Module org.junit.platform.launcher

Package org.junit.platform.launcher

Interface LauncherInterceptor

@API(status=MAINTAINED,
     since="1.13.3")
public interface LauncherInterceptor

Interceptor for test discovery and execution by a Launcher in the context of a LauncherSession.

Interceptors are instantiated once per LauncherSession and closed after the session is closed. They can intercept the following invocations:

• creation of LauncherSessionListener instances registered via the ServiceLoader mechanism
• creation of Launcher instances
• calls to Launcher.discover(LauncherDiscoveryRequest), Launcher.execute(TestPlan, TestExecutionListener...), and Launcher.execute(LauncherDiscoveryRequest, TestExecutionListener...)

Implementations of this interface can be registered via the ServiceLoader mechanism by additionally setting the "junit.platform.launcher.interceptors.enabled" configuration parameter to true.

A typical use case is to create a custom ClassLoader in the constructor of the implementing class, replace the contextClassLoader of the current thread while intercepting invocations, and close the custom ClassLoader in close()

Since:

1.10

See Also:

• Launcher
• LauncherSession
• LauncherConstants.ENABLE_LAUNCHER_INTERCEPTORS

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	LauncherInterceptor.Invocation<T>	An invocation that can be intercepted.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this interceptor.
<T> T	intercept(LauncherInterceptor.Invocation<T> invocation)	Intercept the supplied invocation.

Method Details

intercept

<T> T intercept(LauncherInterceptor.Invocation<T> invocation)

Intercept the supplied invocation.

Implementations must call LauncherInterceptor.Invocation.proceed() exactly once.

Parameters:

invocation - the intercepted invocation; never null

Returns:

the result of the invocation

close

void close()

Closes this interceptor.

Any resources held by this interceptor should be released by this method.