多个Bean自动注入成Map @Autowired @Service 策略模式

需求

将多个策略的具体实现自动注入到Map中

准备

一个接口，有doSomething()方法

多个具体实现策略，实现doSomething()方法

一个Controller，用于测试自动注入

源代码

public interface DemoInterface
{
    void doSomething();
}

@Service
public class DemoService implements DemoInterface
{
    public void doSomething()
    {
        System.out.println("call me");
    }
}

@Service("my-own-name-2")
public class DemoService2 implements DemoInterface
{
    public void doSomething()
    {
        System.out.println("2 call me");
    }
}

@Component
public class DemoService3 implements DemoInterface
{
    public void doSomething()
    {
        System.out.println("3 call me");
    }
}

@RestController
public class DemoController
{
    @Autowired
    private Map<String,DemoInterface> demoServiceMap;
​
    @GetMapping("/test")
    public String test(){
        for(Map.Entry<String, DemoInterface> entry : demoServiceMap.entrySet()){
            System.out.println(entry.getKey());
            System.out.println(entry.getValue());
        }
        return "succ";
    }
}

测试结果

demoService
com.example.testtwo.DemoService@75d2647f
my-own-name-2
com.example.testtwo.DemoService2@1a5055cf
demoService3
com.example.testtwo.DemoService3@fe6916c

策略模式实现

需求

文件上传功能，可以使用oss和minio两种方式

准备

策略接口，包含uploadFile()方法

public interface UploadStrategy {
    String uploadFile(MultipartFile file, String path);
    String uploadFile(String fileName, InputStream inputStream, String path);
}

抽象实现，抽象出一些公共逻辑，留出不同策略区别的方法进一步具体实现（非必要）

public abstract class AbstractUploadStrategyImpl implements UploadStrategy{
    @Override
    public String uploadFile(MultipartFile file, String path) {
        try {
            String md5 = FileUtil.getMd5(file.getInputStream());
            String extName = FileUtil.getExtName(file.getOriginalFilename());
            String fileName = md5 + extName;
            if (!exists(path + fileName)) {
                upload(path, fileName, file.getInputStream());
            }
            return getFileAccessUrl(path + fileName);
        } catch (Exception e) {
            e.printStackTrace();
            throw new BizException("文件上传失败");
        }
    }
    @Override
    public String uploadFile(String fileName, InputStream inputStream, String path) {
        try {
            upload(path, fileName, inputStream); // 具体上传策略
            return getFileAccessUrl(path + fileName); // 具体文件路径
        } catch (Exception e) {
            e.printStackTrace();
            throw new BizException("文件上传失败");
        }
    }
    public abstract Boolean exists(String filePath);
​
    public abstract void upload(String path, String fileName, InputStream inputStream) throws IOException;
​
    public abstract String getFileAccessUrl(String filePath);
}

具体实现

Oss

@Service("ossUploadStrategyImpl")
public class OssUploadStrategyImpl extends AbstractUploadStrategyImpl {

    @Autowired
    private OssConfigProperties ossConfigProperties;

    @Override
    public Boolean exists(String filePath) {
        return getOssClient().doesObjectExist(ossConfigProperties.getBucketName(), filePath);
    }

    @Override
    public void upload(String path, String fileName, InputStream inputStream) {
        getOssClient().putObject(ossConfigProperties.getBucketName(), path + fileName, inputStream);
    }

    @Override
    public String getFileAccessUrl(String filePath) {
        return ossConfigProperties.getUrl() + filePath;
    }

    private OSS getOssClient() {
        return new OSSClientBuilder().build(ossConfigProperties.getEndpoint(), ossConfigProperties.getAccessKeyId(), ossConfigProperties.getAccessKeySecret());
    }

}

Minio

@Service("minioUploadStrategyImpl")
public class MinioUploadStrategyImpl extends AbstractUploadStrategyImpl {

    @Autowired
    private MinioProperties minioProperties;

    @Override
    public Boolean exists(String filePath) {
        boolean exist = true;
        try {
            getMinioClient()
                    .statObject(StatObjectArgs.builder().bucket(minioProperties.getBucketName()).object(filePath).build());
        } catch (Exception e) {
            exist = false;
        }
        return exist;
    }

    @SneakyThrows
    @Override
    public void upload(String path, String fileName, InputStream inputStream) {
        getMinioClient().putObject(
                PutObjectArgs.builder().bucket(minioProperties.getBucketName()).object(path + fileName).stream(
                                inputStream, inputStream.available(), -1)
                        .build());
    }

    @Override
    public String getFileAccessUrl(String filePath) {
        return minioProperties.getUrl() + filePath;
    }

    private MinioClient getMinioClient() {
        return MinioClient.builder()
                .endpoint(minioProperties.getEndpoint())
                .credentials(minioProperties.getAccessKey(), minioProperties.getSecretKey())
                .build();
    }

}

枚举

// 把复杂的方法名与实际技术名词对应
public enum UploadModeEnum {

    OSS("oss", "ossUploadStrategyImpl"),

    MINIO("minio", "minioUploadStrategyImpl");

    private final String mode;

    private final String strategy;

    public static String getStrategy(String mode) {
        for (UploadModeEnum value : UploadModeEnum.values()) {
            if (value.getMode().equals(mode)) {
                return value.getStrategy();
            }
        }
        return null;
    }

}

使用

@Autowired
private Map<String, UploadStrategy> uploadStrategyMap; // 自动注入UploadStrategy接口的实现类

uploadStrategyMap.get(getStrategy("oss")).uploadFile(file, path); // 先根据技术名词获得策略具体实现方法名，再从map中拿到对象，调用对象方法

参考

源码：https://github.com/linhaojun857/aurora

原理：https://www.cnblogs.com/lifullmoon/p/14453011.html