Drools执行报错 The Eclipse JDT Core jar is not in the classpath .

在升级jboss测试Drools时，Eclipse后台报以下错误：

org.drools.RuntimeDroolsException: Unable to load dialect 'org.drools.rule.builder.dialect.java.JavaDialectConfiguration:java'
at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:160)
at org.drools.compiler.PackageBuilderConfiguration.buildDialectConfigurationMap(PackageBuilderConfiguration.java:146)
at org.drools.compiler.PackageBuilderConfiguration.init(PackageBuilderConfiguration.java:121)
at org.drools.compiler.PackageBuilderConfiguration.<init>(PackageBuilderConfiguration.java:98)
at org.drools.compiler.PackageBuilder.<init>(PackageBuilder.java:124)
at org.drools.compiler.PackageBuilder.<init>(PackageBuilder.java:86)
at com.sample.DecisionTableTest.readDecisionTable(DecisionTableTest.java:58)
at com.sample.DecisionTableTest.main(DecisionTableTest.java:35)
Caused by: java.lang.RuntimeException: The Eclipse JDT Core jar is not in the classpath
at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.setCompiler(JavaDialectConfiguration.java:91)
at org.drools.rule.builder.dialect.java.JavaDialectConfiguration.init(JavaDialectConfiguration.java:52)
at org.drools.compiler.PackageBuilderConfiguration.addDialect(PackageBuilderConfiguration.java:156)
... 7 more

原因是缺少包：org.eclipse.jdt.core_3.5.2.v_981_R35x.jar

加上后出现另一个错误： wrong class format

Exception in thread "main" java.lang.RuntimeException: wrong class format

jboss7运行在jdk8中，drtools版本为为5.3.1，因为drtools6以下不兼容JDK8，所以有两种解决方法：换JDK、升级drtools或者升级jdt core版本，第一次涉及项目方案设计不可行，我试比较简单的第三种，将org.eclipse.jdt.core_3.5.2.v_981_R35x.jar换成org.eclipse.jdt.core-3.8.2.v20130121.jar，再次运行后没有报错