Java Android上下文在测试时不会被嘲笑

在这种结构中测试

子类

时遇到问题，我必须将

活动

的上下文下放到

文件使用工具

-类中，在该类中我编写和读取有关

子类

和

超类

状态的数据

public class FragmentA extends Fragment {
    SubClass = new SubClass(getActivity()); //Context from getActivity()
}

public class SubClass extends SuperClass {
   public SubClass(Context ctx) {
      super(ctx);
      line = "hello world";

      //file doesn't exist yet even thought we have created File object in 
      //FileUsageTools constructor
      if (!filer.file.exists()) {

         filer.saveFile(this);
      }
   }
}

public class SuperClass {
    String line;
    public SuperClass(Context ctx) {
       FileUsageTool filer = new FileUsageTool(ctx);
    }
}

public class FileUsageTool {
   Context context;
   File file;

   FileUsageTool(Context ctx) {
       context = ctx;
       file = new File(ctx.getFilesDir(), "asd.txt");
   }

   saveFile(SuperClass spr) {
        PrintWriter writer = new PrintWriter(new BufferedWriter(new FileWriter(file)));
        writer.println(spr.line);
        writer.close();
   }
   }

在class

FileUsageTool

中，我必须使用上下文来创建一个文件并对其进行写入<将在

超类

和

子类

中调用code>saveToFile

public class FragmentA extends Fragment {
    SubClass = new SubClass(getActivity()); //Context from getActivity()
}

public class SubClass extends SuperClass {
   public SubClass(Context ctx) {
      super(ctx);
      line = "hello world";

      //file doesn't exist yet even thought we have created File object in 
      //FileUsageTools constructor
      if (!filer.file.exists()) {

         filer.saveFile(this);
      }
   }
}

public class SuperClass {
    String line;
    public SuperClass(Context ctx) {
       FileUsageTool filer = new FileUsageTool(ctx);
    }
}

public class FileUsageTool {
   Context context;
   File file;

   FileUsageTool(Context ctx) {
       context = ctx;
       file = new File(ctx.getFilesDir(), "asd.txt");
   }

   saveFile(SuperClass spr) {
        PrintWriter writer = new PrintWriter(new BufferedWriter(new FileWriter(file)));
        writer.println(spr.line);
        writer.close();
   }
   }

但是当我想测试

子类

和mock

上下文

和

FileUsageTool

类时

@RunWith(MockitoJUnitRunner.class)
public class SubClassTest {

   @Mock
   private Context mockContext;
   @Mock
   private FileUsageTool mockFileUsageTool;
   @InjectMocks
   private SubClass subClass = new SubClass(mockContext);

   public testCase() {
      assertEquals(subClass.line == "hello world");
   }

---

当我运行测试时，即使关闭了

mockFileUsageTool

，我仍然会在

if（！filer.file.exists（））

处获取

NullPointerException

。问题可能是在模拟或其他方面。

我认为这是因为您在初始化中使用了上下文

试试这个

  @RunWith(MockitoJUnitRunner.class)              public class SubClassTest { 
  @Mock private Context mockContext;                  @Mock private FileUsageTool  mockFileUsageTool; 

@InjectMock私有子类子类

  @override
  protected void setUp() {
     subClass = new SubClass(mockContext)
 }

  public testCase() { 
    assertEquals(subClass.line == "hello world"); 

}