| Name | Description | Type | Package | Framework |
| Base64 | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| ByteUtils | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| Cache | Interface | org.apache.solr.common.util | Apache Solr Lucene | |
| ContentStream | Interface | org.apache.solr.common.util | Apache Solr Lucene | |
| ContentStreamBase | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| ContentStreamBase .ByteArrayStream | Class | org.apache.solr.common.util.ContentStreamBase | Apache Solr Lucene | |
| ContentStreamBase .FileStream | Class | org.apache.solr.common.util.ContentStreamBase | Apache Solr Lucene | |
| ContentStreamBase .StringStream | Class | org.apache.solr.common.util.ContentStreamBase | Apache Solr Lucene | |
| ContentStreamBase .URLStream | Construct a ContentStream from a URL This uses a URLConnection to get the content stream | Class | org.apache.solr.common.util.ContentStreamBase | Apache Solr Lucene |
| DataInputInputStream | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| DateUtil | This class has some code from HttpClient DateUtil. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| ExecutorUtil | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| ExecutorUtil .InheritableThreadLocalProvider | Any class which wants to carry forward the threadlocal values to the threads run by threadpools must implement this interface and the implementation should be | Interface | org.apache.solr.common.util.ExecutorUtil | Apache Solr Lucene |
| ExecutorUtil .MDCAwareThreadPoolExecutor | Class | org.apache.solr.common.util.ExecutorUtil | Apache Solr Lucene | |
| FastInputStream | Single threaded buffered InputStream Internal Solr use only, subject to change. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| FastOutputStream | Single threaded buffered OutputStream Internal Solr use only, subject to change. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| Hash | Fast, well distributed, cross-platform hash functions. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| Hash .LongPair | Class | org.apache.solr.common.util.Hash | Apache Solr Lucene | |
| IOUtils | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| IteratorChain | Chain several Iterators, so that this iterates over all of them in sequence. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| JavaBinCodec | The class is designed to optimaly serialize/deserialize any supported types in Solr response. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| JavaBinCodec .ObjectResolver | Interface | org.apache.solr.common.util.JavaBinCodec | Apache Solr Lucene | |
| JavaBinCodec .StringBytes | Class | org.apache.solr.common.util.JavaBinCodec | Apache Solr Lucene | |
| JavaBinCodec .StringCache | Class | org.apache.solr.common.util.JavaBinCodec | Apache Solr Lucene | |
| JavaBinCodec .WritableDocFields | Interface | org.apache.solr.common.util.JavaBinCodec | Apache Solr Lucene | |
| JsonRecordReader | A Streaming parser for json to emit one record at a time. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| JsonRecordReader .Handler | Interface | org.apache.solr.common.util.JsonRecordReader | Apache Solr Lucene | |
| NamedList | A simple container class for modeling an ordered list of name/value pairs. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| NamedList .NamedListEntry | Helper class implementing Map. | Class | org.apache.solr.common.util.NamedList | Apache Solr Lucene |
| ObjectReleaseTracker | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| Pair | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| RetryUtil | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| SimpleOrderedMap | SimpleOrderedMap is a NamedList where access by key is more important than maintaining order when it comes to representing the | Class | org.apache.solr.common.util | Apache Solr Lucene |
| SolrjNamedThreadFactory | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| StrUtils | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| SuppressForbidden | Annotation to suppress forbidden-apis errors inside a whole class, a method, or a field. | Class | org.apache.solr.common.util | Apache Solr Lucene |
| URLUtil | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| Utils | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| XML | Class | org.apache.solr.common.util | Apache Solr Lucene | |
| XMLErrorLogger | Class | org.apache.solr.common.util | Apache Solr Lucene | |