测试 UUID 抛出 org.mockito.exceptions.misusing.MissingMethodInvocationException

如何解决测试 UUID 抛出 org.mockito.exceptions.misusing.MissingMethodInvocationException

我有一个非常简单的测试方法：

要测试的方法：

  public static String newUuid() {
        return UUID.randomUUID().toString();
    }

我用 powermock 来测试它：

@Test
public void testNewUuid() { 
    mockStatic(UUID.class);
    when(UUID.randomUUID().toString()).thenReturn("uuid");
    assertEquals("uuid",UuidHelper.newUuid());
        
}

但是我收到以下错误：

org.mockito.exceptions.misusing.MissingMethodInvocationException: 
when() requires an argument which has to be 'a method call on a mock'.
For example:
    when(mock.getArticles()).thenReturn(articles);

Also,this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
   Those methods *cannot* be stubbed/verified.
   Mocking methods declared on non-public parent classes is not supported.
2. inside when() you don't call method on mock but on some other object.

我能知道为什么吗？

我的依赖：

<dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-core</artifactId>
            <version>2.0.4</version>
        </dependency>
        <dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-module-junit4</artifactId>
            <version>2.0.4</version>
            <scope>test</scope>
        </dependency>
    <dependency>
  <groupId>org.powermock</groupId>
  <artifactId>powermock-api-mockito2</artifactId>
  <version>2.0.4</version>
</dependency>