java在编译JUnit测试时找不到符号错误

Question

我一直在从《春天在行动》一书中学习春天。我打了一个例子来测试beans是否正在创建
以下是java文件
CDPlayerTest。爪哇

package soundsystem;

import static org.junit.Assert.*;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = CDPlayerConfig.class)
public class CDPlayerTest {
    @Autowired
    private CompactDisc cd;

    @Test
    public void cdShoulNotBeNull() {
        assertNotNull(cd);
    }
}

CDPlayerConfig。java

package soundsystem;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan
public class CDPlayerConfig {

}

sgtpepers。爪哇

package soundsystem;

import org.springframework.stereotype.Component;

@Component
public class SgtPeppers implements CompactDisc {

    private String title = "Sgt. Pepper's Lonely Hearts Club Road";
    private String artist = "The Beatles";

    @Override
    public void play() {
        // TODO Auto-generated method stub
        System.out.println("Playing " + title + " By " + artist);

    }

}

压缩光盘。爪哇

package soundsystem;

public interface CompactDisc {
    void play();
}

运行javac CDPlayerTest.java时，将打印以下错误

CDPlayerTest.java:15: error: cannot find symbol
    private CompactDisc cd;
            ^
  symbol:   class CompactDisc
  location: class CDPlayerTest
CDPlayerTest.java:12: error: cannot find symbol
@ContextConfiguration(classes = CDPlayerConfig.class)
                                ^
  symbol: class CDPlayerConfig
2 errors