ColumnSizes Class

DEPRECATED

com.bea.p13n.content.document.ref.loader
ColumnSizes Class

public class ColumnSizes

    extends Object

Utility class to help determine JDBC table column sizes and to truncate data for inserting.

The general usage of this class should be truncate data fields before sending them to the database to avoid extraneous errors when data truncation would be a valid solution. For example,

 String id = request.getParameter("id");
 String name = request.getParameter("name");
 String value = request.getParameter("value");
 Connection con =
     DriverManager.getConnection("jdbc:weblogic:jts:commercePool");
 String sql = "INSERT INTO MYTABLE (ID, NAME, VALUE) VALUES (?, ?, ?)";
 PreparedStatement stmt = con.prepareStatment(sql);
 id = ColumnSizes.truncate(id, con, "MYTABLE", "ID");
 stmt.setString(1, id);
 name = ColumnSizes.truncate(name, con, "MYTABLE", "NAME");
 stmt.setString(2, name);
 value = ColumnSizes.truncate(value, con, "MYTABLE", "VALUE");
 stmt.setString(3, value);
 stmt.executeUpdate();
 stmt.close();
 con.close();
 

Additionally, you can use the getColumnInfo() method to determine the size of a table column. In this manner, you could warn the user about the max size or about data truncation.
When determining the size of columns, the following logic is used:

  1. If the property "p13n.jdbc.maxsize.<table>.<column>" in the loader.properties file is set to a numeric value, then it is assumed the column is a TEXT column with that maximum length.
  2. If the property "p13n.jdbc.maxsize.checkMetaData" in the loader.properties file is set to "true" and the specified Connection is not null, then the Connection's DatabaseMetaData will be used to determine the column information.
  3. If the column is not found or "p13n.jdbc.maxsize.checkMetaData" is not "true", then null is returned.
Additionally, the column information is cached to avoid extraneous database activity. Therefore, if the tables in the database are altered, the server will need to be restarted.

Note: Setting p13n.jdbc.maxsize.checkMetaData to true will cause the java.sql.DatabaseMetaData.getColumns() method to be invoked. Some JDBC drivers do not support this method correctly. Some Type 2 drivers might core dump on this method call.


Hierarchy
Object
  ColumnSizes

Nested Class Summary

public static classcom.bea.p13n.content.document.ref.loader.ColumnSizes.ColumnInfo
           Object describing a column.

Field Summary

public static final int
BOOLEAN
The constant for a boolean type (0).
public static boolean
CHECK_META_DATA
Should we check with the DatabaseMetaData for getting column sizes.
public static final int
DATETIME
The constant for a datetime type (4).
public static final int
FLOAT
The constant for the floating-point numeric type (2).
public static final int
INTEGER
The constant for a numeric type (1).
public static final int
MULTI_VALUED
The constant for a multivalued type (6).
public static final int
TEXT
The constant for a text type (3).
public static final int
USER_DEFINED
The constant for a user defined type (5).
 

Constructor Summary

ColumnSizes()

 

Method Summary

public static int
fromSQLType(int sqlType)
Convert a java.sql.Types constant into one of ours.
public static ColumnSizes.ColumnInfo
getColumnInfo(Connection con, String table, String column)
Get the ColumnInfo for the specified column.
public static String
getTypeName(int type)
Get the default descriptive type name.
public static Object
truncate(Object in, Connection con, String table, String column)
Truncate the specified object to the size of the specified table/column.
public static String
truncate(String in, Connection con, String table, String column)
Truncate the specified String to the size of the specified table/column.
 
Methods from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
   

Field Detail

BOOLEAN

public static final int BOOLEAN
The constant for a boolean type (0).


CHECK_META_DATA

public static boolean CHECK_META_DATA
Should we check with the DatabaseMetaData for getting column sizes.

This is initialized from the "p13n.jdbc.maxsize.checkMetaData" property in the weblogiccommerce.properties.


DATETIME

public static final int DATETIME
The constant for a datetime type (4).


FLOAT

public static final int FLOAT
The constant for the floating-point numeric type (2).


INTEGER

public static final int INTEGER
The constant for a numeric type (1).


MULTI_VALUED

public static final int MULTI_VALUED
The constant for a multivalued type (6).


TEXT

public static final int TEXT
The constant for a text type (3).


USER_DEFINED

public static final int USER_DEFINED
The constant for a user defined type (5).

 

Constructor Detail

ColumnSizes

public ColumnSizes()
 

Method Detail

fromSQLType(int) Method

public static int fromSQLType(int sqlType)
Convert a java.sql.Types constant into one of ours.

Parameters

sqlType
value from java.sql.Types.

Returns

the corresponding attribute type (BOOLEAN, NUMERIC, TEXT, DATETIME, MULTI_VALUED, or USER_DEFINED).

getColumnInfo(Connection, String, String) Method

public static ColumnSizes.ColumnInfo getColumnInfo(Connection con, 
                                                   String table, 
                                                   String column)
throws SQLException
Get the ColumnInfo for the specified column.

If the column information is not found in the cache, it will be loaded (see class comments for details on how it is loaded).

Parameters

con
the connection to use, null to not.
table
the table name.
column
the column name.

Returns

the ColumnInfo or null if the column doesn't exist.

Exceptions

SQLException
if the information cannot be loaded.

getTypeName(int) Method

public static String getTypeName(int type)
Get the default descriptive type name.


truncate(Object, Connection, String, String) Method

public static Object truncate(Object in, 
                              Connection con, 
                              String table, 
                              String column)
Truncate the specified object to the size of the specified table/column.


truncate(String, Connection, String, String) Method

public static String truncate(String in, 
                              Connection con, 
                              String table, 
                              String column)
Truncate the specified String to the size of the specified table/column.

Related Topics

ColumnSizes.truncate(Object, Connection, String, String)