com.sun.jdo.spi.persistence.generator.database
Class MappingPolicy

java.lang.Object
  com.sun.jdo.spi.persistence.generator.database.MappingPolicy

All Implemented Interfaces:

Cloneable

public class MappingPolicy
extends Object
implements Cloneable

Describes how Java classes and their fields are to be mapped to database tables and columns

Field Summary

static String

USE_UNIQUE_TABLE_NAMES Property name which indicates unique table names should be generated.

Method Summary

protected Object	clone() Clones the vendor-specific policy for generator session.
String	getColumnName(String className, String fieldName, String tableName) Returns the name of a column for a given field in a given class.
String	getConstraintColumnName(String tableName, String columnName) Returns the name of the column which represents a foreign key in the named table.
String	getConstraintName(String relName, String uniqueId) Returns the name of a constraint corresponding to the named relationship.
com.sun.jdo.spi.persistence.generator.database.JDBCInfo	getJDBCInfo(String fieldName, String fieldType) Returns JDBC type information corresponding to the given field name and type.
static String	getJdbcTypeName(int type) Provide the String name of a JDBC type, as per java.sql.Types.
String	getJoinTableName(String className1, String className2) Returns the name of a join table which joins the tables that correspond to the two named classes.
static MappingPolicy	getMappingPolicy(String databaseType) Returns a vendor-specifc MappingPolicy instance.
static String	getOverrideForLength(String className, String fieldName) Provides a String that can be recognized as a policy to override the default length of a field.
static String	getOverrideForNullability(String className, String fieldName) Provides a String that can be recognized as a policy to override the default nullability of a field.
static String	getOverrideForPrecision(String className, String fieldName) Provides a String that can be recognized as a policy to override the default precision of a field.
static String	getOverrideForScale(String className, String fieldName) Provides a String that can be recognized as a policy to override the default scale of a field.
static String	getOverrideForType(String className, String fieldName) Provides a String that can be recognized as a policy to override the default type of a field.
String	getPrimaryKeyConstraintName(String tableName) Returns the name of a PK constraint, unique-ified as required.
String	getSQLTypeName(int jdbcType) Returns the String name of the SQL type for a given JDBC type.
String	getTableName(String name, String uniqueName) Returns the name of a table for a given class, as per current policy.
void	setUniqueTableName(boolean uniqueTableName) Sets whether or not unique table names should be generated.
void	setUserPolicy(Properties props) Sets user-provided policy to that provided in the given properties.
String	toString() Debug support.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

USE_UNIQUE_TABLE_NAMES

public static final String USE_UNIQUE_TABLE_NAMES

Property name which indicates unique table names should be generated.

See Also:

Constant Field Values

Method Detail

getMappingPolicy

public static MappingPolicy getMappingPolicy(String databaseType)
                                      throws IOException

Returns a vendor-specifc MappingPolicy instance. This method always returns a copy (clone) of the known MappingPolicy to allow for user-specific overrides.

Parameters:

databaseType - a database vendor name as a String.

Returns:

MappingPolicy instance corresponding to the provided database vendor name.

Throws:

IOException - if there are problems reading the vendor- specific mappinng policy file

clone

protected Object clone()
                throws CloneNotSupportedException

Clones the vendor-specific policy for generator session. Replace the namespaces map in the clone, so that each instance has its own.

Overrides:

clone in class Object

Returns:

clone of this MappingPolicy

Throws:

CloneNotSupportedException - never thrown

setUserPolicy

public void setUserPolicy(Properties props)

Sets user-provided policy to that provided in the given properties.

Parameters:

props - Properties which override built in defaults.

setUniqueTableName

public void setUniqueTableName(boolean uniqueTableName)

Sets whether or not unique table names should be generated.

Parameters:

uniqueTableName - If true, tables names will be unique.

getSQLTypeName

public String getSQLTypeName(int jdbcType)

Returns the String name of the SQL type for a given JDBC type.

Parameters:

jdbcType - One of the values from java.sql.Types.

Returns:

Name of SQL type corresponding to given jdbcType.

getJDBCInfo

public com.sun.jdo.spi.persistence.generator.database.JDBCInfo getJDBCInfo(String fieldName,
                                                                           String fieldType)

Returns JDBC type information corresponding to the given field name and type. If fieldName is null or there is no fieldName - specific information already existing, the default for the given fieldType is returned. Otherwise, information specific to the fieldName is returned. Note: It is possible to have a field in a class have the same name as another class; this mechanism is not robust in that case:

 class Foo { }

 class MyFoo {
     Foo Foo = new Foo();
 }
 

We think this obfuscation unlikely to occur.

Parameters:

fieldName - Name of field for which information is needed. May be null, in which case only fieldType is used to determine returned information.

fieldType - Name of a Java type.

Returns:

JDBCInfo representing the field or type.

getOverrideForLength

public static String getOverrideForLength(String className,
                                          String fieldName)

Provides a String that can be recognized as a policy to override the default length of a field.

Parameters:

className - name of a class

fieldName - name of a field in that class

Returns:

a String that can be used as the name of a length override for a field in a class.

getOverrideForNullability

public static String getOverrideForNullability(String className,
                                               String fieldName)

Provides a String that can be recognized as a policy to override the default nullability of a field.

Parameters:

className - name of a class

fieldName - name of a field in that class

Returns:

a String that can be used as the name of a nullability override for a field in a class.

getOverrideForPrecision

public static String getOverrideForPrecision(String className,
                                             String fieldName)

Provides a String that can be recognized as a policy to override the default precision of a field.

Parameters:

className - name of a class

fieldName - name of a field in that class

Returns:

a String that can be used as the name of a precision override for a field in a class.

getOverrideForScale

public static String getOverrideForScale(String className,
                                         String fieldName)

Provides a String that can be recognized as a policy to override the default scale of a field.

Parameters:

className - name of a class

fieldName - name of a field in that class

Returns:

a String that can be used as the name of a scale override for a field in a class.

getOverrideForType

public static String getOverrideForType(String className,
                                        String fieldName)

Provides a String that can be recognized as a policy to override the default type of a field.

Parameters:

className - name of a class

fieldName - name of a field in that class

Returns:

a String that can be used as the name of a type override for a field in a class.

getJdbcTypeName

public static String getJdbcTypeName(int type)
                              throws IllegalArgumentException

Provide the String name of a JDBC type, as per java.sql.Types.

Parameters:

type - A value from java.sql.Types

Returns:

the String name corresponding to type

Throws:

IllegalArgumentException - if type is not recognized as being a valid member of java.sql.Types. Note that only a subset of the types in java.sql.Types are recognized.

getTableName

public String getTableName(String name,
                           String uniqueName)

Returns the name of a table for a given class, as per current policy.

Parameters:

name - Basis for what the returned table should be named, for example the unqualified name of a class.

uniqueName - Used if the current policy is to return a unique name. Client must provide a name that is unique to them.

Returns:

Name to be used for table. Regardless of the current policy, the name is different from other names returned during the current run of DatabaseGenerator.generate(com.sun.jdo.api.persistence.model.Model, java.util.List, com.sun.jdo.spi.persistence.generator.database.MappingPolicy, java.lang.String, java.lang.String, boolean).

getColumnName

public String getColumnName(String className,
                            String fieldName,
                            String tableName)

Returns the name of a column for a given field in a given class. The column name will be unique within the table.

Parameters:

className - Name of the class containing the field.

fieldName - Name of the field for which a column name is returned.

tableName - Name of the table in which the column name is created.

Returns:

Name of a column that is unique within the named table.

getConstraintColumnName

public String getConstraintColumnName(String tableName,
                                      String columnName)

Returns the name of the column which represents a foreign key in the named table.

Parameters:

tableName - Name of the table in which the FK column will be created.

columnName - Name of PK column in referenced table.

Returns:

Name of the FK column in the named table.

getConstraintName

public String getConstraintName(String relName,
                                String uniqueId)

Returns the name of a constraint corresponding to the named relationship.

Parameters:

relName - Name of a relationship.

uniqueId - Id that can be appened to relName to distinguish it from other relNames in the database. Will be appended only if uniqueTableName is true.

Returns:

Name of a constraint.

getPrimaryKeyConstraintName

public String getPrimaryKeyConstraintName(String tableName)

Returns the name of a PK constraint, unique-ified as required.

Parameters:

tableName - Name of a table on which a constraint is to be placed.

Returns:

Name of a constraint on named table.

getJoinTableName

public String getJoinTableName(String className1,
                               String className2)

Returns the name of a join table which joins the tables that correspond to the two named classes.

Parameters:

className1 - Name of one class to join.

className2 - Name of the other class to join.

Returns:

Name of a join table.

toString

public String toString()

Debug support.

Overrides:

toString in class Object

Returns:

A description of this MappingPolicy in string form. Basically, all it's "interesting" values.