// testClob.java
// 
// This class demonstrates inserting a new Clob value into an Oracle 8 database and
// updating an existing Clob value in the database.
//
// The test() method is a simple test that compares Clob values written to the database 
// to values read back.

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

class testClob
    {
    testClob(java.sql.Connection conn)
        {
        m_conn = conn;
        }
    // final int m_testlength = 0x100000;      // one meg
    int m_testlength = 1024* 3;      // 3k
    public void addData() throws SQLException
        {
        try
            {
            String idx;
            byte[] val= new byte[m_testlength];
            idx = String.valueOf(m_testlength);
            generateData(idx, val); // generate test data 

                                    // insert small (less then 4k string)
            java.sql.PreparedStatement stmt = 
                m_conn.prepareStatement("insert into TESTCLOB values(?, ?)");

            ByteArrayInputStream instr = new ByteArrayInputStream(val);

            stmt.setString(1, idx);
            stmt.setAsciiStream(2, instr, val.length);
            stmt.executeUpdate();

            // add large clob value
            m_testlength = 0x100000;      // one meg ( 1048576)
            val= new byte[m_testlength];
            idx = String.valueOf(m_testlength);
            generateData(idx, val); // generate test data 
            instr = new ByteArrayInputStream(val);
            stmt = 
                m_conn.prepareStatement("insert into TESTCLOB values(?, Empty_Clob())");
            stmt.setString(1, idx);
            stmt.executeUpdate();
            m_conn.commit();
            stmt.close();

            System.out.println("simulate an update on the new row");
            // simulate an update on the new row to see if the resulting lock is
            // strong enough for clob update
            stmt = m_conn.prepareStatement("update TESTCLOB set ind = '1048576' where ind = '1048576'");
            stmt.executeUpdate();
            System.out.println("row updated");
            // reselect the same row so we can update it
            java.sql.Statement select = m_conn.createStatement();
            // java.sql.ResultSet rs = select.executeQuery("select val from testclob where ind = '1048576' for update");
            java.sql.ResultSet rs = select.executeQuery("select val from testclob where ind = '1048576'");
            if(rs.next())       // should find the row
                {
                String strVal = new String(val);
                char[] arr = strVal.toCharArray();
                CharArrayReader rdr = new CharArrayReader(arr) ;
                rs.updateCharacterStream(1,rdr , m_testlength);
                System.out.println("about to call rs.updateRow()");
                rs.updateRow();
                System.out.println("rs.updateRow() returned");
                m_conn.commit();
                select.close();
                stmt.close();
                }         
            }
        catch (SQLException sch_ex) 
            {
            System.err.print ("SQLException: ");
            System.err.print (sch_ex.getMessage());
            }
        catch (Exception e) 
            {
            e.printStackTrace();
            }
        }
    
    public void createTable() throws SQLException
        {
        java.sql.Statement stmt = m_conn.createStatement();

        try
            {
            stmt.executeUpdate("drop table TESTCLOB");
            }
        catch (SQLException sch_ex) 
            {
            System.err.print ("SQLException: ");
            System.err.print (sch_ex.getMessage());
            }
        catch (Exception e) 
            {
            e.printStackTrace();
            }
        try
            {
            stmt.executeUpdate("create table TESTCLOB(ind varchar2(30), val clob)");
            }
        catch (SQLException sch_ex) 
            {
            System.err.print ("SQLException: ");
            System.err.print (sch_ex.getMessage());
            }
        catch (Exception e) 
            {
            e.printStackTrace();
            }
        }

    // generate test data 
    private void generateData(String indexkey, byte[] val)
        {
        int idx = 0;
        while(idx < m_testlength - 100)
            {
            val[idx++] = (byte)'0';       // add 10 characters values
            val[idx++] = (byte)'1';
            val[idx++] = (byte)'2';
            val[idx++] = (byte)'3';
            val[idx++] = (byte)'4';
            val[idx++] = (byte)'5';
            val[idx++] = (byte)'6';
            val[idx++] = (byte)'7';
            val[idx++] = (byte)'8';
            val[idx++] = (byte)'9';
            
            val[idx++] = (byte)' ';       // space
            }
        while(idx < m_testlength)
            val[idx++] = (byte)'x';
        }

    public void simple()
        {
        try
            {
            java.sql.Statement select = m_conn.createStatement();
            java.sql.ResultSet rs = select.executeQuery("select ind, val from testclob");
            // Class1.printHeaders(rs);
            while(rs.next())
                {
                String str = rs.getString(1);
                java.sql.Clob clb   = rs.getClob(2);
                long len = clb.length();
                String strSub = clb.getSubString(1, (int)len);
                System.out.println(str + ", len= " + len + ", value= " + strSub);
                }
            }
        catch (SQLException sch_ex) 
            {
            System.err.print ("SQLException: ");
            System.err.print (sch_ex.getMessage());
            }
        catch (Exception e) 
            {
            e.printStackTrace();
            }
        }

    public void test()
        {
        try
            {
            java.sql.Statement select = m_conn.createStatement();
            java.sql.ResultSet rs = select.executeQuery("select ind, val from testclob");
            // Class1.printHeaders(rs);
            while(rs.next())
                {
                String str = rs.getString(1);
                Integer len_val = new Integer(str);
                int len_shouldbe = len_val.intValue();
                java.sql.Clob clb   = rs.getClob(2);
                long len = clb.length();
                if(len != len_shouldbe)
                    {
                    System.out.println("clob test failure, len should of been " + str + " but was " + len);
                    }
                String strSub = clb.getSubString(1, (int)len);
                m_testlength = len_shouldbe;
                byte[] testval= new byte[m_testlength];
                generateData(str, testval); // generate test data 
                String strTestVal = new String(testval);
                if(strTestVal.length() != strSub.length())
                    {
                    System.out.println("clob test failure, actual length compare should of been " + strTestVal.length() + " but was " + strSub.length());
                    }

                int icmp = strSub.compareTo(strTestVal);
                if(  icmp == 0)
                    {
                    System.out.println("clob test succeeded for length = " + str);
                    }
                else
                    {
                    System.out.println("clob test failed for length = " + str);
                    }
                }
            }
        catch (SQLException sch_ex) 
            {
            System.err.print ("SQLException: ");
            System.err.print (sch_ex.getMessage());
            }
        catch (Exception e) 
            {
            e.printStackTrace();
            }
        }

    java.sql.Connection m_conn;
    }