JDBC存取ORACLE大型数据对象LOB几种情况的示范类

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

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:@test2000:1521:orac";

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

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

  /**
  * 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");
    clobRead("c:/clobReplace.out");

    /* BLOB对象插入测试 */
    blobInsert("c:/blobInsert.doc");
    blobRead("c:/blobInsert.out");

    /* BLOB对象修改测试 */
    blobModify("c:/blobModify.doc");
    blobRead("c:/blobModify.out");

    /* BLOB对象替换测试 */
    blobReplace("c:/blobReplace.doc");
    blobRead("c:/bolbReplace.out");

    /* 关闭资源退出 */
    conn.close();
    System.exit(0);
  }
}

 

原文：http://boardlayout.blog.ccidnet.com/blog-htm-itemid-122701-do-showone-type-blog-uid-43437.html