Java code and modeling correspondence

Introduction

Listed below are the usual concepts for Java development, together with the way in which they can be expressed in Objecteering.

Notions on a package

Java notion ...	UML model mapping ...
generating a sub-package from a larger project, without having the entire package hierarchy	the {JavaName} tagged value with the parameter containing the complete name on the package in question

Notions on a class

Java notion ...	UML model mapping ...
interface	"interface" stereotype on a class
abstract class	"Abstract" field of a class
final class	"Leaf" field of a class.
generalization	class generalization, or {JavaExtends} tagged value
interface implementation	implementation link, or {JavaImplements} tagged value
imports classes	use and reference links of its package, or {JavaImport} tagged value on the class and its package
class invariant	constraint on class, stereotyped “JavaInvariant”
inner class	JavaMembers type of note, or contained class not carrying the {JavaNonPublic} tagged value
non public class	JavaBottom note type, or contained class carrying the {JavaNonPublic} tagged value

Notions on an operation

Java notion ...	mapping in the model ...
public visibility	Public value of the Visibility field on an operation.
protected visibility	Protected value of the Visibility field on an operation.
private visibility	Private value of the Visibility field on an operation.
friendly visibility	None value of the Visibility field on an operation.
constructor	“create” stereotype on an operation
finalize() method	“destroy” stereotype on an operation
abstract	"Abstract" operation field.
static	"Class" operation field.
final	"Cannot be specialized" operation field.
synchronized	{JavaSynchronized} tagged value
native	{JavaNative} tagged value
exceptions generated by an operation	{JavaThrownException} tagged value. You can model the throwing of exceptions through a dependency link towards a class which derives from java.lang.Exception or towards a signal stereotyped <<Exception>>.

Notions on an attribute

Java notion ...	mapping in the model ...
visibility	same mapping process as for the methods.
static	Class field of an attribute.
final	{JavaFinal} tagged value

Code generation for an attribute or association accessor

Please note that this paragraph is only relevant in the context of "JavaTypes" packages.

For each attribute or association in a class, a data member declaration and a number of access methods to this data member are generated. There are two groups of access methods, one for reading ("getX()","isX()" or "cardX()") and the other for modification ("setX()", "appendX()","eraseX()" and so on).

When accessors are generated, the first letter of the attribute name is put into capitals and is prefixed as follows:

	No access	Read	Write	Read-write
Attribute accessors of boolean type	No accessor generated	is<AttributeName>	set<AttributeName>	is<AttributeName> set<AttributeName>
Attibute accessors of other types	No accessor generated	get<AttributeName>	set<AttributeName>	get<AttributeName> set<AttributeName>
Associations	No accessor generated	get<AssociationRole> card<AssociationRole>	set<AssociationRole> append<AssociationRole> erase<AssociationRole>	get<AssociationRole> card<AssociationRole> set<AssociationRole> append<AssociationRole> erase<AssociationRole>

Note: To generate boolean type attribute accessors in the form of "get<AttributeName>", you should simply uncheck the "Java Bean like accessor generation" option, present in the "Generation options" set of parameters.

Example 1

By default, the "ready" boolean type attribute is generated as follows:

boolean ready;

boolean isReady() {

return this.ready;

}

void setReady(boolean value) {

this.ready = value;

}

Example 2

By default, the "index" int type attribute is generated as follows:

int index;

int getIndex() {

return this.index;

}

void setIndex(int value) {

this.index = value;

}

Code generation for an attribute or association accessor for Java 5

Please note that this paragraph is only relevant in the context of "JavaTypes" packages.

For each attribute or association in a class, a data member declaration and a number of access methods to this data member are generated. There are two groups of access methods, one for reading ("getX()" or "isX()") and the other for modification ("setX()", and so on).

When accessors are generated, the first letter of the attribute name is put into capitals and is prefixed as follows:

	No access	Read	Write	Read-write
Attribute accessors of boolean type	No accessor generated	is<AttributeName>	set<AttributeName>	is<AttributeName> set<AttributeName>
Attibute accessors of other types	No accessor generated	get<AttributeName>	set<AttributeName>	get<AttributeName> set<AttributeName>
Associations	No accessor generated	get<AssociationRole>	set<AssociationRole>	get<AssociationRole> set<AssociationRole>

Example

private List<Student> student = new ArrayList<Student> ();

List<Student> getStudent () {
return this.student;
}

void setStudent (List<Student> value) {
this.student = value;
}

Code generation for an enumeration

Since there was no "enum" in Java before Java 5, a special class is generated for a UML enumeration.

For example, if a "Color" enumeration with a number of enumeration literals (red, green, blue) is defined, the code generated is as follows:

public class Color

{

private int value;

public static final Color red = new Color(0);

public static final Color green = new Color(1);

public static final Color blue = new Color(2);

private Color(int code) {

value = code;

}

An enumeration of package is generated as a class in the package, and an enumeration of class is generated as a non public class in the file of its owned class.

Note: If you choose to activate the "Compatible 432" option, an enumeration of package generates no code, and an enumeration of class is generated as an interface that is implemented by its owned class.

For example, for a "Color" enumeration in the "C" class, the generated code is as follows:

public class C implements Color

{

}

interface Color

{

static int red = 0;

static int green = 1;

static int blue = 2;

}

public java.lang.String toString ()

This returns the value of the enumeration.

Public int toInt ()

This returns the integer associated with the enumeration.

Public static Color fromString (String str)

This returns an enumeration from its string.

When the "Generate Java 5 enumerations" parameter tickbox is checked, Objecteering generates Java 5 enumerations. Because of limitations in the Objecteering metamodel, these can only contain literals and not methods or attributes.