JUnit4.8.2 Source Analysis-2 org.junit.runner.Request

JUnit4.8.2 source code, the most yqj2065 interest is org.junit.runner.Request, now what are the points that mean it?

① Encapsulation of junit inputs

JUNIT4 as the information Processing unit, its input is the unit test class -full of various JUNIT4 runtime labeled classes, but because of the use of reflection mechanism, JUNIT4 input is strictly one or more (group) unit test class object . The earlier version of JUnit mainly deals with a test or test-made tree, and JUNIT4 adds this concept after adding a filter/filtering and sort/sorting support. After all, the direct use of reflection mechanism according to 1.2.4 Java Annotation feed . The code can be very complex.

② isetal father?

Object-oriented. The generic parent does not know its subclasses. But here we see the counter example.

Javadoc generated in the BlueJ

When should the parent class know the subclass ? This is a problem, and I just remember having a knowntype in the data contract in WCF. The request source imports its various subclasses and uses them in a series of static methods to return the request object. Request is an abstract class that returns the object of the request (subclass) through a static method, and how much hatred it has with new. I just like it.

These static methods I don't call them static factories

public static Request AClass (CLASS<?

> Clazz)

public static Request Classwithoutsuitemethod (class<?> clazz)

public static Request classes (computer computer, Class<?> .... classes)

public static Request classes (class<?>...classes)

public static Request runner (final runner runner)

public static Request method (Class<?> clazz, String methodName) {

Description method= description.createtestdescription (clazz,methodname);

Return Request.aclass (Clazz). Filterwith (method);

}

Request.method () encapsulates a @test as a request, after all @Test is the basis. "HelloWorld unit test class TESTINJUNIT4 See source Analysis-1"

Routine 8-3 test request class Package Mytest;import org.junit.runner.*;p ublic class requestdemo{public    static void Test () throws exception{        Request rqst = Request.method (Testinjunit4.class, "add");        Result r = new Junitcore (). Run (RQST);          System.out.println (R.wassuccessful ());}    }

③request used the factory method model .

request has a factory method: Public Abstractrunner Getrunner ();

And the design of the request has a singular place: do you seem to use decorative patterns when creating objects? The request is a detailed component of component, Org.junit.internal.request.ClassRequest in decorative mode, while Filterrequest and Sortingrequest are detailed decorators ( No abstract decorator). And all of this is intended to build the runner associated with the request.

④requestusing Set-string mode

Other non-static methods of request Filterwith, Sortwith can be considered as set methods.

Examples are given in Request.method ():

Return Request.aclass (Clazz). Filterwith (method);

The types covered in this article: request and its 3 subclasses,Description; Design patterns involved: Factory method Mode, set-string mode, decorative mode .

Related types: Runner, Alldefaultpossibilitiesbuilder, filter, and so on.

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JUnit4.8.2 Source Analysis-2 org.junit.runner.Request