PowerMockとmockitoを同時に使う

pom.xml（Mavenを使用している場合）に必要な依存関係を追加

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-core</artifactId>
    <version>4.x.x</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-module-junit4</artifactId>
    <version>2.x.x</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-api-mockito2</artifactId>
    <version>2.x.x</version>
    <scope>test</scope>
</dependency>

テストクラス

import static org.mockito.Mockito.*;
import static org.powermock.api.mockito.PowerMockito.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.junit.MockitoJUnitRunner;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.powermock.modules.junit4.PowerMockRunnerDelegate;

@RunWith(PowerMockRunner.class)
@PowerMockRunnerDelegate(MockitoJUnitRunner.class)
@PrepareForTest({ClassWithStaticMethod.class})
public class ExampleTest {

    @Mock
    private DependencyClass dependency;

    @Test
    public void testStaticMethod() {
        // 静的メソッドのモック設定
        mockStatic(ClassWithStaticMethod.class);
        when(ClassWithStaticMethod.staticMethod()).thenReturn("mocked value");

        // 通常のモック設定
        when(dependency.someMethod()).thenReturn("some value");

        // テストの実行
        String result = new ClassUnderTest(dependency).methodUnderTest();

        // アサーション
        assertEquals("expected value", result);
    }
}

参考