Package com.google.gerrit.server.plugincontext

Class PluginMapEntryContext<T>

  • public class PluginMapEntryContext<T>
extends Object
    Context to invoke an extension from DynamicMap.

    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 the extension but don't deliver a result back to the caller. Exceptions can be caught and logged.

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

     Map results = new HashMap<>();
 fooPluginMapEntryContext.run(
     extension -> results.put(extension.getExportName(), extension.get().getFoo());

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

     Map results = new HashMap<>();
 try {
   fooPluginMapEntryContext.run(
     extension -> results.put(extension.getExportName(), extension.get().getFoo(),
     MyException.class);
 } catch (MyException e) {
   // handle the exception
 }

    Example if return values should be handled: 

     Object result = fooPluginMapEntryContext.call(extension -> extension.get().getFoo());

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

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

    Example if several exceptions should be handled: 

     for (Extension fooExtension : fooDynamicMap) {
   try (TraceContext traceContext = PluginContext.newTrace(fooExtension)) {
     fooExtension.get().doFoo();
   } catch (MyException1 | MyException2 | MyException3 e) {
     // handle the exception
   }
 }

    • Method Detail

      • getPluginName

        public String getPluginName()
        Returns the name of the plugin that registered this map entry.
        Returns:
        the plugin name

      • getExportName

        public String getExportName()
        Returns the export name for which this map entry was registered.
        Returns:
        the export name

      • run

        public void run​(PluginContext.ExtensionConsumer<Extension<T>> extensionConsumer)
        Invokes the plugin extension. All exceptions from the plugin extension are caught and logged.

        The consumer get the Extension provided that should be invoked. The extension provides access to the plugin name and the export name.

        Parameters:
        extensionConsumer - consumer that invokes the extension

      • run

        public <X extends Exception> void run​(PluginContext.ExtensionConsumer<Extension<T>> extensionConsumer,
                                      Class<X> exceptionClass)
                               throws X extends Exception
        Invokes the plugin extension. All exceptions from the plugin extension are caught and logged.

        The consumer get the Extension provided that should be invoked. The extension provides access to the plugin name and the export name.

        Parameters:
        extensionConsumer - 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.ExtensionFunction<Extension<T>,​R> extensionFunction)
        Calls the plugin extension and returns the result from the plugin extension call.

        The consumer get the Extension provided that should be invoked. The extension provides access to the plugin name and the export name.

        Parameters:
        extensionFunction - function that invokes the extension
        Returns:
        the result from the plugin extension

      • call

        public <R,​X extends Exception> R call​(PluginContext.CheckedExtensionFunction<Extension<T>,​R,​X> checkedExtensionFunction,
                                            Class<X> exceptionClass)
                                     throws X extends Exception
        Calls the plugin extension and returns the result from the plugin extension call. Exceptions of the specified type are thrown and must be handled by the caller.

        The consumer get the Extension provided that should be invoked. The extension provides access to the plugin name and the export name.

        Parameters:
        checkedExtensionFunction - 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
        X extends Exception