| Name | Description | Type | Package | Framework |
| AbstractPluginLoader | An abstract super class that manages standard solr-style plugin configuration. | Class | org.apache.solr.util.plugin | Apache Solr Lucene |
| AdjustableSemaphore | Class | org.apache.solr.util | Apache Solr Lucene | |
| BoundedTreeSet | A TreeSet that ensures it never grows beyond a max size. | Class | org.apache.solr.util | Apache Solr Lucene |
| Clock | An abstraction for how time passes. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| Clock .CpuTimeClock | A clock implementation which returns the current thread's CPU time. | Class | org.apache.solr.util.stats.Clock | Apache Solr Lucene |
| Clock .UserTimeClock | A clock implementation which returns the current time in epoch nanoseconds. | Class | org.apache.solr.util.stats.Clock | Apache Solr Lucene |
| CommandOperation | Class | org.apache.solr.util | Apache Solr Lucene | |
| ConcurrentLFUCache | A LFU cache implementation based upon ConcurrentHashMap. | Class | org.apache.solr.util | Apache Solr Lucene |
| ConcurrentLFUCache .EvictionListener | Interface | org.apache.solr.util.ConcurrentLFUCache | Apache Solr Lucene | |
| ConcurrentLFUCache .Stats | Class | org.apache.solr.util.ConcurrentLFUCache | Apache Solr Lucene | |
| ConcurrentLRUCache | A LRU cache implementation based upon ConcurrentHashMap and other techniques to reduce contention and synchronization overhead to utilize multiple CPU cores more effectively. | Class | org.apache.solr.util | Apache Solr Lucene |
| ConcurrentLRUCache .EvictionListener | Interface | org.apache.solr.util.ConcurrentLRUCache | Apache Solr Lucene | |
| ConcurrentLRUCache .Stats | Class | org.apache.solr.util.ConcurrentLRUCache | Apache Solr Lucene | |
| CryptoKeys | Class | org.apache.solr.util | Apache Solr Lucene | |
| CryptoKeys .RSAKeyPair | Class | org.apache.solr.util.CryptoKeys | Apache Solr Lucene | |
| DateFormatUtil | Class | org.apache.solr.util | Apache Solr Lucene | |
| DateFormatUtil .ThreadLocalDateFormat | Class | org.apache.solr.util.DateFormatUtil | Apache Solr Lucene | |
| DateMathParser | A Simple Utility class for parsing math like strings relating to Dates. | Class | org.apache.solr.util | Apache Solr Lucene |
| DefaultSolrThreadFactory | Class | org.apache.solr.util | Apache Solr Lucene | |
| DistanceUnits | Used with a spatial field type for all distance measurements. | Class | org.apache.solr.util | Apache Solr Lucene |
| DOMUtil | Class | org.apache.solr.util | Apache Solr Lucene | |
| EmptyEntityResolver | This class provides several singletons of entity resolvers used by SAX and StAX in the Java API. | Class | org.apache.solr.util | Apache Solr Lucene |
| EWMA | An exponentially-weighted moving average. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| ExponentiallyDecayingSample | An exponentially-decaying random sample of longs. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| FastWriter | Single threaded BufferedWriter Internal Solr use only, subject to change. | Class | org.apache.solr.util | Apache Solr Lucene |
| FileUtils | Class | org.apache.solr.util | Apache Solr Lucene | |
| FSHDFSUtils | Borrowed from Apache HBase to recover an HDFS lease. | Class | org.apache.solr.util | Apache Solr Lucene |
| HdfsUtil | Class | org.apache.solr.util | Apache Solr Lucene | |
| Histogram | A metric which calculates the distribution of a value. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| HLL | A probabilistic set of hashed long elements. | Class | org.apache.solr.util.hll | Apache Solr Lucene |
| HLLType | The types of algorithm/data structure that HLL can utilize. | Class | org.apache.solr.util.hll | Apache Solr Lucene |
| IWordDeserializer | Reads 'words' of a fixed width, in sequence, from a byte array. | Interface | org.apache.solr.util.hll | Apache Solr Lucene |
| LongPriorityQueue | A native long priority queue. | Class | org.apache.solr.util | Apache Solr Lucene |
| MapInitializedPlugin | Interface | org.apache.solr.util.plugin | Apache Solr Lucene | |
| MapListener | Wraps another map, keeping track of each key that was seen via get(Object) or remove(Object). | Class | org.apache.solr.util | Apache Solr Lucene |
| MapPluginLoader | Class | org.apache.solr.util.plugin | Apache Solr Lucene | |
| Meter | A meter metric which measures mean throughput and one-, five-, and fifteen-minute exponentially-weighted moving average throughputs. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| NamedListInitializedPlugin | Interface | org.apache.solr.util.plugin | Apache Solr Lucene | |
| NamedListPluginLoader | Class | org.apache.solr.util.plugin | Apache Solr Lucene | |
| NumberUtils | Class | org.apache.solr.util | Apache Solr Lucene | |
| PivotListEntry | Enum for modeling the elements of a (nested) pivot entry as expressed in a NamedListEnum Constant Summary | Class | org.apache.solr.util | Apache Solr Lucene |
| PluginInfoInitialized | Interface | org.apache.solr.util.plugin | Apache Solr Lucene | |
| PrimUtils | Utilities for primitive Java data types. | Class | org.apache.solr.util | Apache Solr Lucene |
| PrimUtils .IntComparator | Class | org.apache.solr.util.PrimUtils | Apache Solr Lucene | |
| PropertiesInputStream | Class | org.apache.solr.util | Apache Solr Lucene | |
| PropertiesOutputStream | Class | org.apache.solr.util | Apache Solr Lucene | |
| PropertiesUtil | Breaking out some utility methods into a separate class as part of SOLR-4196. | Class | org.apache.solr.util | Apache Solr Lucene |
| RecordingJSONParser | Class | org.apache.solr.util | Apache Solr Lucene | |
| RefCounted | Keep track of a reference count on a resource and close it when the count hits zero. | Class | org.apache.solr.util | Apache Solr Lucene |
| RegexFileFilter | Class | org.apache.solr.util | Apache Solr Lucene | |
| RTimer | RTimers are started automatically when instantiated; subtimers are also started automatically when created. | Class | org.apache.solr.util | Apache Solr Lucene |
| Sample | A statistically representative sample of a data stream. | Interface | org.apache.solr.util.stats | Apache Solr Lucene |
| SimplePostTool | A simple utility class for posting raw updates to a Solr server, has a main method so it can be run on the command line. | Class | org.apache.solr.util | Apache Solr Lucene |
| SimplePostTool .BAOS | Class | org.apache.solr.util.SimplePostTool | Apache Solr Lucene | |
| Snapshot | A statistical snapshot of a Snapshot. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| SolrCLI | Command-line utility for working with Solr. | Class | org.apache.solr.util | Apache Solr Lucene |
| SolrCLI .ApiTool | Used to send an arbitrary HTTP request to a Solr API endpoint. | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene |
| SolrCLI .ConfigTool | Sends a POST to the Config API to perform a specified action. | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene |
| SolrCLI .CreateCollectionTool | Supports create_collection command in the bin/solr script. | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene |
| SolrCLI .CreateCoreTool | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene | |
| SolrCLI .CreateTool | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene | |
| SolrCLI .DeleteTool | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene | |
| SolrCLI .HealthcheckTool | Requests health information about a specific collection in SolrCloud. | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene |
| SolrCLI .RunExampleTool | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene | |
| SolrCLI .SolrCloudTool | Helps build SolrCloud aware tools by initializing a CloudSolrClient instance before running the tool. | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene |
| SolrCLI .StatusTool | Get the status of a Solr server. | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene |
| SolrCLI .Tool | Defines the interface to a Solr tool that can be run from this command-line app. | Interface | org.apache.solr.util.SolrCLI | Apache Solr Lucene |
| SolrCLI .ToolBase | Class | org.apache.solr.util.SolrCLI | Apache Solr Lucene | |
| SolrLogLayout | Class | org.apache.solr.util | Apache Solr Lucene | |
| SolrLogLayout .CoreInfo | Class | org.apache.solr.util.SolrLogLayout | Apache Solr Lucene | |
| SolrLogLayout .Method | Class | org.apache.solr.util.SolrLogLayout | Apache Solr Lucene | |
| SolrLogLayout .TG | Add this interface to a thread group and the string returned by getTag() will appear in log statements of any threads under that group. | Interface | org.apache.solr.util.SolrLogLayout | Apache Solr Lucene |
| SolrPluginUtils | Utilities that may be of use to RequestHandlers. | Class | org.apache.solr.util | Apache Solr Lucene |
| SolrPluginUtils .DisjunctionMaxQueryParser | A subclass of SolrQueryParser that supports aliasing fields for constructing DisjunctionMaxQueries. | Class | org.apache.solr.util.SolrPluginUtils | Apache Solr Lucene |
| SolrPluginUtils .DisjunctionMaxQueryParser .Alias | A simple container for storing alias infoSee Also:SolrPluginUtils. | Class | org.apache.solr.util.SolrPluginUtils.DisjunctionMaxQueryParser | Apache Solr Lucene |
| SolrPluginUtils .IdentityRegenerator | A CacheRegenerator that can be used whenever the items in the cache are not dependant on the current searcher. | Class | org.apache.solr.util.SolrPluginUtils | Apache Solr Lucene |
| SpatialUtils | Utility methods pertaining to spatial. | Class | org.apache.solr.util | Apache Solr Lucene |
| SystemIdResolver | This is a helper class to support resolving of XIncludes or other hrefs inside XML files on top of a ResourceLoader. | Class | org.apache.solr.util | Apache Solr Lucene |
| Timer | A timer metric which aggregates timing durations and provides duration statistics, plus throughput statistics via Meter. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| TimerContext | See Also:Timer. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| TimeZoneUtils | Class | org.apache.solr.util | Apache Solr Lucene | |
| TransformerProvider | Singleton that creates a Transformer for the XSLTServletFilter. | Class | org.apache.solr.util.xslt | Apache Solr Lucene |
| UniformSample | A random sample of a stream of longs. | Class | org.apache.solr.util.stats | Apache Solr Lucene |
| VersionedFile | Class | org.apache.solr.util | Apache Solr Lucene | |
| AbstractSolrTestCase | An Abstract base class that makes writing Solr JUnit tests easier Test classes that subclass this need only specify the path to the | Class | org.apache.solr.util | Apache Solr Lucene |
| BadHdfsThreadsFilter | Class | org.apache.solr.util | Apache Solr Lucene | |
| BadMrClusterThreadsFilter | Class | org.apache.solr.util | Apache Solr Lucene | |
| BadZookeeperThreadsFilter | Class | org.apache.solr.util | Apache Solr Lucene | |
| BaseTestHarness | Class | org.apache.solr.util | Apache Solr Lucene | |
| DOMUtilTestBase | Class | org.apache.solr.util | Apache Solr Lucene | |
| ExternalPaths | Some tests need to reach outside the classpath to get certain resources (e. | Class | org.apache.solr.util | Apache Solr Lucene |
| RandomMergePolicy | A MergePolicy with a no-arg constructor that proxies to a wrapped instance retrieved from LuceneTestCase. | Class | org.apache.solr.util | Apache Solr Lucene |
| ReadOnlyCoresLocator | Class | org.apache.solr.util | Apache Solr Lucene | |
| RestTestBase | Class | org.apache.solr.util | Apache Solr Lucene | |
| RestTestHarness | Class | org.apache.solr.util | Apache Solr Lucene | |
| RevertDefaultThreadHandlerRule | Class | org.apache.solr.util | Apache Solr Lucene | |
| SSLTestConfig | Class | org.apache.solr.util | Apache Solr Lucene | |
| TestHarness | This class provides a simple harness that may be useful when This class lives in the tests-framework source tree (and not in the test source | Class | org.apache.solr.util | Apache Solr Lucene |
| TestHarness .TestCoresLocator | Class | org.apache.solr.util.TestHarness | Apache Solr Lucene | |