如果您的抽象类包含具有业务价值的具体功能，那么我通常会通过创建一个测试双存根来直接测试它，或者使用一个模拟框架来为我做这件事。我选择哪一个很大程度上取决于我是否需要编写抽象方法的特定于测试的实现。

我需要这样做的最常见的场景是当我使用模板方法模式时，例如当我正在构建某种将由第三方使用的可扩展框架时。在本例中，抽象类定义了我想要测试的算法，因此测试抽象基类比测试特定实现更有意义。

然而，我认为重要的是这些测试应该只关注真实业务逻辑的具体实现;您不应该单元测试抽象类的实现细节，因为您最终会得到脆弱的测试。

遵循@patrick-desjardins的回答，我实现了抽象和它的实现类@Test，如下所示:

抽象类- ABC.java

import java.util.ArrayList;
import java.util.List;

public abstract class ABC {

    abstract String sayHello();

    public List<String> getList() {
        final List<String> defaultList = new ArrayList<>();
        defaultList.add("abstract class");
        return defaultList;
    }
}

由于抽象类不能被实例化，但它们可以被子类化，具体类DEF.java如下:

public class DEF extends ABC {

    @Override
    public String sayHello() {
        return "Hello!";
    }
}

测试类来测试抽象方法和非抽象方法:

import org.junit.Before;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.empty;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.Matchers.contains;
import java.util.Collection;
import java.util.List;
import static org.hamcrest.Matchers.equalTo;

import org.junit.Test;

public class DEFTest {

    private DEF def;

    @Before
    public void setup() {
        def = new DEF();
    }

    @Test
    public void add(){
        String result = def.sayHello();
        assertThat(result, is(equalTo("Hello!")));
    }

    @Test
    public void getList(){
        List<String> result = def.getList();
        assertThat((Collection<String>) result, is(not(empty())));
        assertThat(result, contains("abstract class"));
    }
}

首先，如果抽象类包含一些具体的方法，我认为你应该这样做，考虑这个例子

 public abstract class A 

 {

    public boolean method 1
    {
        // concrete method which we have to test.

    }


 }


 class B extends class A

 {

      @override
      public boolean method 1
      {
        // override same method as above.

      }


 } 


  class Test_A 

  {

    private static B b;  // reference object of the class B

    @Before
    public void init()

      {

      b = new B ();    

      }

     @Test
     public void Test_method 1

       {

       b.method 1; // use some assertion statements.

       }

   }

如果抽象类适合于您的实现，则测试(如上所述)派生的具体类。你的假设是正确的。

为了避免将来的混乱，请注意这个具体的测试类不是模拟的，而是假的。

严格来说，mock由以下特征定义:

A mock is used in place of each and every dependency of the subject class being tested. A mock is a pseudo-implementation of an interface (you may recall that as a general rule, dependencies should be declared as interfaces; testability is one primary reason for this) Behaviors of the mock's interface members -- whether methods or properties -- are supplied at test-time (again, by use of a mocking framework). This way, you avoid coupling of the implementation being tested with the implementation of its dependencies (which should all have their own discrete tests).

one way is to write an abstract test case that corresponds to your abstract class, then write concrete test cases that subclass your abstract test case. do this for each concrete subclass of your original abstract class (i.e. your test case hierarchy mirrors your class hierarchy). see Test an interface in the junit recipies book: http://safari.informit.com/9781932394238/ch02lev1sec6. https://www.manning.com/books/junit-recipes or https://www.amazon.com/JUnit-Recipes-Practical-Methods-Programmer/dp/1932394230 if you don't have a safari account.

也可以在xUnit模式中看到Testcase超类:http://xunitpatterns.com/Testcase%20Superclass.html

编写一个Mock对象，并仅用于测试。它们通常是非常非常小的(继承自抽象类)，而不是更多。然后，在你的单元测试中，你可以调用你想测试的抽象方法。

您应该测试包含一些逻辑的抽象类，就像您拥有的所有其他类一样。