Guava工具

1. 缓存
2. 类型转化
3. 字符分割

        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>31.1-jre</version>
        </dependency>
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package com.steven.springboot.redis.utils;

import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import org.springframework.boot.autoconfigure.mail.MailProperties;

import javax.validation.constraints.Max;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

public class GuavaUtil {
    private static Cache<String, Object> dataMap = CacheBuilder.newBuilder()
            //设置cache的初始大小为10，要合理设置该值
            .initialCapacity(100)
            .maximumSize(1000)
            //设置并发数为5，即同一时间最多只能有5个线程往cache执行写入操作
            .concurrencyLevel(5)
            //设置cache中的数据在写入之后的存活时间
            .expireAfterWrite(3, TimeUnit.SECONDS)
            .build();

    public static void put(String key, Object value) {
        dataMap.put(key, value);
    }

    /**
     * 如果key不存在，返回null
     */
    public static Object get(String key) {
        return dataMap.getIfPresent(key);
    }

    /**
     * 移除key
     */
    public static void remove(String key) {
        dataMap.invalidate(key);
    }

    /**
     * 字符串分割
     *
     * @param list 集合
     * @return 字符串
     */
    public static String spliter(List<Object> list) {
        return Joiner.on(",").join(list);
    }

    public static String mapToString(Map<String, Object> map) {
        return Joiner.on(",").withKeyValueSeparator("=").join(map);
    }

    /**
     * 将String转化为list
     * @param str 带转化字符串
     * @return 转化成的list
     */
    public static List<String> stringToList(String str){
        return Splitter.on(",").splitToList(str);
    }

    public static void main(String[] args) throws InterruptedException {
        /*GuavaCacheUtil.put("name","jack");*/
        /*//jack*/
        /*System.out.println(GuavaCacheUtil.get("name"));*/
        /*GuavaCacheUtil.remove("name");*/
        /*//null*/
        /*System.out.println(GuavaCacheUtil.get("name"));*/
      /*  String split = spliter(Arrays.asList(1, 2, 3, 4, 5));
        System.out.println(split);*/
        /*HashMap<String, Object> result = new HashMap<>();
        result.put("1", "张三");
        result.put("2", "李四");
        String string = mapToString(result);
        System.out.println(string);*/
        List<String> strings = stringToList("1,2,3,4");
        System.out.println(strings);
    }
}
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public static void main(String[] args) throws InterruptedException {
        ThreadFactory factory = new DefaultThreadFactory("task", 4);
        ExecutorService threadPool = new ThreadPoolExecutor(3, 6, 20, TimeUnit.MINUTES, new ArrayBlockingQueue<>(30), factory, new ThreadPoolExecutor.DiscardPolicy());
        ListeningExecutorService service = MoreExecutors.listeningDecorator(threadPool);
        ListenableFuture<String> future = service.submit(() -> {
            System.out.println("任务在执行！！！");
            return "task";
        });

        future.addListener(()->{
            try {
                future.get();
            } catch (InterruptedException | ExecutionException e) {
                e.printStackTrace();
            }
        }, service);

        Futures.addCallback(future, new FutureCallback<String>(){
            @Override
            public void onSuccess(String s) {
                System.out.println("callback result:"+s);
            }

            @Override
            public void onFailure(Throwable throwable) {
                System.out.println(throwable.getMessage());
            }
        },service);

    }
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