详解Java中对象池的介绍与使用

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

import com.scl.online.service.model.SxInferContext;
import org.apache.commons.pool2.PooledObject;
import org.apache.commons.pool2.PooledObjectFactory;
import org.apache.commons.pool2.impl.DefaultPooledObject;

 
public class InferContextPooledObjectFactory implements PooledObjectFactory<SxInferContext> {

  @Override
  public PooledObject<SxInferContext> makeObject() {
    SxInferContext inferContext = new SxInferContext();
    return new DefaultPooledObject<>(inferContext);
  }

  @Override
  public void destroyObject(PooledObject<SxInferContext> pooledObject) {

  }

  @Override
  public boolean validateObject(PooledObject<SxInferContext> pooledObject) {
    return true;
  }

  @Override
  public void activateObject(PooledObject<SxInferContext> pooledObject) {
    pooledObject.getObject().initObject();
  }

  @Override
  public void passivateObject(PooledObject<SxInferContext> pooledObject) {
    // 当ObjectPool实例返还池中的时候调用
    pooledObject.getObject().initObject();
  }
}

public GenericObjectPool<SxInferContext> contextPools;

@PostConstruct
  public void init() {
    if (sxInferConfig.isObjectPoolUsable()) {
      InferContextPooledObjectFactory factory = new InferContextPooledObjectFactory();
      //设置对象池的相关参数
      GenericObjectPoolConfig poolConfig = initConfig();
      //新建一个对象池,传入对象工厂和配置
      contextPools = new GenericObjectPool<>(factory, poolConfig);
    }
  }


   
  public GenericObjectPoolConfig initConfig() {
    GenericObjectPoolConfig cfg = new GenericObjectPoolConfig();
    cfg.setJmxNamePrefix("objectPool");
    //  对象总数
    cfg.setMaxTotal(sxInferConfig.getPoolMaxTotal());
    // 最大空闲对象数
    cfg.setMaxIdle(sxInferConfig.getPoolMaxIdle());
    // 最小空闲对象数
    cfg.setMinIdle(sxInferConfig.getPoolMinIdle());
    // 借对象阻塞最大等待时间
    // 获取资源的等待时间。blockWhenExhausted 为 true 时有效。-1 代表无时间限制，一直阻塞直到有可用的资源
    cfg.setMaxWaitMillis(sxInferConfig.getPoolMaxWait());
    // 最小驱逐空闲时间
    cfg.setMinEvictableIdleTimeMillis(sxInferConfig.getPoolMinEvictableIdleTimeMillis());
    // 每次驱逐数量  资源回收线程执行一次回收操作，回收资源的数量。默认 3
    cfg.setNumTestsPerEvictionRun(sxInferConfig.getPoolNumTestsPerEvictionRun());
    // 回收资源线程的执行周期，默认 -1 表示不启用回收资源线程
    cfg.setTimeBetweenEvictionRunsMillis(sxInferConfig.getPoolTimeBetweenEvictionRunsMillis());
    // 资源耗尽时，是否阻塞等待获取资源，默认 true
    cfg.setBlockWhenExhausted(sxInferConfig.isPoolBlockWhenExhausted());
    return cfg;
  }