# Request handler for a function in Java

A _request handler_ is a method used to process each Java function call.

When [creating a function version](../../operations/function/version-manage.md), you specify the entry point, i.e., the function that the [runtime environment](../../concepts/runtime/index.md) calls as a handler. The entry point name consists of the name of the class containing the handler, e.g., `orgexample.Handler`.

The name of the handler file must not contain any `.` before the extension, e.g., `.handler.java`.

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At any given time, one function instance cannot handle more calls than specified in the [concurrency](../../concepts/function.md#concurrency) parameter. This allows you to use global variables without having to provide data integrity control.

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Depending on the programming model, the handler can accept and return different data. For more information about this and available ways to set a request handler, see the [Java programming model](model/index.md) section.