JAVA设计模式-策略模式应用实例

应用场景：资讯app对用户的有益反馈、首次评论、分享、版本更新等发放积分，积分系统分别设置有益反馈、首次评论、分享、版本更新的积分规则，根据不同的积分规则取出要送的积分。

基础策略接口

public interface BaseStrategy {

/**
* 根据规则计算积分
*
* @param param
* @return
*/
Long calculate(StrategyParam param);

/**
* 类型
*
* @return
*/
ISChannelType getFlag();
}

抽象类，实现通用计算积分方法，特殊的子类重写计算积分方法即可

public abstract class IntegralAbstractStrategy implements BaseStrategy{
@Resource
ISAccountDetailMapper iSAccountDetailMapper;
/**
* 简单获取 积分
* @param param
* @return
*/
@Override
public Long calculate(StrategyParam param) {
RuleData ruleData = param.getRule().get(RuleKeys.FEEDBACK);
if (ruleData!=null){
return Long.valueOf(StringUtil.isBlank(ruleData.getValue())?"0":ruleData.
4000
getValue());
}
return 0L;
}
}

有益分享实现

@Component("feedbackStrategy")
public class FeedbackStrategy extends IntegralAbstractStrategy {
@Override
public ISChannelType getFlag() {
return ISChannelType.FEEDBACK;
}
}

首次评论实现

@Component("firstCommentStrategy")
public class FirstCommentStrategy extends IntegralAbstractStrategy {
@Override
public Long calculate(StrategyParam param) {
String userId = param.getUserId();
Map<String, RuleData> rule = param.getRule();
if (rule.containsKey(RuleKeys.FIRST_COMMENT)) {
RuleData ruleData = rule.get(RuleKeys.FIRST_COMMENT);
String value = ruleData.getValue();
if (StringUtil.isNotBlank(value)) {
//首次评论防止重复，增加校验
ISAccountDetailExample example = new ISAccountDetailExample();
ISAccountDetailExample.Criteria criteria = example.createCriteria();
criteria.andUserIdEqualTo(userId);
criteria.andChannelEqualTo(ISChannelType.FIRST_COMMENT.getCode());
List<ISAccountDetail> isAccountDetails = iSAccountDetailMapper.selectByExample(example);
if (CollectionUtils.isEmpty(isAccountDetails)) {
Long amount = Long.valueOf(value);
return amount;
}
}
}
return 0L;
}

@Override
public ISChannelType getFlag() {
return ISChannelType.FIRST_COMMENT;
}
}

积分渠道枚举

public enum ISChannelType implements BaseEnum {

//新用户

NEW_REGISTER(0, "NEW_REGISTER", "新用户注册"),

FIRST_COMMENT(0, "FIRST_COMMENT", "首次评论"),

FIRST_SHARE(0, "FIRST_SHARE", "首次分享"),

//常规

DRAW(1, "DRAW", "抽奖"),

READ_RED(1, "READ_RED", "阅读红包"),

COMMENT(1, "COMMENT", "用户评论"),

SHARE(1, "SHARE", "文章分享"),

INVITE(1, "INVITE", "邀请好友"),

FEEDBACK(1, "FEEDBACK", "有益反馈"),

UPDATE_VERSION(1, "UPDATE_VERSION", "APP版本更新"),

JIFEN_CONVERT(1, "JIFEN_CONVERT", "积分兑换金额"),

JIFEN_CONVERT_DRAW(1, "JIFEN_CONVERT_DRAW", "积分兑换抽奖次数"),

JIFEN_VALID(1, "JIFEN_VALID", "积分有效期"),;

/**
* 类型，0为新用户专有，1为常规
*/
private int type;

private String code;

private String desc;

ISChannelType(int type, String code, String desc) {
this.type = type;
this.code = code;
this.desc = desc;
}

/**
* 获取所有渠道code
*
* @return
*/
public static List<String> getCodes() {
List<String> codes = Lists.newArrayList();
ISChannelType[] values = ISChannelType.values();
for (ISChannelType value : values) {
codes.add(value.getCode());
}
return codes;
}

/**
* 获取枚举代码
*/
@Override
public String getCode() {
return code;
}

/**
* 获取枚举描述
*/
@Override
public String getDesc() {
return desc;
}

/**
* Getter method for property <tt>type</tt>
*
* @re
c9af
turn property value of type
*/
public int getType() {
return type;
}
}

策略工厂

@Component
public class StrategyFactory extends ApplicationObjectSupport {
private transient Logger log = LoggerFactory.getLogger(getClass());

private static Map<String, BaseStrategy> strategyMap = new HashMap<>();

@PostConstruct
private void init() {
Map<String, BaseStrategy> beansOfType = getApplicationContext().getBeansOfType(BaseStrategy.class);
beansOfType.values().forEach(it -> strategyMap.put(it.getFlag().getCode(), it));
log.info("Registered strategy size: {}", strategyMap.size());
}

public BaseStrategy creator(String type) {
return strategyMap.get(type);
}
}

调用：

@Resource
private StrategyFactory strategyFactory;

Long amount = strategyFactory.creator(req.getChannel()).calculate(param);