首先在pom.xml中导入guava依赖：

<dependency>
  <groupId>com.google.guava</groupId>
  <artifactId>guava</artifactId>
  <version>28.2-jre</version>
</dependency>

然后创建类

package com.itranswarp.learnjava.templatemethod;

import com.google.common.cache.*;

public class GuavaCacheSetting extends AbstractSetting {
	private Cache<String, String> cache = CacheBuilder.newBuilder().build();

	@Override
	protected String lookupCache(String key) {
		return cache.getIfPresent(key);
	}

	@Override
	protected void putIntoCache(String key, String value) {
		cache.put(key, value);
	}

}