展示JDBC存取ORACLE大型数据对象LOB几种情况的示范类

package
 test;

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

/**
 * 展示JDBC存取ORACLE大型数据对象LOB几种情况的示范类
 *
 *
 * @version 1.0
 *
 */
public
 
class
 LobPros
{

   /**
    * ORACLE驱动程序
    */
   private
 
static
 
final
 String DRIVER = 
"oracle.jdbc.driver.OracleDriver"
;

   /**
    * ORACLE连接用URL
    */
   private
 
static
 
final
 String URL = 
"jdbc:oracle:thin:@10.11.25.66:1521:wjc"
;

   /**
    * 用户名
    */
   private
 
static
 
final
 String USER = 
"wjc"
;

   /**
    * 密码
    */
   private
 
static
 
final
 String PASSWORD = 
"anyue"
;

   /**
    * 数据库连接
    */
   private
 
static
 Connection conn = 
null
;

   /**
    * SQL语句对象
    */
   private
 
static
 Statement stmt = 
null
;

   /**
    * @roseuid 3EDA089E02BC
    */
   public
 LobPros()
   {

   }

   /**
    * 往数据库中插入一个新的CLOB对象
    *
    * @param infile - 数据文件
    * @throws java.lang.Exception
    * @roseuid 3EDA04A902BC
    */
   public
 
static
 
void
 clobInsert(String infile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 插入一个空的CLOB对象 */
           stmt.executeUpdate("INSERT INTO TEST_CLOB VALUES ('111', EMPTY_CLOB())"
);
           /* 查询此CLOB对象并锁定 */
           ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID='111' FOR UPDATE"
);
           while
 (rs.next()) {
               /* 取出此CLOB对象 */
               oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL"
);
               /* 向CLOB对象中写入数据 */
               BufferedWriter out = new
 BufferedWriter(clob.getCharacterOutputStream());
               BufferedReader in = new
 BufferedReader(
new
 FileReader(infile));
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               in.close();
               out.close();
           }
           /* 正式提交 */
           conn.commit();
       } catch
 (Exception ex) {
           /* 出错回滚 */
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * 修改CLOB对象（是在原CLOB对象基础上进行覆盖式的修改）
    *
    * @param infile - 数据文件
    * @throws java.lang.Exception
    * @roseuid 3EDA04B60367
    */
   public
 
static
 
void
 clobModify(String infile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 查询CLOB对象并锁定 */
           ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID='111' FOR UPDATE"
);
           while
 (rs.next()) {
               /* 获取此CLOB对象 */
               oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL"
);
               /* 进行覆盖式修改 */
               BufferedWriter out = new
 BufferedWriter(clob.getCharacterOutputStream());
               BufferedReader in = new
 BufferedReader(
new
 FileReader(infile));
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               in.close();
               out.close();
           }
           /* 正式提交 */
           conn.commit();
       } catch
 (Exception ex) {
           /* 出错回滚 */
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * 替换CLOB对象（将原CLOB对象清除，换成一个全新的CLOB对象）
    *
    * @param infile - 数据文件
    * @throws java.lang.Exception
    * @roseuid 3EDA04BF01E1
    */
   public
 
static
 
void
 clobReplace(String infile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 清空原CLOB对象 */
           stmt.executeUpdate("UPDATE TEST_CLOB SET CLOBCOL=EMPTY_CLOB() WHERE ID='111'"
);
           /* 查询CLOB对象并锁定 */
           ResultSet rs = stmt.executeQuery("SELECT CLOBCOL FROM TEST_CLOB WHERE ID='111' FOR UPDATE"
);
           while
 (rs.next()) {
               /* 获取此CLOB对象 */
               oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL"
);
               /* 更新数据 */
               BufferedWriter out = new
 BufferedWriter(clob.getCharacterOutputStream());
               BufferedReader in = new
 BufferedReader(
new
 FileReader(infile));
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               in.close();
               out.close();
           }
           /* 正式提交 */
           conn.commit();
       } catch
 (Exception ex) {
           /* 出错回滚 */
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * CLOB对象读取
    *
    * @param outfile - 输出文件名
    * @throws java.lang.Exception
    * @roseuid 3EDA04D80116
    */
   public
 
static
 
void
 clobRead(String outfile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 查询CLOB对象 */
           ResultSet rs = stmt.executeQuery("SELECT * FROM TEST_CLOB WHERE ID='111'"
);
           while
 (rs.next()) {
               /* 获取CLOB对象 */
               oracle.sql.CLOB clob = (oracle.sql.CLOB)rs.getClob("CLOBCOL"
);
               /* 以字符形式输出 */
               BufferedReader in = new
 BufferedReader(clob.getCharacterStream());
               BufferedWriter out = new
 BufferedWriter(
new
 FileWriter(outfile));
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               out.close();
               in.close();
           }
       } catch
 (Exception ex) {
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * 向数据库中插入一个新的BLOB对象
    *
    * @param infile - 数据文件
    * @throws java.lang.Exception
    * @roseuid 3EDA04E300F6
    */
   public
 
static
 
void
 blobInsert(String infile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 插入一个空的BLOB对象 */
           stmt.executeUpdate("INSERT INTO TEST_BLOB VALUES ('222', EMPTY_BLOB())"
);
           /* 查询此BLOB对象并锁定 */
           ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID='222' FOR UPDATE"
);
           while
 (rs.next()) {
               /* 取出此BLOB对象 */
               oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL"
);
               /* 向BLOB对象中写入数据 */
               BufferedOutputStream out = new
 BufferedOutputStream(blob.getBinaryOutputStream());
               BufferedInputStream in = new
 BufferedInputStream(
new
 FileInputStream(infile));
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               in.close();
               out.close();
           }
           /* 正式提交 */
           conn.commit();
       } catch
 (Exception ex) {
           /* 出错回滚 */
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * 修改BLOB对象（是在原BLOB对象基础上进行覆盖式的修改）
    *
    * @param infile - 数据文件
    * @throws java.lang.Exception
    * @roseuid 3EDA04E90106
    */
   public
 
static
 
void
 blobModify(String infile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 查询BLOB对象并锁定 */
           ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID='222' FOR UPDATE"
);
           while
 (rs.next()) {
               /* 取出此BLOB对象 */
               oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL"
);
               /* 向BLOB对象中写入数据 */
               BufferedOutputStream out = new
 BufferedOutputStream(blob.getBinaryOutputStream());
               BufferedInputStream in = new
 BufferedInputStream(
new
 FileInputStream(infile));
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               in.close();
               out.close();
           }
           /* 正式提交 */
           conn.commit();
       } catch
 (Exception ex) {
           /* 出错回滚 */
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * 替换BLOB对象（将原BLOB对象清除，换成一个全新的BLOB对象）
    *
    * @param infile - 数据文件
    * @throws java.lang.Exception
    * @roseuid 3EDA0505000C
    */
   public
 
static
 
void
 blobReplace(String infile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 清空原BLOB对象 */
           stmt.executeUpdate("UPDATE TEST_BLOB SET BLOBCOL=EMPTY_BLOB() WHERE ID='222'"
);
           /* 查询此BLOB对象并锁定 */
           ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID='222' FOR UPDATE"
);
           while
 (rs.next()) {
               /* 取出此BLOB对象 */
               oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL"
);
               /* 向BLOB对象中写入数据 */
               BufferedOutputStream out = new
 BufferedOutputStream(blob.getBinaryOutputStream());
               BufferedInputStream in = new
 BufferedInputStream(
new
 FileInputStream(infile));
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               in.close();
               out.close();
           }
           /* 正式提交 */
           conn.commit();
       } catch
 (Exception ex) {
           /* 出错回滚 */
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * BLOB对象读取
    *
    * @param outfile - 输出文件名
    * @throws java.lang.Exception
    * @roseuid 3EDA050B003B
    */
   public
 
static
 
void
 blobRead(String outfile) 
throws
 Exception
   {
       /* 设定不自动提交 */
       boolean
 defaultCommit = conn.getAutoCommit();
       conn.setAutoCommit(false
);

       try
 {
           /* 查询BLOB对象 */
           ResultSet rs = stmt.executeQuery("SELECT BLOBCOL FROM TEST_BLOB WHERE ID='222'"
);
           while
 (rs.next()) {
               /* 取出此BLOB对象 */
               oracle.sql.BLOB blob = (oracle.sql.BLOB)rs.getBlob("BLOBCOL"
);
               /* 以二进制形式输出 */
               BufferedOutputStream out = new
 BufferedOutputStream(
new
 FileOutputStream(outfile));
               BufferedInputStream in = new
 BufferedInputStream(blob.getBinaryStream());
               int
 c;
               while
 ((c=in.read())!=-
1
) {
                   out.write(c);
               }
               in.close();
               out.close();
           }
           /* 正式提交 */
           conn.commit();
       } catch
 (Exception ex) {
           /* 出错回滚 */
           conn.rollback();
           throw
 ex;
       }

       /* 恢复原提交状态 */
       conn.setAutoCommit(defaultCommit);
   }

   /**
    * 建立测试用表格
    * @throws Exception
    */
   public
 
static
 
void
 createTables() 
throws
 Exception {
       try
 {
           stmt.executeUpdate("CREATE TABLE TEST_CLOB ( ID NUMBER(3), CLOBCOL CLOB)"
);
           stmt.executeUpdate("CREATE TABLE TEST_BLOB ( ID NUMBER(3), BLOBCOL BLOB)"
);
       } catch
 (Exception ex) {

       }
   }

   /**
    * @param args - 命令行参数
    * @throws java.lang.Exception
    * @roseuid 3EDA052002AC
    */
   public
 
static
 
void
 main(String[] args) 
throws
 Exception
   {
       /* 装载驱动,建立数据库连接 */
       Class.forName(DRIVER);
       conn = DriverManager.getConnection(URL,USER,PASSWORD);
       stmt = conn.createStatement();

       /* 建立测试表格 */
       createTables();

       /* CLOB对象插入测试 */
       clobInsert("c:/clobInsert.txt"
);
       clobRead("c:/clobInsert.out"
);

       /* CLOB对象修改测试 */
       clobModify("c:/clobModify.txt"
);
       clobRead("c:/clobModify.out"
);

       /* CLOB对象替换测试 */
       clobReplace("c:/clobReplace.txt"
);   
</