Question

当我在kie workbench中创建引导决策表时，我会在执行无状态或有状态kie会话时获得空指针异常。更具体地说，我使用drools 7，并使用java和grizzly公开了一个简单的休息服务。当我使用简单的drl文件时，我的规则正在触发并正确执行，但是当我使用我的jar中的决策表部署时，我得到了NPE。

Java代码：

 public CustomerDto executeStatelessPOC(final String param,
       final StatelessKieSession kSession ,final KieServices kServices) {
    //Myexample is just the entry fact
    InputDTO example = new InputDTO();
    example.setField1(param);       

    CustomerDto response = new CustomerDto();
    try {            

        KieCommands kieCommands = kServices.getCommands();
        List<Command> cmds = new ArrayList<Command>();
        cmds.add(kieCommands.newInsert(example));
        cmds.add(kieCommands.newInsert(response, "customerResponse"));           

        //Execute rules with facts provided before            
        ExecutionResults results = kSession.execute(kieCommands.newBatchExecution(cmds));
        //Get the response as part of the results
        response = (CustomerDto) results.getValue("customerResponse");
        return response;

    } catch (Exception e) {
        System.out.println("Exception e: " + e.toString());
        System.out.println("Exception e: " + Arrays.toString(e.getStackTrace()));
    }
    return response;
}

指导决策表的源代码：

package gr.maven.test.testbuildinmaven;

//来自行号：1 规则＆＃34;第1行TestDecisionTable＆＃34; 方言＆＃34; mvel＆＃34; 什么时候输入：InputDTO（field1 ==＆＃34; Test1＆＃34;）然后 CustomerDto fact0 = new CustomerDto（）; fact0.setCustomerMessage（＆＃34; yesss＆＃34;）; insertLogical（fact0）; 端

//来自行号：2 规则＆＃34;第2行TestDecisionTable＆＃34; 方言＆＃34; mvel＆＃34; 什么时候输入：InputDTO（field1 ==＆＃34; Test2＆＃34;）然后 CustomerDto fact0 = new CustomerDto（）; fact0.setCustomerMessage（＆＃34; yes2＆＃34;）; insertLogical（fact0）; 端

//来自行号：3 规则＆＃34;第3行TestDecisionTable＆＃34; 方言＆＃34; mvel＆＃34; 什么时候输入：InputDTO（field1 ==＆＃34; Test3＆＃34;）然后 CustomerDto fact0 = new CustomerDto（）; fact0.setCustomerMessage（＆＃34; yesss＆＃34;）; insertLogical（fact0）; 端

例外：

WARNING: The following warnings have been detected: WARNING: Unknown HK2 failure detected:

MultiException堆栈1 of 2 java.lang.ExceptionInInitializerError at sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native Method） at sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:62） at sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45） at java.lang.reflect.Constructor.newInstance（Constructor.java:423）在org.glassfish.hk2.utilities.reflection.ReflectionHelper.makeMe（ReflectionHelper.java:1129）在org.jvnet.hk2.internal.ClazzCreator.createMe(ClazzCreator.java:274）在org.jvnet.hk2.internal.ClazzCreator.create(ClazzCreator.java:368） at org.jvnet.hk2.internal.SystemDescriptor.create（SystemDescriptor.java:471）在org.glassfish.jersey.process.internal.RequestScope.findOrCreate（RequestScope.java:162） at org.jvnet.hk2.internal.Utilities.createService（Utilities.java:2064） at org.jvnet.hk2.internal.ServiceLocatorImpl.internalGetService（ServiceLocatorImpl.java:711） at org.jvnet.hk2.internal.ServiceLocatorImpl.getService（ServiceLocatorImpl.java:653）在org.glassfish.jersey.internal.inject.Injections.getOrCreate（Injections.java:169） at org.glassfish.jersey.server.model.MethodHandler $ ClassBasedMethodHandler.getInstance（MethodHandler.java:185）在org.glassfish.jersey.server.internal.routing.PushMethodHandlerRouter.apply（PushMethodHandlerRouter.java:74）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:109）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage.apply（RoutingStage.java:92）在org.glassfish.jersey.server.internal.routing.RoutingStage.apply（RoutingStage.java:61）在org.glassfish.jersey.process.internal.Stages.process（Stages.java:197）在org.glassfish.jersey.server.ServerRuntime $ 2.run（ServerRuntime.java:297）在org.glassfish.jersey.internal.Errors $ 1.call（Errors.java:271）在org.glassfish.jersey.internal.Errors $ 1.call（Errors.java:267）在org.glassfish.jersey.internal.Errors.process（Errors.java:315）在org.glassfish.jersey.internal.Errors.process（Errors.java:297）在org.glassfish.jersey.internal.Errors.process（Errors.java:267）在org.glassfish.jersey.process.internal.RequestScope.runInScope（RequestScope.java:317）在org.glassfish.jersey.server.ServerRuntime.process（ServerRuntime.java:288）在org.glassfish.jersey.server.ApplicationHandler.handle（ApplicationHandler.java:1110）在org.glassfish.jersey.grizzly2.httpserver.GrizzlyHttpContainer.service（GrizzlyHttpContainer.java:381）在org.glassfish.grizzly.http.server.HttpHandler $ 1.run（HttpHandler.java:219）在org.glassfish.grizzly.threadpool.AbstractThreadPool $ Worker.doWork（AbstractThreadPool.java:565）在org.glassfish.grizzly.threadpool.AbstractThreadPool $ Worker.run（AbstractThreadPool.java:545）在java.lang.Thread.run（Thread.java:748）引起：java.lang.NullPointerException at org.drools.compiler.builder.impl.KnowledgeBuilderImpl.guidedDecisionTableToPackageDescr（KnowledgeBuilderImpl.java:411） at org.drools.compiler.builder.impl.CompositeKnowledgeBuilderImpl $ ResourceToPkgDescrMapper.lambda $ static $ 6（CompositeKnowledgeBuilderImpl.java:309） at org.drools.compiler.builder.impl.CompositeKnowledgeBuilderImpl.buildResource（CompositeKnowledgeBuilderImpl.java:187） at org.drools.compiler.builder.impl.CompositeKnowledgeBuilderImpl.buildPackageDescr（CompositeKnowledgeBuilderImpl.java:176） at org.drools.compiler.builder.impl.CompositeKnowledgeBuilderImpl.buildPackages（CompositeKnowledgeBuilderImpl.java:109） at org.drools.compiler.builder.impl.CompositeKnowledgeBuilderImpl.build（CompositeKnowledgeBuilderImpl.java:99） at org.drools.compiler.kie.builder.impl.AbstractKieProject.buildKnowledgePackages（AbstractKieProject.java:247）在org.drools.compiler.kie.builder.impl.AbstractKieModule.createKieBase（AbstractKieModule.java:210） at org.drools.compiler.kie.builder.impl.KieContainerImpl.createKieBase（KieContainerImpl.java:389）在org.drools.compiler.kie.builder.impl.KieContainerImpl.getKieBase（KieContainerImpl.java:357） at org.drools.compiler.kie.builder.impl.KieContainerImpl.newStatelessKieSession（KieContainerImpl.java:550） at org.drools.compiler.kie.builder.impl.KieContainerImpl.newStatelessKieSession（KieContainerImpl.java:460） at org.drools.compiler.kie.builder.impl.KieContainerImpl.newStatelessKieSession（KieContainerImpl.java:455）在com.mycompany.grizzlypoc.rest.services.StatelessService。（StatelessService.java:37） ......还有37个 MultiException堆栈2 of 2 java.lang.IllegalStateException：无法执行操作：在com.mycompany.grizzlypoc.rest.services.StatelessService上创建在org.jvnet.hk2.internal.ClazzCreator.create(ClazzCreator.java:395） at org.jvnet.hk2.internal.SystemDescriptor.create（SystemDescriptor.java:471）在org.glassfish.jersey.process.internal.RequestScope.findOrCreate（RequestScope.java:162） at org.jvnet.hk2.internal.Utilities.createService（Utilities.java:2064） at org.jvnet.hk2.internal.ServiceLocatorImpl.internalGetService（ServiceLocatorImpl.java:711） at org.jvnet.hk2.internal.ServiceLocatorImpl.getService（ServiceLocatorImpl.java:653）在org.glassfish.jersey.internal.inject.Injections.getOrCreate（Injections.java:169） at org.glassfish.jersey.server.model.MethodHandler $ ClassBasedMethodHandler.getInstance（MethodHandler.java:185）在org.glassfish.jersey.server.internal.routing.PushMethodHandlerRouter.apply（PushMethodHandlerRouter.java:74）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:109）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage._apply（RoutingStage.java:112）在org.glassfish.jersey.server.internal.routing.RoutingStage.apply（RoutingStage.java:92）在org.glassfish.jersey.server.internal.routing.RoutingStage.apply（RoutingStage.java:61）在org.glassfish.jersey.process.internal.Stages.process（Stages.java:197）在org.glassfish.jersey.server.ServerRuntime $ 2.run（ServerRuntime.java:297）在org.glassfish.jersey.internal.Errors $ 1.call（Errors.java:271）在org.glassfish.jersey.internal.Errors $ 1.call（Errors.java:267）在org.glassfish.jersey.internal.Errors.process（Errors.java:315）在org.glassfish.jersey.internal.Errors.process（Errors.java:297）在org.glassfish.jersey.internal.Errors.process（Errors.java:267）在org.glassfish.jersey.process.internal.RequestScope.runInScope（RequestScope.java:317）在org.glassfish.jersey.server.ServerRuntime.process（ServerRuntime.java:288）在org.glassfish.jersey.server.ApplicationHandler.handle（ApplicationHandler.java:1110）在org.glassfish.jersey.grizzly2.httpserver.GrizzlyHttpContainer.service（GrizzlyHttpContainer.java:381）在org.glassfish.grizzly.http.server.HttpHandler $ 1.run（HttpHandler.java:219）在org.glassfish.grizzly.threadpool.AbstractThreadPool $ Worker.doWork（AbstractThreadPool.java:565）在org.glassfish.grizzly.threadpool.AbstractThreadPool $ Worker.run（AbstractThreadPool.java:545）在java.lang.Thread.run（Thread.java:748）

Answer 1

在我的POM xml中使用此依赖项解决了问题。

   <dependency>
        <groupId>org.drools</groupId>
        <artifactId>drools-workbench-models-guided-dtable</artifactId>
        <version>7.7.0.Final</version>
    </dependency>

Answer 2

我很困惑应该更改哪个POM.xml文件（即规则方或应用方）。

今天我尝试了，得到了答案！它必须与应用程序端。

我的build.gradle如下：

buildscript {
    ext {
        drools_version = '7.7.0.Final'
    }
}
dependencies {
    compile "org.drools:drools-workbench-models-guided-dtable:$drools_version"
    compile "org.kie:kie-api:$drools_version"
}

我的kotlin项目很好。

Drools Guided Decision Table抛出空指针异常

2 个答案: