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mavensolrj

Using Solrj 5.2.1 with Maven

I created a new Maven project with solrj dependency:

<dependency>
    <groupId>org.apache.solr</groupId>
    <artifactId>solr-solrj</artifactId>
    <version>5.2.1</version>
</dependency>

It compiles correctly but if you try to use some solrj code the application crushes with the following exception:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
    at org.apache.http.impl.client.CloseableHttpClient.<init>(CloseableHttpClient.java:58)
    at org.apache.http.impl.client.AbstractHttpClient.<init>(AbstractHttpClient.java:287)
    at org.apache.http.impl.client.DefaultHttpClient.<init>(DefaultHttpClient.java:128)
    at org.apache.http.impl.client.SystemDefaultHttpClient.<init>(SystemDefaultHttpClient.java:116)
    at org.apache.solr.client.solrj.impl.HttpClientUtil.createClient(HttpClientUtil.java:117)
    at org.apache.solr.client.solrj.impl.CloudSolrClient.<init>(CloudSolrClient.java:189)
    at Main.main(Main.java:44)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 12 more
Solution

  • Solrj depends on two generic logging libraries: SLF4J and Commons Logging. Each needs some kind of real implementation to work. Adding the following dependencies (Commons Logging to SLF4J redirection and simple console-based appender) to the pom.xml resolves the issue.

    <dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>jcl-over-slf4j</artifactId>
    <version>1.7.7</version>
    <scope>runtime</scope>
</dependency>

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-simple</artifactId>
    <version>1.7.7</version>
</dependency>