前天帮朋友忙写了一个有关ORACLE数据库中BLOB字段的存取，发现网上关于BLOB字段的操作没有很完整的例子，在此我将我写的程序完整的贴出来，还望朋友指教。
DBUtil类用于数据库连接
public class DBUtil {
public static String driverName = "oracle.jdbc.driver.OracleDriver";
public static String urlName = "jdbc:oracle:thin:@oracle:1521:nio";
public static String userName = "study";
public static String password = "study";
public static Connection getConnection(){
Connection conn =null;
try{
Class.forName(driverName);
conn = DriverManager.getConnection(urlName,userName,password);
}
catch(ClassNotFoundException e){
System.err.println("Register driver error!");
return null;
}
catch(SQLException e){
System.err.println("Get database connection error!");
return null;
}
return conn;
}
}
//FileLoadForm是Struts中的ActionForm
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.upload.FormFile;
public class FileLoadForm extends ActionForm {
private FormFile wordFile;
/**
* Method validate
* @param mapping
* @param request
* @return ActionErrors
*/
public ActionErrors validate(
ActionMapping mapping,
HttpServletRequest request) {
return null;
}
/**
* Method reset
* @param mapping
* @param request
*/
public void reset(ActionMapping mapping, HttpServletRequest request) {
}
/**
* @return 返回 wordFile。
*/
public FormFile getWordFile() {
return wordFile;
}
/**
* @param wordFile 要设置的 wordFile。
*/
public void setWordFile(FormFile wordFile) {
this.wordFile = wordFile;
}
}
//FileLoadAction主要实现业务逻辑，在此实现了BLOB字段的存取，如果逻辑很复杂可以使用一个辅助类来实现数据库操作。
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.upload.FormFile;
import java.io.*;
import java.sql.*;
public class FileLoadAction extends Action {
// -------------------------------------------- Instance Variables
// -------------------------------------- Methods
/**
* Method execute
* @param mapping
* @param form
* @param request
* @param response
* @return ActionForward
*/
public ActionForward execute(
ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) {
FileLoadForm fileLoadForm = (FileLoadForm) form;
FormFile wordFile = fileLoadForm.getWordFile();
Connection conn = DBUtil.getConnection();
try{
conn.setAutoCommit(false);
Statement stm = conn.createStatement();
String sql = "select decode(max(blob_id),null,0,max(blob_id)+1) from db_blob";
ResultSet rs = stm.executeQuery(sql);
int id = 0;
if(rs.next()){
id = rs.getInt(1);
}
rs.close();
sql = "insert into db_blob(blob_id,blob_name,blob_body) values("+id+",'"+wordFile.getFileName()+"',empty_blob())";
stm.executeUpdate(sql);
sql = "select blob_body from db_blob where blob_id = "+id+" for update";
rs = stm.executeQuery(sql);
if(rs.next()){
Blob blob = rs.getBlob(1);
BufferedInputStream in = new BufferedInputStream(wordFile.getInputStream());
BufferedOutputStream out = new BufferedOutputStream(((oracle.sql.BLOB)blob).getBinaryOutputStream());
int buffer = 0;
while((buffer = in.read()) != -1){
out.write(buffer);
}
out.flush();
out.close();
in.close();
}
rs.close();
stm.close();
conn.commit();
conn.close();
}
catch(Exception e){
System.err.println("insert error!");
try{
conn.rollback();
System.out.println("transaction rollback !");
}catch(Exception exp){System.err.println("rollbak error!");}
return mapping.getInputForward();
}
return mapping.findForward("success");
}
public static void main(String []args){
Connection conn = DBUtil.getConnection();
try{
Statement stm = conn.createStatement();
String sql = "select blob_body from