java 用枚举替换多if-else(转载)

1、定义抽象类

package com.polaris.design;

/**

• @author ：shi
• @date ：Created in 2020/8/18 20:15
• @description：
• @modified By：
  */
  public abstract class GeneralChannelRule {
  public abstract void process();
  }

2、实现抽象类方法
package com.polaris.design;

/**

• @author ：shi

• @date ：Created in 2020/8/18 20:18

• @description：

• @modified By：
  */
  public class JDChannelRule extends GeneralChannelRule {

  @Override
  public void process() {
  System.out.println("我们大京东！");
  }
  }

3、枚举
package com.polaris.design;

/**

• @author ：shi

• @date ：Created in 2020/8/18 20:18

• @description：

• @modified By：
  */
  public enum ChannelRuleEnum {

  /**

  • 京东
    */
    JD("JD", new JDChannelRule()),

  /**

  • 头条
    */
    TOUTIAO("TOUTIAO", new TouTiaoChannelRule()),

  /**

  • 腾讯
    */
    TENCENT("TENCENT", new TencentChannelRule());

  public String name;

  public GeneralChannelRule channel;

  ChannelRuleEnum(String name, GeneralChannelRule channel) {
  this.name = name;
  this.channel = channel;
  }

  //匹配
  public static ChannelRuleEnum match(String name) {
  ChannelRuleEnum[] values = ChannelRuleEnum.values();
  for (ChannelRuleEnum value : values) {
  if (value.name.equals(name)) {
  return value;
  }
  }
  return null;
  }

  public String getName() {
  return name;
  }

  public GeneralChannelRule getChannel() {
  return channel;
  }
  }

4、测试
package com.polaris.design;

/**

• @author ：shi

• @date ：Created in 2020/8/18 20:27

• @description：

• @modified By：
  */
  public class Test1 {

  public static void main(String[] args) {
  String sign = "JD";
  ChannelRuleEnum channelRule = ChannelRuleEnum.match(sign);
  GeneralChannelRule rule = channelRule.channel;
  rule.process();
  }
  }