详解jdbc实现对CLOB和BLOB数据类型的操作

//获得数据库连接      Connection con = ConnectionFactory.getConnection();      con.setAutoCommit(false);      Statement st = con.createStatement();      //不需要“for update”      ResultSet rs = st.executeQuery("select CLOBATTR from TESTCLOB where ID=1");      if (rs.next())      {        java.sql.Clob clob = rs.getClob("CLOBATTR");        Reader inStream = clob.getCharacterStream();        char[] c = new char[(int) clob.length()];        inStream.read(c);        //data是读出并需要返回的数据，类型是String        data = new String(c);        inStream.close();      }      inStream.close();      con.commit();      con.close();   

//获得数据库连接      Connection con = ConnectionFactory.getConnection();      con.setAutoCommit(false);      Statement st = con.createStatement();      //不需要“for update”      ResultSet rs = st.executeQuery("select BLOBATTR from TESTBLOB where ID=1");      if (rs.next())      {        java.sql.Blob blob = rs.getBlob("BLOBATTR");        InputStream inStream = blob.getBinaryStream();        //data是读出并需要返回的数据，类型是byte[]        data = new byte[input.available()];        inStream.read(data);        inStream.close();      }      inStream.close();      con.commit();      con.close();  

//获得数据库连接      Connection con = ConnectionFactory.getConnection();      con.setAutoCommit(false);      Statement st = con.createStatement();      //插入一个空对象empty_clob()      st.executeUpdate("insert into TESTCLOB (ID, NAME, CLOBATTR) values (1, "thename", empty_clob())");      //锁定数据行进行更新，注意“for update”语句      ResultSet rs = st.executeQuery("select CLOBATTR from TESTCLOB where ID=1 for update");      if (rs.next())      {        //得到java.sql.Clob对象后强制转换为oracle.sql.CLOB       oracle.sql.CLOB clob = (oracle.sql.CLOB) rs.getClob("CLOBATTR");        Writer outStream = clob.getCharacterOutputStream();        //data是传入的字符串，定义：String data        char[] c = data.toCharArray();        outStream.write(c, 0, c.length);      }      outStream.flush();      outStream.close();      con.commit();      con.close();    

//获得数据库连接      Connection con = ConnectionFactory.getConnection();      con.setAutoCommit(false);      Statement st = con.createStatement();      //插入一个空对象empty_blob()      st.executeUpdate("insert into TESTBLOB (ID, NAME, BLOBATTR) values (1, "thename", empty_blob())");      //锁定数据行进行更新，注意“for update”语句      ResultSet rs = st.executeQuery("select BLOBATTR from TESTBLOB where ID=1 for update");      if (rs.next())      {        //得到java.sql.Blob对象后强制转换为oracle.sql.BLOB       oracle.sql.BLOB blob = (oracle.sql.BLOB) rs.getBlob("BLOBATTR");        OutputStream outStream = blob.getBinaryOutputStream();        //data是传入的byte数组，定义：byte[] data       outStream.write(data, 0, data.length);      }      outStream.flush();      outStream.close();      con.commit();      con.close();    

# tnsnames.ora Network Configuration File: d:/oracle/product/10.2.0/client_1/NETWORK/ADMIN/tnsnames.ora   # Generated by Oracle configuration tools.    ORADB =     (DESCRIPTION =       (ADDRESS_LIST =         (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.100)(PORT = 1521))       )       (CONNECT_DATA =         (SID = ORCL)       )     )    MYORCL =     (DESCRIPTION =       (ADDRESS_LIST =         (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.100)(PORT = 1521))       )       (CONNECT_DATA =         (SERVICE_NAME = myorcl)       )     )  

create table TEST_ORALOB   (     ID     VARCHAR2(20),     TSBLOB BLOB not null,     TSCLOB CLOB not null   ) 

package lavasoft.oralob.common;   import oracle.sql.BLOB;   import java.io.*;  import java.sql.*;   /**   * JDBC读写Oracle10g的CLOB、BLOB   *   */  public class TestOraLob {        public static void main(String[] args) {           insertBlob();           queryBlob();       }        public static void insertBlob() {           Connection conn = DBToolkit.getConnection();           PreparedStatement ps = null;           try {               String sql = "insert into test_oralob (ID, TSBLOB, TSCLOB) values (?, ?, ?)";               ps = conn.prepareStatement(sql);               ps.setString(1, "100");               //设置二进制BLOB参数               File file_blob = new File("C://a.jpg");               InputStream in = new BufferedInputStream(new FileInputStream(file_blob));               ps.setBinaryStream(2, in, (int) file_blob.length());               //设置二进制CLOB参数               File file_clob = new File("c://a.txt");               InputStreamReader reader = new InputStreamReader(new FileInputStream(file_clob));               ps.setCharacterStream(3, reader, (int) file_clob.length());               ps.executeUpdate();               in.close();           } catch (IOException e) {               e.printStackTrace();           } catch (SQLException e) {               e.printStackTrace();           } finally {               DBToolkit.closeConnection(conn);           }       }        public static void queryBlob() {           Connection conn = DBToolkit.getConnection();           PreparedStatement ps = null;           Statement stmt = null;           ResultSet rs = null;           try {               String sql = "select TSBLOB from TEST_ORALOB where id ='100'";               stmt = conn.createStatement();               rs = stmt.executeQuery(sql);               if (rs.next()) {                   //读取Oracle的BLOB字段                   InputStream in = rs.getBinaryStream(1);                   File file = new File("c://a1.jpg");                   OutputStream out = new BufferedOutputStream(new FileOutputStream(file));                   byte[] buff1 = new byte[1024];                   for (int i = 0; (i = in.read(buff1)) > 0;) {                       out.write(buff1, 0, i);                   }                   out.flush();                   out.close();                   in.close();                   //读取Oracle的CLOB字段                   char[] buff2 = new char[1024];                   File file_clob = new File("c://a1.txt");                   OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(file_clob));                   Reader reader = rs.getCharacterStream(1);                   for (int i = 0; (i = reader.read(buff2)) > 0;) {                       writer.write(buff2, 0, i);                   }                   writer.flush();                   writer.close();                   reader.close();               }               rs.close();               stmt.close();           } catch (IOException e) {               e.printStackTrace();           } catch (SQLException e) {               e.printStackTrace();           } finally {               DBToolkit.closeConnection(conn);           }       }   } 

//设置二进制CLOB参数    String xxx = "abcdefg";   ps.setCharacterStream(3, new StringReader(xxx), xxx.getBytes("GBK").length);    ps.executeUpdate();    in.close();