Elasticsearch JAR 地狱错误

Question

我使用 Elasticsearch Java API 创建了一个 Java 文件。在 NetBeans 中，一切正常。

但是，我开始收到以下错误：

org/elasticsearch/plugins/PluginsService.java:342:in `loadBundles': java.lang.IllegalStateException: failed to load bundle [file:/D:/ELK-2.0/elasticsearch-2.0.0/plugins/license/license-2.0.0.jar, file:/D:/ELK-2.0/elasticsearch-2.0.0/plugins/license/license-core-2.0.0.jar, file:/D:/ELK-2.0/elasticsearch-2.0.0/plugins/license/license-plugin-api-2.0.0.jar, file:/D:/ELK-2.0/elasticsearch-2.0.0/plugins/marvel-agent/marvel-agent-2.0.0.jar] due to jar hell
        from org/elasticsearch/plugins/PluginsService.java:113:in `<init>'
        from org/elasticsearch/node/Node.java:144:in `<init>'
        from org/elasticsearch/node/NodeBuilder.java:145:in `build'
        from spamdetection/SpamDetection.java:63:in `client'
        from spamdetection/SpamDetection.java:30:in `SpammerDetector'
        from java/lang/reflect/Method.java:497:in `invoke'
        from spam.rb:53:in `(root)'
        from spam.rb:53:in `(root)'
Caused by:
JarHell.java:120:in `parseClassPath': java.lang.IllegalStateException: Classpath should not contain empty elements! (outdated shell script from a previous version?) classpath=''
        from JarHell.java:95:in `parseClassPath'
        from PluginsService.java:338:in `loadBundles'
        from PluginsService.java:113:in `<init>'
        from Node.java:144:in `<init>'
        from NodeBuilder.java:145:in `build'
        from SpamDetection.java:63:in `client'
        from SpamDetection.java:30:in `SpammerDetector'
        from NativeMethodAccessorImpl.java:-2:in `invoke0'
        from NativeMethodAccessorImpl.java:62:in `invoke'
        from DelegatingMethodAccessorImpl.java:43:in `invoke'
        from Method.java:497:in `invoke'
        from JavaMethod.java:451:in `invokeDirectWithExceptionHandling'
        from JavaMethod.java:312:in `invokeDirect'
        from InstanceMethodInvoker.java:45:in `call'
        from CachingCallSite.java:326:in `cacheAndCall'
        from CachingCallSite.java:170:in `call'
        from spam.rb:53:in `__file__'
        from spam.rb:-1:in `load'
        from Ruby.java:857:in `runScript'
        from Ruby.java:850:in `runScript'
        from Ruby.java:729:in `runNormally'
        from Ruby.java:578:in `runFromMain'
        from Main.java:395:in `doRunFromMain'
        from Main.java:290:in `internalRun'
        from Main.java:217:in `run'
        from Main.java:197:in `main'

尝试从 JRuby 调用我的 Java JAR 文件时。是什么导致了这个错误？

Answer 1

您可以在您的src/test/java 中创建一个名为org.elasticsearch.bootstrap 的包，并将此类放入其中：

package org.elasticsearch.bootstrap;
import java.net.URL;
public class JarHell {
    private JarHell() {}
    public static void checkJarHell() throws Exception {}
    public static void checkJarHell(URL urls[]) throws Exception {}
    public static void checkVersionFormat(String targetVersion) {}
    public static void checkJavaVersion(String resource, String targetVersion) {}
    public static URL[] parseClassPath() {return new URL[]{};}
}

这样做的好处是使用节点构建器初始化节点的生产代码可以保持干净，只有在单元测试中禁用 jar hell 检查。

Answer 2

您现在可以通过tests.jarhell.check 属性在测试期间disable“jar hell”检查。

Answer 3

如果您在运行单元测试时遇到“jar hell”错误，请遵循 hack 处理它 - 同意这不是一种优雅的方式。

String originalClassPath = System.getProperty("java.class.path");
  String[] classPathEntries = originalClassPath.split(";");
  StringBuilder esClasspath = new StringBuilder();
       for (String entry : classPathEntries) {
           if (entry.contains("elasticsearch") || entry.contains("lucene")) {
               esClasspath.append(entry);
               esClasspath.append(";");
           }
       }
  System.setProperty("java.class.path", esClasspath.toString());
  node = nodeBuilder().local(true).settings(settings).node();
  System.setProperty("java.class.path", originalClassPath);

Answer 4

我迟到了，但我认为我的答案可能会在将来对其他人有所帮助，这就是我发布它的原因。

我认为正确的解决方案是找到根本原因并排除产生 jar hell 的库，而不是隐藏问题。例如，就我而言，我有以下重复的库：

Caused by: java.lang.IllegalStateException: jar hell!
class: org.hamcrest.BaseDescription
jar1: C:\Users\Yeikel\.m2\repository\org\hamcrest\hamcrest-all\1.3\hamcrest-all-1.3.jar
jar2: C:\Users\Yeikel\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar
        at org.elasticsearch.bootstrap.JarHell.checkClass(JarHell.java:275)
        at org.elasticsearch.bootstrap.JarHell.checkJarHell(JarHell.java:192)
        at org.elasticsearch.bootstrap.JarHell.checkJarHell(JarHell.java:89)
        at org.elasticsearch.bootstrap.BootstrapForTesting.<clinit>(BootstrapForTesting.java:90)

我为解决这个问题所做的只是找到重复项并将其从我的库中排除。在这种情况下，该库也与 JUnit 捆绑在一起

<dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.hamcrest</groupId>
                    <artifactId>hamcrest-core</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

Answer 5

由于 elasticsearch 7.14.0 JarHell 类已移至 org.elasticsearch.jdk 包。要在 Elasticsearch 版本 >= 7.14 中禁用 jar hell 检查，只需在 org.elasticsearch.jdk 包中创建以下类。

package org.elasticsearch.jdk;

import java.net.URL;
import java.util.HashSet;
import java.util.Set;
import java.util.function.Consumer;

public class JarHell {
    private JarHell() {}

    public static void checkJarHell(Set<URL> urls, Consumer<String> output) throws Exception {}

    public static void checkJarHell(Consumer<String> output) {}

    public static void checkVersionFormat(String targetVersion) {}

    public static void checkJavaVersion(String resource, String targetVersion) {}

    public static Set<URL> parseClassPath() {
        return new HashSet<>();
    }

    static Set<URL> parseClassPath(String classPath) {
        return new HashSet<>();
    }
}