfields + ")";		strsql = strsql + strfields + strvalues;			stmtdelete = conndb2.createstatement();		stmtdelete.executeupdate("delete from " +  strtablename);		stmtdelete.close();		stmtup = conndb2.preparestatement(strsql);					while (rst.next())		{ 			for (int i = 0; i < arobjdata.length; i ++)			{				arobjdata[i] = rst.getobject(i + 1);				if (arobjdata[i] != null && arobjdata[i] instanceof string)					arobjdata[i] = (object)iso2gb((string)arobjdata[i]);			}				for (int i = 0; i < arobjdata.length; i ++)			{				if (meta.getcolumntype(i + 1) == java.sql.types.blob)				{					byte ardata[] = null;					if (arobjdata[i] != null)					ardata = ((blob)arobjdata[i]).getbytes(1l, (int)((blob)arobjdata[i]).length());												stmtup.setbytes(i + 1, ardata);				}				else if (meta.getcolumntype(i + 1) == java.sql.types.clob)				{					string strdata = null;					if (arobjdata[i] != null)					strdata = ((clob)arobjdata[i]).getsubstring(1l, (int)((clob)arobjdata[i]).length());												stmtup.setstring(i + 1, iso2gb(strdata));				}				else				{					if (arobjdata[i] != null)						stmtup.setobject(i + 1, arobjdata[i]);					else						stmtup.setstring(i + 1, null);				}			}							stmtup.executeupdate();							nrows ++;		}					pw.println("" + nrows + " rows migrated");		system.out.println("" + nrows + " rows migrated");	}	catch(exception e)	{		if (pw != null)			e.printstacktrace(pw);					e.printstacktrace();	}	finally	{		try		{			if (rst != null)				rst.close();		}		catch (exception ee)		{			ee.printstacktrace(pw);		}						try		{			if (stmt != null)				stmt.close();		}		catch (exception ee)		{			ee.printstacktrace(pw);		}						try		{			if (stmtdelete != null)				stmtdelete.close();		}		catch (exception ee)		{			ee.printstacktrace(pw);		}						try		{			if (stmtup != null)				stmtup.close();		}		catch (exception ee)		{			ee.printstacktrace(pw);		}		if (fw != null)		{			fw.flush();			fw.close();		}	}}