www.pudn.com > town-1[1].0.4.rar > Column.java
package com.workingdogs.town;
import java.io.*;
/*
Town, a Java JDBC abstraction layer
Copyright (C) 1999 Serge Knystautas, Jon Stevens
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
import java.sql.*;
/**
This class represents a Column in the database and its associated meta information.
A Record is a collection of columns.
@author Jon S. Stevens jon@working-dogs.com
@author Serge Knystautas sergek@lokitech.com
@version 1.0
*/
public class Column
{
/** column number in a schema object */
private int columnNumber = -1;
/** name of the column */
private String name = "";
/** example: this column is of type "String" */
private String columnTypeName = "";
/** what java.sql.Type is this column? */
private int columnType = -1;
/** name of table that this column belongs to */
private String tableName = "";
/** is null allowed for this column? */
private boolean nullAllowed = false;
/** is this an auto increment column? */
private boolean autoIncrement = false;
/** is this a read only column? */
private boolean readOnly = false;
/** is this a searchable column? */
private boolean searchable = false;
/** what is the scale of this column? */
private int scale = -1;
/** what is the precision of this column? */
private int precision = -1;
/** what is the length of this column? */
private int length = -1;
/** the column type resolved internally */
private String type = "";
/** Constructor */
public Column()
{
this.columnNumber = -1;
this.name = "";
this.columnTypeName = "";
this.tableName = "";
this.columnType = -1;
this.nullAllowed = false;
this.autoIncrement = false;
this.readOnly = false;
this.searchable = false;
this.scale = -1;
this.precision = -1;
this.length = -1;
this.type = "";
}
/**
does this column auto increment?
@returns whether or not this column auto increments
*/
public boolean autoIncrement()
{
return this.autoIncrement;
}
/**
the data type of a column
@returns the java.sql.Types String
*/
public String dbType()
{
return this.columnTypeName;
}
/** column isBigDecimal: Types.NUMERIC || Types.DECIMAL */
public boolean isBigDecimal()
{
if (this.typeEnum() == Types.NUMERIC || this.typeEnum() == Types.DECIMAL)
return true;
else
return false;
}
/** column isBinary: Types.BINARY */
public boolean isBinary()
{
if (this.typeEnum() == Types.BINARY)
return true;
else
return false;
}
/** column isBoolean: Types.BIT */
public boolean isBoolean()
{
if (this.typeEnum() == Types.BIT)
return true;
else
return false;
}
/** column isByte: Types.TINYINT */
public boolean isByte()
{
if (this.typeEnum() == Types.TINYINT)
return true;
else
return false;
}
/** column isBytes: Types.BINARY || Types.VARBINARY || Types.LONGVARBINARY */
public boolean isBytes()
{
if (this.typeEnum() == Types.LONGVARBINARY || this.typeEnum() == Types.VARBINARY ||
this.columnType == Types.BINARY)
return true;
else
return false;
}
/** column isDate: Types.Date */
public boolean isDate()
{
if (this.typeEnum() == Types.DATE)
return true;
else
return false;
}
/** column isDouble: Types.FLOAT || Types.DOUBLE */
public boolean isDouble()
{
if (this.typeEnum() == Types.FLOAT || this.typeEnum() == Types.DOUBLE)
return true;
else
return false;
}
/** column isFloat: Types.REAL */
public boolean isFloat()
{
if (this.typeEnum() == Types.REAL)
return true;
else
return false;
}
/** column isInt: Types.INTEGER */
public boolean isInt()
{
if (this.typeEnum() == Types.INTEGER)
return true;
else
return false;
}
/** column isLong: Types.BIGINT */
public boolean isLong()
{
if (this.typeEnum() == Types.BIGINT)
return true;
else
return false;
}
/** column isLongVarBinary: Types.LONGVARBINARY */
public boolean isLongVarBinary()
{
if (this.typeEnum() == Types.LONGVARBINARY)
return true;
else
return false;
}
/** column isShort: Types.SMALLINT */
public boolean isShort()
{
if (this.typeEnum() == Types.SMALLINT)
return true;
else
return false;
}
/** column isString: Types.LONGVARCHAR || -11 || Types.VARCHAR */
public boolean isString()
{
if (this.typeEnum() == Types.LONGVARCHAR || this.typeEnum() == 11 ||
this.typeEnum() == Types.VARCHAR)
return true;
else
return false;
}
/** column isTime: Types.TIME */
public boolean isTime()
{
if (this.typeEnum() == Types.TIME)
return true;
else
return false;
}
/** column isTimestamp: Types.TIMESTAMP */
public boolean isTimestamp()
{
if (this.typeEnum() == Types.TIMESTAMP)
return true;
else
return false;
}
/** column isVarBinary: Types.VARBINARY */
public boolean isVarBinary()
{
if (this.typeEnum() == Types.VARBINARY)
return true;
else
return false;
}
/** unknown use */
public String javaType() throws DataSetException
{
throw new DataSetException ("Method not implemented: Unknown use!");
}
/**
the storage length of a column
@returns the storage length of a column
*/
public int length()
{
return this.length;
}
/**
the name of the column
@retuns the name of the column
*/
public String name()
{
return this.name;
}
/**
does this column allow null?
@returns whether or not the column has null Allowed
*/
public boolean nullAllowed()
{
return this.nullAllowed;
}
/** internal package method for populating a Column instance */
void populate (ResultSetMetaData rsmd,
int colNum) throws ConnectionException
{
try
{
this.columnNumber = colNum;
this.name = rsmd.getColumnName (columnNumber);
this.tableName = rsmd.getTableName(columnNumber);
this.columnTypeName = rsmd.getColumnTypeName (columnNumber);
this.columnType = rsmd.getColumnType (columnNumber);
this.nullAllowed = rsmd.isNullable(columnNumber) == 1;
this.autoIncrement = rsmd.isAutoIncrement(columnNumber);
this.readOnly = rsmd.isReadOnly (columnNumber);
this.searchable = rsmd.isSearchable (columnNumber);
this.scale = rsmd.getScale (columnNumber);
this.precision = rsmd.getPrecision (columnNumber);
this.length = rsmd.getColumnDisplaySize (columnNumber);
}
catch (SQLException sqle)
{
throw new ConnectionException (sqle);
}
}
/**
the precision of the column
@returns the precision of the column
*/
public int precision()
{
return this.precision;
}
/**
is this column read only?
@returns whether or not this column is read only
*/
public boolean readOnly()
{
return this.readOnly;
}
/**
the scale of the column
@returns the scale of the column
*/
public int scale()
{
return this.scale;
}
/**
is this column searchable?
@returns true if this column is searchable
*/
public boolean searchable()
{
return this.searchable;
}
/**
the type of the column as a string
@returns the type of the column as a string
*/
public String type()
{
if (isBoolean())
return "BOOLEAN";
else if (isByte())
return "BYTE";
else if (isShort())
return "SHORT";
else if (isInt())
return "INTEGER";
else if (isLong())
return "LONG";
else if (isFloat())
return "FLOAT";
else if (isDouble())
return "DOUBLE";
else if (isBigDecimal())
return "BIGDECIMAL";
else if (isDate())
return "DATE";
else if (isTime())
return "TIME";
else if (isTimestamp())
return "TIMESTAMP";
else if (isString())
return "STRING";
else if (isBinary())
return "BINARY";
else if (isVarBinary())
return "VARBINARY";
else if (isLongVarBinary())
return "LONGVARBINARY";
return "UNKNOWN TYPE: " + typeEnum();
}
/**
the data type of a column
@returns the java.sql.Types enum
*/
public int typeEnum()
{
return this.columnType;
}
}