| Name | Description | Type | Package | Framework |
| AppenderAttachable | Interface for attaching appenders to objects. | Interface | org.apache.log4j.spi | Apache Log4j |
| Configurator | Interface | org.apache.log4j.spi | Apache Log4j | |
| DefaultRepositorySelector | Class | org.apache.log4j.spi | Apache Log4j | |
| ErrorCode | This interface defines commonly encoutered error codes. | Interface | org.apache.log4j.spi | Apache Log4j |
| ErrorHandler | Appenders may delegate their error handling to Error handling is a particularly tedious to get right because by | Interface | org.apache.log4j.spi | Apache Log4j |
| Filter | Users should extend this class to implement customized logging event filtering. | Class | org.apache.log4j.spi | Apache Log4j |
| HierarchyEventListener | Listen to events occuring within a Hierarchy. | Interface | org.apache.log4j.spi | Apache Log4j |
| LocationInfo | The internal representation of caller location information. | Class | org.apache.log4j.spi | Apache Log4j |
| LoggerFactory | a sub-class of Logger. | Interface | org.apache.log4j.spi | Apache Log4j |
| LoggerRepository | A LoggerRepository is used to create and retrieve Loggers. | Interface | org.apache.log4j.spi | Apache Log4j |
| LoggingEvent | The internal representation of logging events. | Class | org.apache.log4j.spi | Apache Log4j |
| NOPLogger | No-operation implementation of Logger used by NOPLoggerRepository. | Class | org.apache.log4j.spi | Apache Log4j |
| NOPLoggerRepository | No-operation implementation of LoggerRepository which is used when LogManager. | Class | org.apache.log4j.spi | Apache Log4j |
| OptionHandler | A string based interface to configure package components. | Interface | org.apache.log4j.spi | Apache Log4j |
| RendererSupport | Interface | org.apache.log4j.spi | Apache Log4j | |
| RepositorySelector | The LogManager uses one (and only one) RepositorySelector implementation to select the | Interface | org.apache.log4j.spi | Apache Log4j |
| RootCategory | Fields inherited from class org. | Class | org.apache.log4j.spi | Apache Log4j |
| RootLogger | RootLogger sits at the top of the logger hierachy. | Class | org.apache.log4j.spi | Apache Log4j |
| ThrowableInformation | ThrowableInformation is log4j's internal representation of throwables. | Class | org.apache.log4j.spi | Apache Log4j |
| ThrowableRenderer | java. | Interface | org.apache.log4j.spi | Apache Log4j |
| ThrowableRendererSupport | rendering of Throwables. | Interface | org.apache.log4j.spi | Apache Log4j |
| TriggeringEventEvaluator | when to perform an appender specific action. | Interface | org.apache.log4j.spi | Apache Log4j |
| Configurator | Interface | org.apache.log4j.spi | SLF4J | |
| ErrorHandler | Created by IntelliJ IDEA. | Class | org.apache.log4j.spi | SLF4J |
| Filter | Class | org.apache.log4j.spi | SLF4J | |
| HierarchyEventListener | Listen to events occuring within a Hierarchy. | Interface | org.apache.log4j.spi | SLF4J |
| LoggerFactory | a sub-class of Logger. | Interface | org.apache.log4j.spi | SLF4J |
| LoggerRepository | A LoggerRepository is used to create and retrieve Loggers. | Interface | org.apache.log4j.spi | SLF4J |
| LoggingEvent | Class | org.apache.log4j.spi | SLF4J | |