[jboss-jira] [JBoss JIRA] (JASSIST-243) Create class by abstract generic template

[Karol Kowalczyk (JIRA)]

    [ https://issues.jboss.org/browse/JASSIST-243?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13039700#comment-13039700 ] 

Karol Kowalczyk edited comment on JASSIST-243 at 2/12/15 3:10 AM:
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I'd like to generate new class from generic abstract template. A try to get this by javassist like this:
CtClass newClass = POOL.makeClass("test.templates.impl.GeneratedBigDecimalAction", genericAbstractTemplateClass);
String newGenericSignature="<Ljava/math/BigDecimal;Ljava/lang/String;Ltest/impl/NumberLogic;>Ltest/impl/ActionRoot<Ljava/math/BigDecimal;Ljava/lang/String;Ltest/impl/NumberLogic;>;Ltest/templates/api/IActionNumber2<Ljava/math/BigDecimal;Ljava/lang/String;>;"
newClass.setGenericSignature(genericSignature);
newClass.writeFile("target\test-classes");
newClass.POOL.get(newClass.getName());

But when I try to compile java sources with generated newClass test.templates.impl.GeneratedBigDecimalAction.class, a have error like this:

src\test\java\test\BigDecimalActionTest.java:[13,-1] cannot access test.templates.impl.GeneratedBigDecimalAction
bad class file: target\test-classes\test\templates\impl\GeneratedBigDecimalAction.class
bad signature:  <null> bu

Why?

1. source of template (generic abstract template)

package test.templates.impl;
import test.impl.INumberLogic;
import test.impl.ActionRoot;
import java.util.Collection;
import test.templates.api.IActionNumber2;

public abstract class AActionNumber<
Dto extends Number,
Pk,
L extends INumberLogic<Dto, Pk>> extends ActionRoot<Dto, Pk, L>
	implements IActionNumber2<Dto, Pk> {
	final protected transient Logger logger = LoggerFactory
			.getLogger(getClass());

	public AActionNumber() throws Exception {
		super();
	}

	public Class<Dto> getPersistentClass() {
		Class<Dto> result = null;
		if (logic != null) {
			result = logic.getPersistentClass();
		}
		return result;
	}
	@Override
	public String echo(String a) {
		return a;
	}
}

2. generic super class ActionRoot:

package test.impl;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.TypeVariable;
public class ActionRoot<
Dto extends Number,
Pk,
L extends INumberLogic<Dto, Pk>> {

	protected L logic;

	@SuppressWarnings({ "unchecked" })
	public ActionRoot() throws Exception {
		Class<?> tmpClass = this.getClass();
		while (!(tmpClass.getGenericSuperclass() instanceof ParameterizedType)) {
			tmpClass = tmpClass.getSuperclass();
		}

		Class<L> logicBeanClass = (Class<L>) ((ParameterizedType) tmpClass
				.getGenericSuperclass()).getActualTypeArguments()[2];

		try {
			logic = (L) logicBeanClass.newInstance();
		} catch (Exception ex) {
			throw new Exception("Problem z utworzeniem obiektu beanu logic", ex);
		}
	}

}

3. Generic interfaces:

package test.impl;
public interface INumberLogic<Dto extends Number, Pk> {
	Class<Dto> getPersistentClass();
}

package test.templates.api;
public interface IActionNumber2<Dto extends Number, Pk> {
	String echo(String a);
}


was (Author: karol.kowalczyk):
I'd like to generate new class from generic abstract template. A try to get this by javassist like this:
CtClass newClass = POOL.makeClass("test.templates.impl.GeneratedBigDecimalAction", genericAbstractTemplateClass);
String newGenericSignature="<Ljava/math/BigDecimal;Ljava/lang/String;Ltest/impl/NumberLogic;>Ltest/impl/ActionRoot<Ljava/math/BigDecimal;Ljava/lang/String;Ltest/impl/NumberLogic;>;Ltest/templates/api/IActionNumber2<Ljava/math/BigDecimal;Ljava/lang/String;>;"
newClass.setGenericSignature(genericSignature);
newClass.writeFile("target/testClasses");
newClass.POOL.get(newClass.getName());

But when I try to compile java sources with generated newClass test.templates.impl.GeneratedBigDecimalAction.class, a have error like this:

src\test\java\test\BigDecimalActionTest.java:[13,-1] cannot access test.templates.impl.GeneratedBigDecimalAction
bad class file: target\test-classes\test\templates\impl\GeneratedBigDecimalAction.class
bad signature:  <null> bu

Why?

1. source of template (generic abstract template)

package test.templates.impl;
import test.impl.INumberLogic;
import test.impl.ActionRoot;
import java.util.Collection;
import test.templates.api.IActionNumber2;

public abstract class AActionNumber<
Dto extends Number,
Pk,
L extends INumberLogic<Dto, Pk>> extends ActionRoot<Dto, Pk, L>
	implements IActionNumber2<Dto, Pk> {
	final protected transient Logger logger = LoggerFactory
			.getLogger(getClass());

	public AActionNumber() throws Exception {
		super();
	}

	public Class<Dto> getPersistentClass() {
		Class<Dto> result = null;
		if (logic != null) {
			result = logic.getPersistentClass();
		}
		return result;
	}
	@Override
	public String echo(String a) {
		return a;
	}
}

2. generic super class ActionRoot:

package test.impl;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.TypeVariable;
public class ActionRoot<
Dto extends Number,
Pk,
L extends INumberLogic<Dto, Pk>> {

	protected L logic;

	@SuppressWarnings({ "unchecked" })
	public ActionRoot() throws Exception {
		Class<?> tmpClass = this.getClass();
		while (!(tmpClass.getGenericSuperclass() instanceof ParameterizedType)) {
			tmpClass = tmpClass.getSuperclass();
		}

		Class<L> logicBeanClass = (Class<L>) ((ParameterizedType) tmpClass
				.getGenericSuperclass()).getActualTypeArguments()[2];

		try {
			logic = (L) logicBeanClass.newInstance();
		} catch (Exception ex) {
			throw new Exception("Problem z utworzeniem obiektu beanu logic", ex);
		}
	}

}

3. Generic interfaces:

package test.impl;
public interface INumberLogic<Dto extends Number, Pk> {
	Class<Dto> getPersistentClass();
}

package test.templates.api;
public interface IActionNumber2<Dto extends Number, Pk> {
	String echo(String a);
}

> Create class by abstract generic template
> -----------------------------------------
>
>                 Key: JASSIST-243
>                 URL: https://issues.jboss.org/browse/JASSIST-243
>             Project: Javassist
>          Issue Type: Bug
>    Affects Versions: 3.19.0-GA
>            Reporter: Karol Kowalczyk
>            Assignee: Shigeru Chiba
>            Priority: Critical
>




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