Bug in developer preview
Marcos Antonio
marcos_antonio_ps at hotmail.com
Thu Sep 19 07:24:21 PDT 2013
Hello, Vicente. Unfortunately I can't send you the whole class as this class has lots of dependencies in my application and I would need to send you the whole application instead. But maybe trying a simple code like this:
private void sort()
{
final Comparator<T> ASCENDING_ORDER = nullsFirst(comparing(e -> someGenericMethod(e)));
_entities.sort(ASCENDING_ORDER);
}
// Just returns the value of some property from the entity that is also Comparable
private <V extends Comparable<? super V>> V someGenericMethod(T entity)
{
Object value = ...
return (V) value;
}
would show something.
Sorry to write to just copy my code in Portuguese. I was in a hurry. Here it is in English:
private void sort()
{
final Comparator<T> ASCENDING_ORDER =
new Comparator<T>()
{
@Override
public int compare(T entity1, T entity2)
{
Object value1 = getOrderPropertyValue(entity1);
Object value2 = getOrderPropertyValue(entity2);
return compareValues(value1, value2);
}
private Object getOrderPropertyValue(T entity)
{
EntityStructure entityStructure =
_currentEntityStructures.get(entity);
ObjectProperty objectProperty =
entityStructure.objectProperties.get(
_orderPropertyName);
return objectProperty.getValue();
}
@SuppressWarnings("unchecked")
private <V> int compareValue(V value1, V value2)
{
if (value1 != null && value2 != null)
{
return ((Comparable<V>) value1).compareTo(value2);
}
else
{
return value1 == value2 ? 0 : (value1 == null ? 1 : -1);
}
}
};
_entities.sort(ASCENDING_ORDER);
// ...
}
Then I tried to convert it to use lambda expression:
private void sort()
{
final Comparator<T> ASCENDING_ORDER =
nullsFirst(comparing(e -> getOrderPropertyValue(e)));
_entities.sort(ASCENDING_ORDER);
// ...
}
@SuppressWarnings("unchecked")
private <V extends Comparable<? super V>> V getOrderPropertyValue(T entity)
{
EntityStructure entityStructure =
_currentEntityStructures.get(entity);
ObjectProperty objectProperty =
entityStructure.objectProperties.get(
_orderPropertyName);
return (V) objectProperty.getValue();
}
Marcos
> Date: Thu, 19 Sep 2013 11:05:24 +0100
> From: vicente.romero at oracle.com
> To: marcos_antonio_ps at hotmail.com
> CC: lambda-dev at openjdk.java.net
> Subject: Re: Bug in developer preview
>
> Hi Marcos Antonio,
>
> This seems to be an important bug, but the report is incomplete. Could
> you please send me the whole class.
>
> Also as a side comment, I think that using English identifiers makes the
> code easier to understand by a wider audience, even if you don't speak
> Portuguese ;)
>
> Thanks,
> Vicente
>
> On 19/09/13 02:11, Marcos Antonio wrote:
>> I'm using JDK 8 Developer Preview (b106)
>>
>> First I had this code in a class of mine:
>>
>> private void ordenar()
>> {
>> final Comparator<T> ORDEM_CRESCENTE =
>> new Comparator<T>()
>> {
>> @Override
>> public int compare(T entidade1, T entidade2)
>> {
>> Object valor1 = obterValorPropriedadeOrdem(entidade1);
>> Object valor2 = obterValorPropriedadeOrdem(entidade2);
>> return comparar(valor1, valor2);
>> }
>>
>> private Object obterValorPropriedadeOrdem(T entidade)
>> {
>> EstruturaEntidade estruturaEntidade =
>> _estruturasEntidadesAtuais.get(entidade);
>> PropriedadeObjeto propriedadeObjeto =
>> estruturaEntidade.propriedadesObjetos.get(
>> _nomePropriedadeOrdem);
>> return propriedadeObjeto.getValor();
>> }
>> @SuppressWarnings("unchecked")
>> private <V> int comparar(V valor1, V valor2)
>> {
>> if (valor1 != null && valor2 != null)
>> {
>> return ((Comparable<V>) valor1).compareTo(valor2);
>> }
>> else
>> {
>> return valor1 == valor2 ? 0 : (valor1 == null ? 1 : -1);
>> }
>> }
>> };
>>
>> _entidades.sort(ORDEM_CRESCENTE);
>> // ...
>> }
>>
>> Then I tried to convert it to use lambda expression:
>>
>> private void ordenar()
>> {
>> final Comparator<T> ORDEM_CRESCENTE =
>> nullsFirst(comparing(e -> obterValorPropriedadeOrdem(e)));
>>
>> _entidades.sort(ORDEM_CRESCENTE);
>> // ...
>> }
>>
>> @SuppressWarnings("unchecked")
>> private <V extends Comparable<? super V>> V obterValorPropriedadeOrdem(T entidade)
>> {
>> EstruturaEntidade estruturaEntidade =
>> _estruturasEntidadesAtuais.get(entidade);
>> PropriedadeObjeto propriedadeObjeto =
>> estruturaEntidade.propriedadesObjetos.get(
>> _nomePropriedadeOrdem);
>> return (V) propriedadeObjeto.getValor();
>> }
>>
>> Now I get this error when I compile:
>>
>> [javac] An exception has occurred in the compiler (1.8.0-ea). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport) after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report. Thank you.
>> [javac] java.lang.NullPointerException
>> [javac] at com.sun.tools.javac.code.Types$DescriptorCache.get(Types.java:392)
>> [javac] at com.sun.tools.javac.code.Types.findDescriptorSymbol(Types.java:563)
>> [javac] at com.sun.tools.javac.code.Types.isFunctionalInterface(Types.java:579)
>> [javac] at com.sun.tools.javac.code.Types.functionalInterfaceBridges(Types.java:662)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor$TranslationContext.<init>(LambdaToMethod.java:1669)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor$LambdaTranslationContext.<init>(LambdaToMethod.java:1722)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.makeLambdaContext(LambdaToMethod.java:1618)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitLambda(LambdaToMethod.java:1213)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCLambda.accept(JCTree.java:1619)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.visitApply(TreeTranslator.java:275)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1459)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.visitApply(TreeTranslator.java:275)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCMethodInvocation.accept(JCTree.java:1459)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.visitVarDef(TreeTranslator.java:153)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitVarDef(LambdaToMethod.java:1381)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:846)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.visitBlock(TreeTranslator.java:162)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitBlock(LambdaToMethod.java:1123)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCBlock.accept(JCTree.java:903)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.visitMethodDef(TreeTranslator.java:145)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitMethodDef(LambdaToMethod.java:1233)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:772)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:70)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.visitClassDef(TreeTranslator.java:134)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.visitClassDef(LambdaToMethod.java:1160)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:687)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.analyzeAndPreprocessClass(LambdaToMethod.java:1113)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod$LambdaAnalyzerPreprocessor.access$300(LambdaToMethod.java:1083)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod.visitClassDef(LambdaToMethod.java:218)
>> [javac] at com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:687)
>> [javac] at com.sun.tools.javac.tree.TreeTranslator.translate(TreeTranslator.java:58)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod.translate(LambdaToMethod.java:183)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod.translate(LambdaToMethod.java:176)
>> [javac] at com.sun.tools.javac.comp.LambdaToMethod.translateTopLevelClass(LambdaToMethod.java:203)
>> [javac] at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1465)
>> [javac] at com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1350)
>> [javac] at com.sun.tools.javac.main.JavaCompiler.compile2(JavaCompiler.java:900)
>> [javac] at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:859)
>> [javac] at com.sun.tools.javac.main.Main.compile(Main.java:523)
>> [javac] at com.sun.tools.javac.main.Main.compile(Main.java:381)
>> [javac] at com.sun.tools.javac.main.Main.compile(Main.java:370)
>> [javac] at com.sun.tools.javac.main.Main.compile(Main.java:361)
>> [javac] at com.sun.tools.javac.Main.compile(Main.java:64)
>> [javac] at com.sun.tools.javac.Main.main(Main.java:50)
>>
>> Sorry if I can't give you a simpler example, but I think you can come up with something simple and similar.
>>
>> Marcos
>>
>
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