Package com.google.gerrit.server.plugincontext

Class PluginItemContext<T>

java.lang.Object

com.google.gerrit.server.plugincontext.PluginItemContext<T>

public class PluginItemContext<T>
extends Object

Context to invoke an extension from a DynamicItem.

When the plugin extension is invoked a logging tag with the plugin name is set. This way any errors that are triggered by the plugin extension (even if they happen in Gerrit code which is called by the plugin extension) can be easily attributed to the plugin.

The run* methods execute an extension but don't deliver a result back to the caller. Exceptions can be caught and logged.

The call* methods execute an extension and deliver a result back to the caller.

Example if all exceptions should be caught and logged:

 fooPluginItemContext.run(foo -> foo.doFoo());
 

Example if all exceptions, but one, should be caught and logged:

 try {
   fooPluginItemContext.run(foo -> foo.doFoo(), MyException.class);
 } catch (MyException e) {
   // handle the exception
 }
 

Example if return values should be handled:

 Object result = fooPluginItemContext.call(foo -> foo.getFoo());
 

Example if return values and a single exception should be handled:

 Object result;
 try {
   result = fooPluginItemContext.call(foo -> foo.getFoo(), MyException.class);
 } catch (MyException e) {
   // handle the exception
 }
 

Example if several exceptions should be handled:

 try (TraceContext traceContext = PluginContext.newTrace(fooDynamicItem.getEntry())) {
   fooDynamicItem.get().doFoo();
 } catch (MyException1 | MyException2 | MyException3 e) {
   // handle the exception
 }
 

Constructor Summary

Constructors

Constructor	Description
PluginItemContext(DynamicItem<T> dynamicItem, PluginContext.PluginMetrics pluginMetrics)

Method Summary

Modifier and Type	Method	Description
<R,X extends Exception> R	call(PluginContext.CheckedExtensionImplFunction<T,R,X> checkedExtensionImplFunction, Class<X> exceptionClass)	Calls the plugin extension of the item and returns the result from the plugin extension call.
<R> R	call(PluginContext.ExtensionImplFunction<T,R> extensionImplFunction)	Calls the plugin extension of the item and returns the result from the plugin extension call.
String	getPluginName()	Returns the name of the plugin that registered the extension.
boolean	hasImplementation()	Checks if an implementation for this extension point has been registered.
void	run(PluginContext.ExtensionImplConsumer<T> extensionImplConsumer)	Invokes the plugin extension of the item.
<X extends Exception> void	run(PluginContext.ExtensionImplConsumer<T> extensionImplConsumer, Class<X> exceptionClass)	Invokes the plugin extension of the item.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PluginItemContext

@Inject
public PluginItemContext(DynamicItem<T> dynamicItem,
                         PluginContext.PluginMetrics pluginMetrics)

Method Detail

hasImplementation

public boolean hasImplementation()

Checks if an implementation for this extension point has been registered.

Returns:

true if an implementation for this extension point has been registered, otherwise false

getPluginName

public String getPluginName()

Returns the name of the plugin that registered the extension.

Returns:

the plugin name, null if no implementation is registered for this extension point

run

public void run(PluginContext.ExtensionImplConsumer<T> extensionImplConsumer)

Invokes the plugin extension of the item. All exceptions from the plugin extension are caught and logged.

The consumer gets the extension implementation provided that should be invoked.

No-op if no implementation is registered for this extension point.

Parameters:

extensionImplConsumer - consumer that invokes the extension

run

public <X extends Exception> void run(PluginContext.ExtensionImplConsumer<T> extensionImplConsumer,
                                      Class<X> exceptionClass)
                               throws X extends Exception

Invokes the plugin extension of the item. All exceptions from the plugin extension are caught and logged.

The consumer gets the extension implementation provided that should be invoked.

No-op if no implementation is registered for this extension point.

Parameters:

extensionImplConsumer - consumer that invokes the extension

exceptionClass - type of the exceptions that should be thrown

Throws:

X - expected exception from the plugin extension

X extends Exception

call

public <R> R call(PluginContext.ExtensionImplFunction<T,R> extensionImplFunction)

Calls the plugin extension of the item and returns the result from the plugin extension call.

The function gets the extension implementation provided that should be invoked.

Fails with IllegalStateException if no implementation is registered for the item.

Parameters:

extensionImplFunction - function that invokes the extension

Returns:

the result from the plugin extension

Throws:

IllegalStateException - if no implementation is registered for the item

call

public <R,X extends Exception> R call(PluginContext.CheckedExtensionImplFunction<T,R,X> checkedExtensionImplFunction,
                                            Class<X> exceptionClass)
                                     throws X extends Exception

Calls the plugin extension of the item and returns the result from the plugin extension call. Exceptions of the specified type are thrown and must be handled by the caller.

The function gets the extension implementation provided that should be invoked.

Fails with IllegalStateException if no implementation is registered for the item.

Parameters:

checkedExtensionImplFunction - function that invokes the extension

exceptionClass - type of the exceptions that should be thrown

Returns:

the result from the plugin extension

Throws:

X - expected exception from the plugin extension

IllegalStateException - if no implementation is registered for the item

X extends Exception