LauncherInterceptor

All Known Implementing Classes:

ClasspathAlignmentCheckingLauncherInterceptor
```
@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

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

- Method Detail
  - 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.