lobpros.java

java读取CLOB

//Source file: C:\\Rose2Java\\zhsoft\\test\\LobPros.java

package zhsoft.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
 *
 * @author 雨亦奇([e-mail])
 * @version 1.0
 * @since 2003.05.28
 */
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");
       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);
   }
}