当前位置：首页 > Java

java如何放到缓存

2026-03-22 04:49:52Java

使用Java实现缓存的几种方法

在Java中实现缓存可以通过多种方式完成，以下是一些常见的实现方法：

基于HashMap实现简单缓存

创建一个简单的缓存可以使用HashMap，但需要注意线程安全问题：

import java.util.HashMap;
import java.util.Map;

public class SimpleCache<K, V> {
    private final Map<K, V> cache = new HashMap<>();

    public synchronized void put(K key, V value) {
        cache.put(key, value);
    }

    public synchronized V get(K key) {
        return cache.get(key);
    }

    public synchronized void remove(K key) {
        cache.remove(key);
    }
}

使用Guava Cache

Google的Guava库提供了强大的缓存功能：

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

public class GuavaCacheExample {
    private static final Cache<String, String> cache = CacheBuilder.newBuilder()
        .maximumSize(100) // 最大缓存条目数
        .build();

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

    public static String get(String key) {
        return cache.getIfPresent(key);
    }
}

使用Caffeine Cache

java如何放到缓存

Caffeine是Guava Cache的现代替代品，性能更好：

import com.github.benmanes.caffeine.cache.Cache;
import com.github.benmanes.caffeine.cache.Caffeine;

public class CaffeineCacheExample {
    private static final Cache<String, String> cache = Caffeine.newBuilder()
        .maximumSize(100)
        .build();

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

    public static String get(String key) {
        return cache.getIfPresent(key);
    }
}

使用Ehcache

Ehcache是一个成熟的Java缓存框架：

java如何放到缓存

import org.ehcache.Cache;
import org.ehcache.CacheManager;
import org.ehcache.config.builders.CacheConfigurationBuilder;
import org.ehcache.config.builders.CacheManagerBuilder;
import org.ehcache.config.builders.ResourcePoolsBuilder;

public class EhcacheExample {
    private static CacheManager cacheManager;
    private static Cache<String, String> cache;

    static {
        cacheManager = CacheManagerBuilder.newCacheManagerBuilder().build();
        cacheManager.init();

        cache = cacheManager.createCache("myCache",
            CacheConfigurationBuilder.newCacheConfigurationBuilder(
                String.class, String.class,
                ResourcePoolsBuilder.heap(100)
            )
        );
    }

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

    public static String get(String key) {
        return cache.get(key);
    }
}

使用Spring Cache抽象

Spring框架提供了缓存抽象层：

import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

@Service
public class BookService {
    @Cacheable("books")
    public Book getBookByIsbn(String isbn) {
        // 模拟耗时操作
        simulateSlowService();
        return new Book(isbn, "Some book");
    }

    private void simulateSlowService() {
        try {
            Thread.sleep(3000L);
        } catch (InterruptedException e) {
            throw new IllegalStateException(e);
        }
    }
}

使用Redis作为分布式缓存

对于分布式系统，Redis是常用的缓存解决方案：

import redis.clients.jedis.Jedis;

public class RedisCacheExample {
    private static final String REDIS_HOST = "localhost";
    private static final int REDIS_PORT = 6379;

    public static void set(String key, String value) {
        try (Jedis jedis = new Jedis(REDIS_HOST, REDIS_PORT)) {
            jedis.set(key, value);
        }
    }

    public static String get(String key) {
        try (Jedis jedis = new Jedis(REDIS_HOST, REDIS_PORT)) {
            return jedis.get(key);
        }
    }
}