columns.java

Java写的TDS协议(JDBC/ODBC)实现

//
// Copyright 1998 CDS Networks, Inc., Medford Oregon
//
// All rights reserved.
//
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// modification, are permitted provided that the following conditions are met:
// 1. Redistributions of source code must retain the above copyright
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// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. All advertising materials mentioning features or use of this software
//    must display the following acknowledgement:
//      This product includes software developed by CDS Networks, Inc.
// 4. The name of CDS Networks, Inc.  may not be used to endorse or promote
//    products derived from this software without specific prior
//    written permission.
//
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL CDS NETWORKS, INC. BE LIABLE
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package net.sourceforge.jtds.jdbc;

import java.util.Vector;
import java.sql.*;

/**
 * Information about the columns in a result set.
 *
 * @author   Craig Spannring
 * @created  17 March 2001
 */
public class Columns
{
    public final static String cvsVersion = "$Id: Columns.java,v 1.1 2002/10/14 10:48:59 alin_sinpalean Exp $";

    private Vector columns = null;
    /**
     * Real column count. Number of columns actually returned by the server.
     */
    private int columnCount = 0;
    /**
     * Fake column count. Number of columns visible to the user. Used for
     * hiding columns returned by <code>DatabaseMetaData</code> methods.
     */
    private int fakeColCount = 0;

    public Columns()
    {
        this(10);
    }

    public Columns(int size)
    {
        columns = new Vector(size);
    }

    public void setCatalog(int columnNumber, String value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setCatalog(value);
    }

    public void setSchema(int columnNumber, String value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setSchema(value);
    }

    public void setName(int columnNumber, String value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setName(value);
    }

    public void setDisplaySize(int columnNumber, int value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setDisplaySize(value);
    }

    public void setBufferSize(int columnNumber, int value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setBufferSize(value);
    }

    public void setLabel(int columnNumber, String value)
    {
        ((Column)columns.elementAt(columnNumber-1)).setLabel(value);
    }

    public void setNativeType(int columnNumber, int value)
    {
        // remeber that this is the native type
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setType(value);
    }

    public void setPrecision(int columnNumber, int value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setPrecision(value);
    }

    public void setScale(int columnNumber, int value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setScale(value);
    }

    public void setAutoIncrement(int columnNumber, boolean value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setAutoIncrement(value);
    }

    public void setNullable(int columnNumber, int value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setNullable(value);
    }

    public void setReadOnly(int columnNumber, boolean value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setReadOnly(value);
    }

    public void setCaseSensitive(int columnNumber, boolean value)
    {
        resize(columnNumber);
        ((Column)columns.elementAt(columnNumber-1)).setCaseSensitive(value);
    }

    public void setJdbcType(int columnNumber, int jdbcType) throws SQLException
    {
        try
        {
            setNativeType(columnNumber, Tds.cvtJdbcTypeToNativeType(jdbcType));
        }
        catch( TdsException e )
        {
            throw new SQLException("TDS error- " + e.getMessage());
        }
    }

    public void setTableName(int columnNumber, String tableName)
    {
        resize(columnNumber);
        ((Column) columns.elementAt(columnNumber - 1)).setTableName(tableName);
    }

    public Column getColumn(int columnNumber)
    {
        resize(columnNumber);
        return (Column)columns.elementAt(columnNumber - 1);
    }

    /**
     *@return    The ColumnCount value
     */
    public int realColumnCount()
    {
        return columnCount;
    }

    public int fakeColumnCount()
    {
        return fakeColCount;
    }

    public void setFakeColumnCount(int count)
    {
        fakeColCount = count;
    }

    public String getCatalog(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getCatalog();
    }

    public String getSchema(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getSchema();
    }

    public String getName(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getName();
    }


    public int getDisplaySize(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getDisplaySize();
    }


    public int getBufferSize(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getBufferSize();
    }


    public String getLabel(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getLabel();
    }


    public int getNativeType(int columnNumber)
    {
        // remeber that this is the native type
        return ((Column) columns.elementAt(columnNumber - 1)).getType();
    }



    public int getJdbcType(int index)
             throws SQLException
    {
        try {
            return Tds.cvtNativeTypeToJdbcType(getNativeType(index), getBufferSize(index));
        }
        catch (TdsException e) {
            throw new SQLException("TDS error- " + e.getMessage());
        }
    }


    public int getPrecision(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getPrecision();
    }


    public int getScale(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getScale();
    }


    public Boolean isAutoIncrement(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).isAutoIncrement();
    }

    public int isNullable(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).isNullable();
    }

    public Boolean isReadOnly(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).isReadOnly();
    }

    public Boolean isCaseSensitive(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).isCaseSensitive();
    }

    public String getTableName(int columnNumber)
    {
        return ((Column) columns.elementAt(columnNumber - 1)).getTableName();
    }

    /**
     *  merge the data from two instances of Columns. The 4.2 TDS protocol gives
     *  the column information in multiple pieces. Each piece gives us a
     *  specific piece of information for all the columns in the result set. We
     *  must join those pieces of information together to use as the basis for
     *  the ResultSetMetaData class.
     *
     *@param  other
     *@return <code>this</code> object
     *@exception  TdsException  thrown if the two instances of Columns can't be
     *      merged. This can happen if the number of columns isn't identical or
     *      if there is conflicting data.
     *@todo                     Description of Parameter
     *@todo                     Description of the Returned Value
     */
    public Columns merge(Columns other)
             throws TdsException
    {
        if( this.columnCount != other.columnCount )
            throw new TdsException("Confused. Mismatch in number of columns");

        for( int i=1; i<=columnCount; i++ )
        {
//            if( this.getCatalog(i) == null )
//                this.setCatalog(i, other.getCatalog(i));
//            else if( other.getCatalog(i) != null )
//                throw new TdsException("Trying to merge two non-null columns");
//
//            if( this.getSchema(i) == null )
//                this.setSchema(i, other.getSchema(i));
//            else if( other.getSchema(i) != null )
//                throw new TdsException("Trying to merge two non-null columns");

            if( this.getName(i) == null )
                this.setName(i, other.getName(i));
            else if( other.getName(i) != null )
                throw new TdsException("Trying to merge two non-null columns");

            if( this.getLabel(i) == null )
                this.setLabel(i, other.getLabel(i));
            else if( other.getLabel(i) != null )
                throw new TdsException("Trying to merge two non-null columns");

            if( this.getTableName(i) == null )
                this.setTableName(i, other.getTableName(i));
            else if( other.getTableName(i) != null )
                throw new TdsException("Trying to merge two non-null columns");

            if( this.getDisplaySize(i) == -1 )
                this.setDisplaySize(i, other.getDisplaySize(i));
            else if( other.getDisplaySize(i) != -1 )
                throw new TdsException("Trying to merge two non-null columns");

            if( this.getBufferSize(i) == -1 )
                this.setBufferSize(i, other.getBufferSize(i));
            else if( other.getBufferSize(i) != -1 )
                throw new TdsException("Trying to merge two non-null columns");

            if( this.getNativeType(i) == -1)
                this.setNativeType(i, other.getNativeType(i));
            else if( other.getNativeType(i) != -1 )
                throw new TdsException("Trying to merge two non-null columns");

            if( this.getPrecision(i) == -1 )
                this.setPrecision(i, other.getPrecision(i));
            else if( other.getPrecision(i) != -1 )
                throw new TdsException("Trying to merge two non-null columns");

            if( this.getScale(i) == -1 )
                this.setScale(i, other.getScale(i));
            else if( other.getScale(i) != -1 )
                throw new TdsException("Trying to merge two non-null columns");

            if( !this.readOnlyWasSet(i) )
                this.setReadOnly(i, other.isReadOnly(i).booleanValue());
            else if( other.readOnlyWasSet(i) )
                throw new TdsException("Trying to merge two non-null columns");

            if( !this.autoIncrementWasSet(i) )
                this.setAutoIncrement(i, other.isAutoIncrement(i).booleanValue());
            else if( other.autoIncrementWasSet(i) )
                throw new TdsException("Trying to merge two non-null columns");

            if( !this.caseSensitiveWasSet(i) )
                this.setCaseSensitive(i, other.isCaseSensitive(i).booleanValue());
            else if( other.caseSensitiveWasSet(i) )
                throw new TdsException("Trying to merge two non-null columns");

            if( !this.nullableWasSet(i) )
                this.setNullable(i, other.isNullable(i));
            else if( other.nullableWasSet(i) )
                throw new TdsException("Trying to merge two non-null columns");
        }
        return this;
    }

    public boolean autoIncrementWasSet(int columnNumber)
    {
        return ((Column) (columns.elementAt(columnNumber - 1))).isAutoIncrement() != null;
    }

    public boolean nullableWasSet(int columnNumber)
    {
        return (isNullable(columnNumber)
                 != java.sql.ResultSetMetaData.columnNullableUnknown);
    }

    public boolean readOnlyWasSet(int columnNumber)
    {
        return ((Column) (columns.elementAt(columnNumber - 1))).isReadOnly() != null;
    }

    public boolean caseSensitiveWasSet(int columnNumber)
    {
        return ((Column) (columns.elementAt(columnNumber - 1))).isCaseSensitive() != null;
    }

    /*
     * merge()
     */

    private void resize(int columnNumber)
    {
        if (columnNumber > columnCount) {
            columnCount = columnNumber;
            fakeColCount = columnNumber;
        }

        if (columns.size() <= columnNumber) {
            columns.setSize(columnNumber + 1);
        }

        if (columns.elementAt(columnNumber - 1) == null) {
            columns.setElementAt(new Column(), columnNumber - 1);
        }

    }

}