为什么用Weka for java调用buildClassifier时会出现运行时异常

Question

我用java和我使用weka的默认contact-lens.arff数据集。

我已经完成了代码，它运行得很好，只有一个例外。

import weka.core.Instances;
import weka.classifiers.rules.OneR;
import weka.classifiers.trees.J48;
import weka.classifiers.bayes.NaiveBayes;
/*
~ some codes ~
*/
static OneR or_lens = new OneR(); 
static J48 tree_lens=new J48(); 
static NaiveBayes nb_lens = new NaiveBayes(); 

static OneR or_weather = new OneR();
static J48 tree_weather=new J48();
static NaiveBayes nb_weather = new NaiveBayes(); 

public static void lens_learning(Instances lens_data) {

try {
or_lens.buildClassifier(lens_data); // occur exception
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
/*
~ some codes ~
*/

java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @4dcbadb4
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354)
at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297)
at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199)
at java.base/java.lang.reflect.Method.setAccessible(Method.java:193)
at weka.core.WekaPackageClassLoaderManager.injectClasses(WekaPackageClassLoaderManager.java:792)
at weka.core.WekaPackageClassLoaderManager.injectAllClassesInFromStream(WekaPackageClassLoaderManager.java:690)
at weka.core.WekaPackageClassLoaderManager.injectMTJCoreClasses(WekaPackageClassLoaderManager.java:118)
at weka.core.WekaPackageManager.<clinit>(WekaPackageManager.java:255)
at weka.core.ResourceUtils.readProperties(ResourceUtils.java:241)
at weka.core.ResourceUtils.readProperties(ResourceUtils.java:184)
at weka.core.Utils.readProperties(Utils.java:183)
at weka.core.Capabilities.<clinit>(Capabilities.java:104)
at weka.classifiers.AbstractClassifier.getCapabilities(AbstractClassifier.java:509)
at weka.classifiers.rules.OneR.getCapabilities(OneR.java:289)
at weka.classifiers.rules.OneR.buildClassifier(OneR.java:317)
at hw2.Hw2.lens_learning(Hw2.java:25)
at hw2.Hw2.main(Hw2.java:102)

发生此运行时异常后，程序运行平稳。

但是，我想隐藏或删除这个异常字符串。

我使用jdk-17.0.1。

1. 为什么buildClassifier会出现此异常？

2. 如何隐藏此异常字符串？try ... catch ...无法隐藏它们：，(

Answer 1

在编写本文时，Weka的包管理器不能与Java 16或更高版本一起工作(由于低级类注入(。请改用Java 11。