最近我开始升级我的应用程序JDK版本,从jdk1.7.0_121_x64升级到jdk1.8.0_202_x64。我有一些使用Drools 5.4.0.Final的旧代码。这段代码在JDK版本jdk1.7.0_121_x64下运行正常。
Maven依赖关系如下:
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-core</artifactId>
<version>5.4.0.Final</version>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-decisiontables</artifactId>
<version>5.4.0.Final</version>
</dependency>
DRL文件的加载方式如下:
final KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
final KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(resource, ResourceType.DRL);
knowledgeBase.addKnowledgePackages(kbuilder.getKnowledgePackages());
我知道在使用JDK 8时使用Drools可能会出现问题。我参考了其他SO线程进行了起步。
当我使用JDK 8构建我的应用程序并执行Junit测试时,测试失败并显示错误:
testRunRule(com.company.app.RuleTest) Time elapsed: 0.073 sec <<< ERROR!
java.lang.RuntimeException: java.lang.RuntimeException: wrong class format
at org.eclipse.jdt.internal.compiler.classfmt.ClassFileReader.<init>(ClassFileReader.java:372)
at org.drools.commons.jci.compilers.EclipseJavaCompiler$2.createNameEnvironmentAnswer(EclipseJavaCompiler.java:287)
at org.drools.commons.jci.compilers.EclipseJavaCompiler$2.findType(EclipseJavaCompiler.java:258)
如此SO线程所述,我找到了这个bugfix票据DROOLS-329的参考。
根据这个bugfix票据中提到的方法,我尝试使用JANINO编译器:
添加以下Maven依赖项:
<dependency>
<groupId>org.codehaus.janino</groupId>
<artifactId>janino</artifactId>
<version>2.5.16</version>
</dependency>
我添加了以下VM参数(我是从Eclipse运行测试的,因此在Eclipse启动配置中的JRE VM参数中添加了该参数):
我添加了以下VM参数(我是从Eclipse运行测试的,因此在Eclipse启动配置中的JRE VM参数中添加了该参数):
-Ddrools.dialect.java.compiler=JANINO
我仍然看到了错误的类格式错误。因此,我修改了我的代码,将DRL文件加载为:
final KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
final Properties props = new Properties();
props.setProperty("drools.dialect.java.compiler", "JANINO");
final KnowledgeBuilderConfiguration config = KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration(props, null);
final KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(config);
kbuilder.add(resource, ResourceType.DRL);
knowledgeBase.addKnowledgePackages(kbuilder.getKnowledgePackages());
没用,我仍然能看到错误的类格式错误。
我按照这个外部链接提到的另一种方法尝试。我更新了Maven依赖,添加/更新如下:
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-core</artifactId>
<version>5.4.0.Final</version>
<exclusions>
<exclusion>
<groupId>org.mvel</groupId>
<artifactId>mvel2</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.drools</groupId>
<artifactId>drools-decisiontables</artifactId>
<version>5.4.0.Final</version>
<exclusions>
<exclusion>
<groupId>org.eclipse.jdt.core.compiler</groupId>
<artifactId>ecj</artifactId>
</exclusion>
<exclusion>
<groupId>org.mvel</groupId>
<artifactId>mvel2</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.mvel</groupId>
<artifactId>mvel2</artifactId>
<version>2.1.9.Final</version>
</dependency>
<dependency>
<groupId>org.eclipse.jdt.core.compiler</groupId>
<artifactId>ecj</artifactId>
<version>4.6.1</version>
</dependency>
mvel2 补丁是使用以下方式构建的: https://github.com/mkornipati/mvel/tree/2.1.9.Final.Patch
由此,错误的类格式问题已经解决。但我的测试现在失败,出现以下错误:
testRunRule(com.company.app.RuleTest)) Time elapsed: 4.684 sec <<< ERROR!
java.lang.RuntimeException: org.drools.rule.InvalidRulePackage: Rule Compilation error : [Rule name='ruleCheck']
org/drools/template/parser/Rule_ruleCheck_8eb4621227714a36b7b84c8b764527e4.java (2:80) : Only a type can be imported. java.util.Map resolves to a package
org/drools/template/parser/Rule_ruleCheck_8eb4621227714a36b7b84c8b764527e4.java (2:101) : Only a type can be imported. java.util.HashMap resolves to a package
org/drools/template/parser/Rule_ruleCheck_8eb4621227714a36b7b84c8b764527e4.java (6:299) : org.drools.spi.KnowledgeHelper cannot be resolved to a type
org/drools/template/parser/Rule_ruleCheck_8eb4621227714a36b7b84c8b764527e4.java (6:339) : org.drools.template.parser.Row cannot be resolved to a type
org/drools/template/parser/Rule_ruleCheck_8eb4621227714a36b7b84c8b764527e4.java (6:373) : org.drools.FactHandle cannot be resolved to a type
org/drools/template/parser/Rule_ruleCheck_8eb4621227714a36b7b84c8b764527e4.java (6:411) : org.drools.template.parser.DefaultGenerator cannot be resolved to a type
org/drools/template/parser/Rule_ruleCheck_8eb4621227714a36b7b84c8b764527e4.java (6:487) : org.drools.runtime.rule.RuleContext cannot be resolved to a type
at org.drools.rule.Package.checkValidity(Package.java:445)
我不知道该怎么继续下去。如果你能让Drools 5.4适配JDK 8,请告诉我。
RuleTest
类在哪里? - hfontanez