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

Fields

Modifier and Type	Field and Description
static String	USE_UNIQUE_TABLE_NAMES Property name which indicates unique table names should be generated.

Method Summary

Methods

Modifier and Type	Method and Description
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.