策略模式-实践

策略模式

1. 定义一个策略接口

public interface IFileStrategy {

    // 获取文件类型
    FileTypeResolveEnum gainFileType();

    // 文件处理的方法
    void resolve(Object objectParam);

}


enum FileTypeResolveEnum {
    FILE_A_RESOLVE,
    FILE_B_RESOLVE;
}

策略A的实现方式

/**
 * 文件A的处理策略
 */
@Component
@Slf4j
public class AFileResolve implements IFileStrategy {

    @Override
    public FileTypeResolveEnum gainFileType() {
        return FileTypeResolveEnum.FILE_A_RESOLVE;
    }

    @Override
    public void resolve(Object objectParam) {
        log.info("A类型解析文件的参数" + objectParam);
    }
}

策略B的实现

/**
 * 文件B的处理策略
 */
@Slf4j
@Component
public class BFileResolve implements IFileStrategy {

    @Override
    public FileTypeResolveEnum gainFileType() {
        return FileTypeResolveEnum.FILE_B_RESOLVE;
    }

    @Override
    public void resolve(Object objectParam) {
        log.info("B文件类型解析参数" + objectParam);
    }
}

策略的使用

@Component
public class StrategyService implements ApplicationContextAware {

    private Map<FileTypeResolveEnum, IFileStrategy> map = new ConcurrentHashMap<>();

    public void resolveFile(FileTypeResolveEnum fileTypeResolveEnum, Object objectParam) {
        IFileStrategy fileStrategy = map.get(fileTypeResolveEnum);
        if (fileStrategy != null) {
            fileStrategy.resolve(objectParam);
        }
    }


    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        Map<String, IFileStrategy> beansOfType = applicationContext.getBeansOfType(IFileStrategy.class);
        Collection<IFileStrategy> values = beansOfType.values();
        values.stream().forEach(fileStrategy -> map.put(fileStrategy.gainFileType(), fileStrategy));
    }
}