JPublisher and the Creation of Custom Java Classes

Oracle offers flexibility in how users can customize the mapping of Oracle object types, reference types, and collection types to Java classes in a strongly typed paradigm. Developers have the following choices in creating these custom Java classes:

• using Oracle JPublisher to automatically generate custom Java classes and using those classes directly without modification

• using JPublisher to automatically generate custom Java classes and subclassing them to create custom Java classes with added functionality

• manually coding custom Java classes without using JPublisher, provided that the classes meet the requirements stated in "Custom Java Class Requirements"

Although you have the option of manually coding your custom Java classes, using JPublisher is advisable. If you need special functionality, you can subclass a class that JPublisher generates or use it as a field in a class that you create.

This manual provides only a minimal level of information and detail regarding the JPublisher utility. See the Oracle8i JPublisher User's Guide for more information.

What JPublisher Produces

When you run JPublisher for a user-defined object type, it automatically creates the following:

• a custom object class to act as a type definition to correspond to your Oracle object type

  This class includes getter and setter methods for each attribute. The method names are of the form getFoo() and setFoo() for attribute foo.

  Also, you can optionally instruct JPublisher to generate wrapper methods in your class that invoke the associated Oracle object methods executing in the server. This is specified by the -methods=true option, described later in this section.

• a related custom reference class for object references to your Oracle object type

  This class includes a getValue() method that returns an instance of your custom object class, and a setValue() method that updates an object value in the database, taking as input an instance of the custom object class.

• custom classes for any object or collection attributes of the top-level object

  This is necessary so that attributes can be materialized in Java whenever an instance of the top-level class is materialized.

When you run JPublisher for a user-defined collection type, it automatically creates the following:

• a custom collection class to act as a type definition to correspond to your Oracle collection type

  This class includes overloaded getArray() and setArray() methods to retrieve or update a collection as a whole, a getElement() method and setElement() method to retrieve or update individual elements of a collection, and additional utility methods.

• a custom object class for the elements, if the elements of the collection are objects

  This is necessary so that object elements can be materialized in Java whenever an instance of the collection is materialized.

JPublisher-generated custom Java classes in any of these categories implement the CustomDatum interface, the CustomDatumFactory interface, and the getFactory() method.

Generating Custom Java Classes

This section discusses key JPublisher command-line functionality for specifying the user-defined types that you want to map to Java, and for specifying object class names, collection class names, attribute type mappings, and method wrappers. These key points can be summarized as follows:

• Specify user-defined types to map to Java; optionally specify custom object class names and custom collection class names (this involves the JPublisher -sql, -user, and -case options).

• Optionally specify attribute type mappings (this involves the JPublisher -mapping option).

• Optionally instruct JPublisher to create wrapper methods, in particular for Oracle object methods (this involves the JPublisher -methods option).

Specify User-Defined Types to Map to Java

In using JPublisher to create custom Java classes, use the -sql option to specify the user-defined SQL types that you want to map to Java. You can either specify the custom object class names and custom collection class names or you can accept the defaults.

The default names of your top-level custom classes--the classes that will correspond to the user-defined type names you specify to the -sql option--are the same as the user-defined type names as you type them. Because SQL names in the database are case-insensitive, you can capitalize them to ensure that your class names are capitalized per convention. For example, if you want to generate a custom class for employee objects, you can run JPublisher as follows:

% jpub -sql=Employee ...

The default names of lower-level classes, such as for home_address objects that are attributes of employee objects, are determined by the JPublisher -case option. If you do not set the -case option, it is set to mixed. This means that the default for the custom class name is to capitalize the initial character of the corresponding user-defined type name, and the initial character of every word unit thereafter. JPublisher interprets underscores (_), dollar signs ($), and any characters that are illegal in Java identifiers as word-unit separators; these characters are discarded in the process.

For example, for Oracle object type home_address, JPublisher would create class HomeAddress in source file HomeAddress.java.

On the JPublisher command line, use the following syntax for the -sql option (you can specify multiple actions in a single option setting). Use the -user option to specify the database schema.

-sql=udt1<:mapclass1><,udt2<:mapclass2>>,...,<udtN<:mapclassN>>

Following is an example:

% jpub -sql=Myobj,mycoll:MyCollClass -user=scott/tiger

(There can be no space before or after the comma.)

For the Oracle object myobj, this command will name it as you typed it, creating source Myobj.java to define class Myobj. For the Oracle collection mycoll, this command will create source MyCollClass.java to define class MyCollClass.

You can optionally specify schema names as well--for example, the scott schema:

% jpub -sql=scott.Myobj,scott.mycoll:MyCollClass -user=scott/tiger

You cannot specify custom reference class names; JPublisher automatically derives them by adding Ref to custom object class names. For example, if JPublisher produces Java source Myobj.java to define custom object class Myobj, then it will also produce Java source MyobjRef.java to define custom reference class MyobjRef.

To create custom Java classes for the object and collection types defined in "User-Defined Types in the Database", you can run JPublisher as follows:

%jpub -user=scott/tiger -sql=Address,Person,Phone_array,Participant_t,
Module_t,Moduletbl_t

Or, to explicitly specify the custom object class and custom collection class names:

%jpub -user=scott/tiger -sql=Address,Person,phone_array:PhoneArray,
participant_t:ParticipantT,module_t:ModuleT,moduletbl_t:ModuletblT

The second example will produce Java source files Address.java, AddressRef.java, Person.java, PersonRef.java, PhoneArray.java, ParticipantT.java, ParticipantTRef.java, ModuleT.java, ModuleTRef.java, and ModuletblT.java. Examples of some of these source files are provided in "JPublisher Custom Java Class Examples".

So that it knows how to populate the custom Java classes, JPublisher connects to the specified schema (here scott/tiger) to determine attributes of your specified object types or elements of your specified collection types.

If you want to change how JPublisher uses character case in default names for the methods and attributes that it generates, including lower-level custom Java class names for attributes that are objects or collections, you can accomplish this using the -case option. There are four possible settings:

• -case=mixed (default)--The following will be uppercase: the first character of every word unit of a class name, every word unit of an attribute name, and every word unit after the first word unit of a method name. All other characters are in lowercase. JPublisher interprets underscores (_), dollar signs ($), and any characters that are illegal in Java identifiers as word-unit separators; these characters are discarded in the process.

• -case=same--Character case is unchanged from its representation in the database. Underscores and dollar signs are retained; illegal characters are discarded.

• -case=upper--Lowercase letters are converted to uppercase. Underscores and dollar signs are retained; illegal characters are discarded.

• -case=lower--Uppercase letters are converted to lowercase. Underscores and dollar signs are retained; illegal characters are discarded.

Specify Attribute and Element Type Mappings

Oracle datatypes of attributes or elements in user-defined SQL types can be mapped to Java types in one of the following three ways, as specified by the JPublisher -mapping option. This determines what kinds of conversions are performed in transferring data between the database and your application.

• JDBC mapping (default)--Standard Java types such as int, float, or java.lang.BigDecimal are used. This does not protect against null data--assigning null data to primitive types such as int and float will cause an exception.

  See Table 5-1 in "Supported Types for Host Expressions" to see how Oracle datatypes map to Java types.

• Object JDBC mapping--This is like JDBC mapping except that wrapper classes of the java.lang package are used instead of Java primitive types. For example, java.lang.Integer and java.lang.Float are used instead of int and float. This allows null values.

• Oracle mapping--The oracle.sql class that corresponds to the Oracle datatype is used. For example, a NUMBER attribute maps to oracle.sql.NUMBER. Data items in oracle.sql objects are maintained in their raw formats.

Specify attribute and element type mapping with one of the following command-line settings of the JPublisher -mapping option:

-mapping=jdbc
-mapping=objectjdbc
-mapping=oracle

Generate Method Wrappers

In creating custom object classes to map Oracle objects to Java, you can optionally include Java wrappers for Oracle object methods. You can use the JPublisher -methods=true option setting to accomplish this.

You can specify -methods=false to ensure that wrappers are not generated. For release 8.1.5, this is the default.

Wrapper methods generated by JPublisher are always instance methods, even when the original object methods are static. See "Custom Java Class Support for Object Methods" for more information.

The following example shows how to set the -methods option:

% jpub -sql=Myobj,mycoll:MyCollClass -user=scott/tiger -methods=true

This will use default naming--the Java method names will be named in the same fashion as custom Java class names (as described in "Specify User-Defined Types to Map to Java"), except that the initial character will be lowercase. For example, by default an object method name of CALC_SAL results in a Java wrapper method of calcSal().

Alternatively, you can specify desired method names, but this requires use of a JPublisher input file and is discussed in "Creating Custom Java Classes and Specifying Member Names".

If you run JPublisher for an Oracle object that has an overloaded method where multiple signatures have the same corresponding Java signature, then JPublisher will generate a uniquely named method for each signature. It accomplishes this by appending _nn to function names, where nn is a number. This is to ensure that no two methods in the generated custom Java class have the same name and signature. Consider, for example, SQL functions with the following signatures:

F(INTEGER, INTEGER)
F(FLOAT, FLOAT)

Without precaution, these would both result in the following name and signature in Java:

F(oracle.sql.NUMBER, oracle.sql.NUMBER)

(Because both integers and floating point numbers map to the NUMBER class.)

Instead, JPublisher might call one F_1 and the other F_2. (The _nn is unique for each. In simple cases it will likely be _1, _2, and so on, but it may sometimes be arbitrary other than being unique for each).

Generate Custom Java Classes and Map Alternative Classes

You can use JPublisher to generate a custom Java class but instruct it to map the object type (or collection type) to an alternative class instead of to the generated class.

A typical scenario is to treat JPublisher-generated classes as superclasses, subclass them to add functionality, and map the object types to the subclasses. For example, presume you have an Oracle object type ADDRESS and want to produce a custom Java class for it that has functionality beyond what is produced by JPublisher. You can use JPublisher to generate a custom Java class JAddress for the purpose of subclassing it to produce a class MyAddress. Under this scenario you will add any special functionality to MyAddress and will want JPublisher to map ADDRESS objects to that class, not to the JAddress class. You will also want JPublisher to produce a reference class for MyAddress, not JAddress.

Another alternative is to manually create a class that does not subclass the generated class, but instead uses it as a field.

JPublisher has functionality to streamline the process of mapping to alternative classes. Use the following syntax in your -sql option setting:

-sql=object_type:generated_class:map_class

For the above example, use this setting:

-sql=ADDRESS:JAddress:MyAddress

This generates class JAddress in source file JAddress.java, but does the following:

• Maps the object type ADDRESS to the MyAddress class, not to the JAddress class. Therefore, if you retrieve an object from the database that has an ADDRESS attribute, then this attribute will be created as an instance of MyAddress in Java. Or if you retrieve an ADDRESS object directly, presumably you will retrieve it into an instance of MyAddress.

• Creates a MyAddressRef class in MyAddressRef.java, instead of creating a JAddressRef class.

You must manually produce a MyAddress class in source file MyAddress.java. This class can implement your required functionality either by subclassing JAddress or by using JAddress as a class field.

For further discussion about subclassing JPublisher-generated classes or using them as fields (continuing the preceding example), see "Extending or Wrapping Classes Generated by JPublisher".

Using JPublisher Input Files and Properties Files

JPublisher supports the use of special input files and standard properties files to specify type mappings and additional option settings.

Using JPublisher Input Files

You can use the JPublisher -input command-line option to specify an input file for JPublisher to use for additional type mappings.

"SQL" in an input file is equivalent to "-sql" on the command line, and "AS" or "GENERATE...AS" syntax is equivalent to command-line colon syntax. Use the following syntax, specifying just one mapping per SQL command:

SQL udt1 <GENERATE GeneratedClass1> <AS MapClass1>
SQL udt2 <GENERATE GeneratedClass2> <AS MapClass2>
...

This generates GeneratedClass1 and GeneratedClass2, but maps udt1 to MapClass1 and udt2 to MapClass2.

Input File Example

In the following example, JPublisher will pick up the -user option from the command line and go to input file myinput.in for type mappings.

Command line:

% jpub -input=myinput.in -user=scott/tiger

Contents of input file myinput.in:

SQL Myobj
SQL mycoll AS MyCollClass
SQL employee GENERATE Employee AS MyEmployee

This accomplishes the following:

• User-defined type MYOBJ gets the custom object class name Myobj because that's how you typed it--JPublisher creates source Myobj.java (and MyobjRef.java).

• User-defined type MYCOLL is mapped to MyCollClass. JPublisher creates source MyCollClass.java.

• User-defined type EMPLOYEE is mapped to class MyEmployee. JPublisher creates source Employee.java and MyEmployeeRef.java. If you retrieve an object from the database that has an EMPLOYEE attribute, this attribute would be created as an instance of MyEmployee in Java. Or if you retrieve an EMPLOYEE object directly, presumably you will retrieve it into an instance of MyEmployee. You must manually create source MyEmployee.java to define class MyEmployee. MyEmployee would either subclass Employee or wrap it by using one or more Employee objects as attributes.

Using JPublisher Properties Files

You can use the JPublisher -props command-line option to specify a properties file for JPublisher to use for additional type mappings and other option settings.

In a properties file, "jpub." (including the period) is equivalent to the command-line "-" (single-dash), and other syntax remains the same. Specify only one option per line.

For type mappings, for example, "jpub.sql" is equivalent to "-sql". As on the command line, but unlike in an input file, you can specify multiple mappings in a single jpub.sql setting.

Properties File Example

In the following example, JPublisher will pick up the -user option from the command line and go to properties file jpub.properties for type mappings and the attribute-mapping option.

Command line:

% jpub -props=jpub.properties -user=scott/tiger

Contents of properties file jpub.properties:

jpub.sql=Myobj,mycoll:MyCollClass,employee:Employee:MyEmployee
jpub.mapping=oracle

This produces the same results as the input-file example above, except that the oracle attribute-mapping setting is used.

Creating Custom Java Classes and Specifying Member Names

In generating custom Java classes you can specify the names of any attributes or methods of the custom class. This cannot be specified on the JPublisher command line, however. It can only be accomplished in a JPublisher input file using TRANSLATE syntax, as follows:

SQL udt <GENERATE GeneratedClass> <AS MapClass> <TRANSLATE membername1 AS 
Javaname1> <, membername2 AS Javaname2> ...

TRANSLATE pairs (membernameN AS JavanameN) are separated by commas.

For example, presume the Oracle object type EMPLOYEE has an address attribute that you want to call HomeAddress, and a GIVE_RAISE method that you want to call giveRaise(). Also presume that you want to generate an Employee class but map EMPLOYEE objects to a MyEmployee class that you will create (this is not related to specifying member names, but provides a full example of input file syntax).

SQL employee GENERATE Employee AS MyEmployee TRANSLATE address AS HomeAddress, 
GIVE_RAISE AS giveRaise

JPublisher Implementation of Wrapper Methods

Note the following points about how JPublisher-generated method wrappers are generated:

• JPublisher-generated method wrappers are implemented in SQLJ; therefore, whenever -methods=true, the custom object class will be defined in a .sqlj file instead of a .java file. Run SQLJ to translate the .sqlj file.

• All wrapper methods generated by JPublisher are implemented as instance methods. This is because a database connection is required for you to invoke the corresponding server method. Each instance of a JPublisher-generated custom Java class has a connection associated with it.

• Any output or input-output parameter is passed as the element of a one-element array. (This is to work around logistical issues with output and input-output parameters, as discussed in "Custom Java Class Support for Object Methods".) If the parameter is input-output, then the wrapper method takes the array element as input; after processing, the wrapper assigns the output to the array element.

• The this member of an instance of a JPublisher-generated custom Java class is treated differently, however. It can be used as either an input or an input-output parameter, depending on whether the server method actually modifies it. If this is input-output, then it is modified in place. This is as opposed to the way output and input-output parameters are generally handled in custom Java classes, where copies must be made if they are not passed as array elements.

JPublisher Custom Java Class Examples

This section provides examples of JPublisher Java source code output for the following user-defined types (created in "User-Defined Types in the Database"):

• a custom object class (Address, corresponding to the Oracle object type ADDRESS) and related custom reference class (AddressRef)

• a custom collection class (ModuletblT, corresponding to the Oracle collection type MODULETBL_T)

Example: Custom Object Class Source Code for Address.java

Following is an example of the source code that JPublisher generates for a custom object class. Implementation details have been omitted.

In this example, unlike in "Creating Object Types", assume the Oracle object ADDRESS has only the street and zip_code attributes.

package bar;

import java.sql.SQLException;
import oracle.jdbc.driver.OracleConnection;
import oracle.jdbc.driver.OracleTypes;
import oracle.sql.CustomDatum;
import oracle.sql.CustomDatumFactory;
import oracle.sql.Datum;
import oracle.sql.STRUCT;
import oracle.jpub.MutableStruct;

public class Address implements CustomDatum, CustomDatumFactory
{
  public static final String _SQL_NAME = "SCOTT.ADDRESS";
  public static final int _SQL_TYPECODE = OracleTypes.STRUCT;

  public static CustomDatumFactory getFactory()
  { ... }

  /* constructor */
  public Address()
  { ... }

  /* CustomDatum interface */
  public Datum toDatum(OracleConnection c) throws SQLException
  { ... }

  /* CustomDatumFactory interface */
  public CustomDatum create(Datum d, int sqlType) throws SQLException
  { ... }

  /* accessor methods */
  public String getStreet() throws SQLException
  { ... }

  public void setStreet(String street) throws SQLException
  { ... }


  public String getZipCode() throws SQLException
  { ... }

  public void setZipCode(String zip_code) throws SQLException
  { ... }

}

Example: Custom Reference Class Source Code for AddressRef.java

Following is an example of the source code that JPublisher generates for a custom reference class to be used for references to ADDRESS objects. Implementation details have been omitted.

package bar;

import java.sql.SQLException;
import oracle.jdbc.driver.OracleConnection;
import oracle.jdbc.driver.OracleTypes;
import oracle.sql.CustomDatum;
import oracle.sql.CustomDatumFactory;
import oracle.sql.Datum;
import oracle.sql.REF;
import oracle.sql.STRUCT;

public class AddressRef implements CustomDatum, CustomDatumFactory
{
  public static final String _SQL_BASETYPE = "SCOTT.ADDRESS";
  public static final int _SQL_TYPECODE = OracleTypes.REF;

  public static CustomDatumFactory getFactory()
  { ... }

  /* constructor */
  public AddressRef()
  { ... }

  /* CustomDatum interface */
  public Datum toDatum(OracleConnection c) throws SQLException
  { ... }

  /* CustomDatumFactory interface */
  public CustomDatum create(Datum d, int sqlType) throws SQLException
  { ... }

  public Address getValue() throws SQLException
  { ... }

  public void setValue(Address c) throws SQLException
  { ... }
}

Example: Custom Collection Class Source Code for ModuletblT.java

Following is an example of the source code that JPublisher generates for a custom collection class. Implementation details have been omitted.

import java.sql.SQLException;
import oracle.jdbc.driver.OracleConnection;
import oracle.jdbc.driver.OracleTypes;
import oracle.sql.CustomDatum;
import oracle.sql.CustomDatumFactory;
import oracle.sql.Datum;
import oracle.sql.ARRAY;
import oracle.sql.ArrayDescriptor;
import oracle.jpub.runtime.MutableArray;

public class ModuletblT implements CustomDatum, CustomDatumFactory
{
  public static final String _SQL_NAME = "SCOTT.MODULETBL_T";
  public static final int _SQL_TYPECODE = OracleTypes.ARRAY;

  public static CustomDatumFactory getFactory()
  { ... }

  /* constructors */
  public ModuletblT()
  { ... }

  public ModuletblT(ModuleT[] a)
  { ... }

  /* CustomDatum interface */
  public Datum toDatum(OracleConnection c) throws SQLException
  { ... }

  /* CustomDatumFactory interface */
  public CustomDatum create(Datum d, int sqlType) throws SQLException
  { ... }

  public String getBaseTypeName() throws SQLException
  { ... }

  public int getBaseType() throws SQLException
  { ... }

  public ArrayDescriptor getDescriptor() throws SQLException
  { ... }

  /* array accessor methods */
  public ModuleT[] getArray() throws SQLException
  { ... }

  public void setArray(ModuleT[] a) throws SQLException
  { ... }

  public ModuleT[] getArray(long index, int count) throws SQLException
  { ... }

  public void setArray(ModuleT[] a, long index) throws SQLException
  { ... }

  public ModuleT getObjectElement(long index) throws SQLException
  { ... }

  public void setElement(ModuleT a, long index) throws SQLException
  { ... }
}

Extending or Wrapping Classes Generated by JPublisher

You might want to enhance the functionality of a custom Java class generated by JPublisher by adding methods and transient fields. You can accomplish this in either of the following ways:

• You can subclass the JPublisher-generated class.

or:

• You can write a new class that wraps the JPublisher-generated class. You can use the generated class type for a field in your custom class, delegating functionality to this field.

For example, suppose you want JPublisher to generate the class JAddress from the SQL object type ADDRESS. You also want to write a class MyAddress to represent ADDRESS objects and implement special functionality. The MyAddress class that you write can either extend JAddress or can have a JAddress field.

Another way to enhance the functionality of a JPublisher-generated class is to simply add methods to it. However, adding methods to the generated class is not recommended if you anticipate running JPublisher at some future time to regenerate the class. If you run JPublisher to regenerate a class that you have modified in this way, you would have to save a copy and then manually merge your changes back in.

JPublisher Functionality for Extending or Wrapping Generated Classes

As discussed in "Generate Custom Java Classes and Map Alternative Classes", the JPublisher syntax to generate JAddress but map to MyAddress is as follows:

-sql=ADDRESS:JAddress:MyAddress

Or, in an input file:

SQL ADDRESS GENERATE JAddress AS MyAddress

As a result of this, JPublisher will generate the REF class MyAddressRef (in MyAddressRef.java) rather than JAddressRef.

Also, JPublisher alters the code it generates to implement the following functionality:

• The MyAddress class is used instead of the JAddress class to represent attributes whose database type is ADDRESS.

• The MyAddress class is used instead of the JAddress class to represent method arguments and function results whose type is ADDRESS.

• The MyAddress factory is used instead of the JAddress factory to construct Java objects whose database type is ADDRESS.

You would presumably use MyAddress similarly in any additional code that you write.

At runtime the Oracle JDBC driver will map any occurrences of ADDRESS data in the database to MyAddress instances instead of JAddress instances.

Requirements of Extended or Wrapper Classes

The class that you create (for example, MyAddress.java) must have the following features:

• It must have a no-argument constructor. The easiest way to construct a properly initialized object is to invoke the constructor of the superclass, either explicitly or implicitly.

• It must implement the CustomDatum interface. If you are subclassing the class generated by JPublisher, then you can inherit the toDatum() method from the generated class. If you are using the generated class as a field, then you can call its toDatum() method.

• It must define the fields _SQL_NAME and _SQL_TYPECODE. If you are subclassing the JPublisher-generated class, then you can inherit these. If you are wrapping the generated class then you must add this code yourself. You can copy the field definitions from the generated class.

• It or another class must implement the CustomDatumFactory interface. For example, you can have a class MyAddress that implements CustomDatum and a class MyAddressFactory that implements CustomDatumFactory.

• It must have a getFactory() method that returns an instance of your map class (such as a MyAddress object).

Example of Class Generated by JPublisher

Continuing the example in the preceding sections, here is sample code for the JPublisher-generated class (JAddress). Implementation details have been omitted.

import java.sql.SQLException;
import oracle.jdbc.driver.OracleConnection;
import oracle.jdbc.driver.OracleTypes;
import oracle.sql.CustomDatum;
import oracle.sql.CustomDatumFactory;
import oracle.sql.Datum;
import oracle.sql.STRUCT;
import oracle.jpub.runtime.MutableStruct;

public class JAddress implements CustomDatum, CustomDatumFactory
{
  public static final String _SQL_NAME = "SCOTT.ADDRESS";
  public static final int _SQL_TYPECODE = OracleTypes.STRUCT;

  public static CustomDatumFactory getFactory()
  { ... }

  /* constructor */
  public JAddress()
  { ... }

  /* CustomDatum interface */
  public Datum toDatum(OracleConnection c) throws SQLException
  { ... }

  /* CustomDatumFactory interface */
  public CustomDatum create(Datum d, int sqlType) throws SQLException
  { ... }

  /* shallow copy method: give object same attributes as argument */
  void shallowCopy(JAddress d) throws SQLException
  { ... }

  /* accessor methods */
  public String getStreet() throws SQLException
  { ... }

  public void setStreet(String street) throws SQLException
  { ... }


  public String getCity() throws SQLException
  { ... }

  public void setCity(String city) throws SQLException
  { ... }

  public String getState() throws SQLException
  { ... }

  public void setState(String state) throws SQLException
  { ... }

  public java.math.BigDecimal getZip() throws SQLException
  { ... }

  public void setZip(java.math.BigDecimal zip) throws SQLException
  { ... }

}

Example of Reference Class Generated by JPublisher

Continuing the example in the preceding sections, here is sample code for the JPublisher-generated reference class (MyAddressRef, as opposed to JAddressRef, because MyAddress is the class that ADDRESS objects map to). Implementation details have been omitted.

import java.sql.SQLException;
import oracle.jdbc.driver.OracleConnection;
import oracle.jdbc.driver.OracleTypes;
import oracle.sql.CustomDatum;
import oracle.sql.CustomDatumFactory;
import oracle.sql.Datum;
import oracle.sql.REF;
import oracle.sql.STRUCT;

public class MyAddressRef implements CustomDatum, CustomDatumFactory
{
  public static final String _SQL_BASETYPE = "SCOTT.ADDRESS";
  public static final int _SQL_TYPECODE = OracleTypes.REF;

  public static CustomDatumFactory getFactory()
  { ... }

  /* constructor */
  public MyAddressRef()
  { ... }

  /* CustomDatum interface */
  public Datum toDatum(OracleConnection c) throws SQLException
  { ... }

  /* CustomDatumFactory interface */
  public CustomDatum create(Datum d, int sqlType) throws SQLException
  { ... }

  public MyAddress getValue() throws SQLException
  { ... }

  public void setValue(MyAddress c) throws SQLException
  { ... }
}

Example of Extending JPublisher-Generated Class

Continuing the example in the preceding sections, here is sample code for a MyAddress class that subclasses the JPublisher-generated JAddress class. This code is somewhat generic, showing such things as what is inherited from JAddress. Implementation detail has been omitted.

import java.sql.SQLException;
import oracle.sql.CustomDatum;
import oracle.sql.CustomDatumFactory;
import oracle.sql.Datum;
import oracle.sql.STRUCT;
import oracle.jpub.runtime.MutableStruct;

public class MyAddress extends JAddress
{
  /* _SQL_NAME inherited from MyAddress */
  /* _SQL_TYPECODE inherited from MyAddress */

  static _myAddressFactory = new MyAddress();

  public static CustomDatumFactory getFactory()
  {
    return _myAddressFactory;
  }

  /* constructor */
  public MyAddress()
  { super(); }

  /* CustomDatum interface */
  /* toDatum() inherited from JAddress */

  /* CustomDatumFactory interface */
  public CustomDatum create(Datum d, int sqlType) throws SQLException
  { ... }

  /* accessor methods inherited from JAddress */

  /* Additional methods go here.  These additional methods (not shown)
     are the reason that JAddress was extended.
  */
}
 

Example of Wrapping JPublisher-Generated Class

This is another example of producing a MyAddress class to enhance the functionality of the generated JAddress class, but using a JAddress field (data) instead of subclassing JAddress.

import java.sql.SQLException;
import oracle.jdbc.driver.OracleConnection;
import oracle.jdbc.driver.OracleTypes;
import oracle.sql.CustomDatum;
import oracle.sql.CustomDatumFactory;
import oracle.sql.Datum;
import oracle.sql.STRUCT;
import oracle.jpub.runtime.MutableStruct;

public class MyAddress implements CustomDatum, CustomDatumFactory {
  /* the container for the wrapped object */
  private JAddress data;

  // use these from JAddress
  public static final String _SQL_NAME = "SCOTT.ADDRESS";
  public static final int _SQL_TYPECODE = OracleTypes.STRUCT;

  static final MyAddress _MyAddressFactory = new MyAddress();
  public static CustomDatumFactory getFactory()
  {
    return _MyAddressFactory;
  }

  /* constructor */
  public MyAddress()
  {
    data = new JAddress();
  }

  /* CustomDatum interface */
  public Datum toDatum(OracleConnection c) throws SQLException
  {
    return data.toDatum(c);
  }

  /* CustomDatumFactory interface */
  public CustomDatum create(Datum d, int sqlType) throws SQLException
  {
    if (d == null) return null;
    MyAddress o = new MyAddress();
    o.data = (JAddress) JAddress.getFactory().create(d, sqlType);
    return o;
  }

  /* accessor methods.  These simply delegate to the wrapped object */
  public String getV1() throws SQLException
  { return data.getV1(); }

  public void setV1(String v1) throws SQLException
  { data.setV1(v1); }

  public String getV2() throws SQLException
  { return data.getV2(); }

  public void setV2(String v2) throws SQLException
  { data.setV2(v2); }

  public String getV3() throws SQLException
  { return data.getV3(); }

  public void setV3(String v3) throws SQLException
  { data.setV3(v3); }

  public String getV4() throws SQLException
  { return data.getV4(); }

  public void setV4(String v4) throws SQLException
  { data.setV4(v4); }

  /* add methods here for any additional desired MyAddress functionality */
}

---