自定义连接池

1. pom.xml

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
    <version>2.11.1</version>
</dependency>

2. factory

package cn.idea360.i18n.pool;

import org.apache.commons.pool2.BasePooledObjectFactory;
import org.apache.commons.pool2.PooledObject;
import org.apache.commons.pool2.impl.DefaultPooledObject;

import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author cuishiying
 * @date 2024-02-29
 */
public class StringPoolFactory extends BasePooledObjectFactory<String> {

    private final AtomicInteger sum = new AtomicInteger(0);

    public StringPoolFactory() {
        super();
    }

    @Override
    public String create() throws Exception {
        return "str-val-" + sum.incrementAndGet();
    }

    @Override
    public PooledObject<String> wrap(String s) {
        System.out.println("包装: " + s);
        return new DefaultPooledObject<>(s);
    }

    @Override
    public void destroyObject(PooledObject<String> p) throws Exception {
        System.out.println("销毁: " + p.getObject());
        super.destroyObject(p);
    }

    @Override
    public boolean validateObject(PooledObject<String> p) {
        System.out.println("校验: " + p.getObject());
        return super.validateObject(p);
    }

    @Override
    public void activateObject(PooledObject<String> p) throws Exception {
        System.out.println("获取: " + p.getObject());
        super.activateObject(p);
    }

    @Override
    public void passivateObject(PooledObject<String> p) throws Exception {
        System.out.println("归还: " + p.getObject());
        super.passivateObject(p);
    }

}

3. pool

package cn.idea360.i18n.pool;

import org.apache.commons.pool2.PooledObjectFactory;
import org.apache.commons.pool2.impl.AbandonedConfig;
import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;

/**
 * @author cuishiying
 * @date 2024-02-29
 */
public class StringPool extends GenericObjectPool<String> {

    public StringPool(PooledObjectFactory<String> factory) {
        super(factory);
    }

    public StringPool(PooledObjectFactory<String> factory, GenericObjectPoolConfig<String> config) {
        super(factory, config);
    }

    public StringPool(PooledObjectFactory<String> factory, GenericObjectPoolConfig<String> config, AbandonedConfig abandonedConfig) {
        super(factory, config, abandonedConfig);
    }
}

4. test

package cn.idea360.i18n.pool;

import org.apache.commons.pool2.impl.GenericObjectPoolConfig;

import java.time.Duration;
import java.util.concurrent.CountDownLatch;

/**
 * @author cuishiying
 * @date 2024-02-29
 */
public class PoolTest {

    public static void main(String[] args) throws Exception {
        StringPoolFactory factory = new StringPoolFactory();
        GenericObjectPoolConfig<String> config = new GenericObjectPoolConfig<>();
        config.setMaxTotal(3);
        config.setMinIdle(1);
        config.setMaxWait(Duration.ofMillis(1000));
        StringPool pool = new StringPool(factory, config);

        int count = 10;
        CountDownLatch c = new CountDownLatch(count);
        for (int i = 0; i < count; i++) {
            new Thread(() -> {
                test(pool);
                c.countDown();
            }).start();

        }
        c.await();
        System.out.println("活跃数: " + pool.getNumActive());
        System.out.println("空闲数: " + pool.getNumIdle());
    }

    private static void test(StringPool pool) {
        String s = null;
        try {
            s = pool.borrowObject();
            System.out.println("输出: " + s);
        } catch (Exception e) {
            e.printStackTrace();
            if (null != s) {
                pool.returnObject(s);
            }
        } finally {
            if (null != s) {
                pool.returnObject(s);
            }
        }
    }
}