使用一个内存的List来保存对象的Json字符串，从而实现一个内存的dummy DAO对象，可以用来作为单元测试的测试替身。
<repositories>
<repository>
<id>jitpack.io</id>
<url>https://jitpack.io</url>
</repository>
</repositories>
<dependency>
<groupId>com.github.bobdeng</groupId>
<artifactId>dummydao</artifactId>
<version>1.0</version>
</dependency>
初始化一个DAO，用DummyDAO构造一个测试替身DeviceRepositoryImpl
DummyDao<Device, Integer> dummyDao = new DummyDao<>(Device.class, "id", new AutoIntegerIdGenerator());
deviceService = new DeviceServiceImpl(new DeviceRepositoryImpl(dummyDao));
DeviceRepositoryImpl.java
public class DeviceRepositoryImpl implements DeviceRepository {
private final DummyDao<Device, Integer> dummyDao;
public DeviceRepositoryImpl(DummyDao<Device, Integer> dummyDao) {
this.dummyDao = dummyDao;
}
@Override
public Device save(Device entity) {
return dummyDao.save(entity);
}
@Override
public Optional<Device> findByMac(String mac) {
return dummyDao.all().stream()
.filter(device -> device.isSame(mac))
.findFirst();
}
}