举例讲解Java设计模式中的对象池模式编程

import java.util.Stack;  @SuppressWarnings("unchecked") public class ObjectPool {    public ObjectPool() {   }    private PoolParam poolParam;    public void setPoolParam(PoolParam poolParam) {     this.poolParam = poolParam;   }    // 当前总对象个数   private int currentNum = 0;    private Class clazz;    public void setClazz(Class clazz) {     this.clazz = clazz;   }    // 栈，用来存放对象，模拟一个池   private Stack stack;    public Stack getStack() {     return stack;   }    public void setStack(Stack stack) {     this.stack = stack;   }    // .................................................................   // 等待超时的记数变量   private int timeWait = 0;    // .................................................................    // 创建对象池   public void initalPool(PoolParam poolParam, Class clazz) {      this.setPoolParam(poolParam);     this.setClazz(clazz);      stack = new Stack();      stack.clear();      // System.out.println("obj..pool is initial...");     // 生成配置最小对象数，并压入栈中     try {        for (int i = 0; i < poolParam.getMinObjectCount(); i++) {          // 根据poolParam初始化对象池         stack.push(clazz.newInstance());       }      } catch (InstantiationException e) {       e.printStackTrace();     } catch (IllegalAccessException e) {       e.printStackTrace();     }    }    // 创建单个对象   private Object createObj(Class clazz) {      Object obj = null;     try {        obj = clazz.newInstance();        // System.out.println("a new one...");     } catch (InstantiationException e) {       e.printStackTrace();     } catch (IllegalAccessException e) {       e.printStackTrace();     }      return obj;   }    // 对象池提供的get方法   public Object getInstance(){      // System.out.println(stack.size());      Object object = null;      if (stack.size() == 0) {        // 如果当前栈的长度为0，并且总的对象数没有超过定义最大数       if ((currentNum + poolParam.getMinObjectCount()) < poolParam           .getMaxObjectCount()) {          // 新创建一个对象         object = this.createObj(clazz);         // 对象数+1         currentNum++;        } else {          synchronized (this) {            try {             waitme(this);           } catch (Exception e) {             e.printStackTrace();           }            // 获得通知后检测栈中是为空，并给出刚刚释放的资源           if (!stack.empty()) {             object = stack.pop();           }         }       }      } else if (stack.size() > 0) {        object = stack.pop();        // System.out.println(stack.size());     }      return object;   }    // 返回对象的方法   public void returnObj(Object obj) {      if (clazz.isInstance(obj)) {        stack.push(obj);        synchronized (this) {          notify();       }     } else {       System.out.println("this object can not push to stack!");     }    }    // 等待递归算法   private void waitme(ObjectPool pool) {      // 等待2s的技术控制     if (timeWait >= 2000) {       System.out.println("jump up this step..");        timeWait = 0;       return;      } else {        try {          pool.wait(500);          // 等待计数累加。。         timeWait +=1000;          System.out.println("waiting time to free obj..");          if (stack.empty()) {           System.out.println("agian....");           waitme(pool);         }        } catch (InterruptedException e) {         e.printStackTrace();       }     }   }  } 

@SuppressWarnings("unchecked") public class ObjectPoolManage {    private ObjectPoolManage() {   }    private static ObjectPool pool;        // 实现一个单例的获取方法....默认   public static synchronized ObjectPool getCacheObject(Class clazz) {      if (null != pool) {       return pool;     } else {        createObjectPool(null, clazz);       return pool;     }    }    // 实现一个单例的获取方法...自定义    public static synchronized ObjectPool getCacheObject(PoolParam p, Class clazz) {     if (null != pool) {       return pool;     } else {        createObjectPool(p, clazz);       return pool;     }    }    private static ObjectPool createObjectPool(PoolParam p, Class clazz) {      pool = new ObjectPool();      if (null == p) {       pool.initalPool(new PoolParam(5,10), clazz);     } else {       pool.initalPool(p, clazz);     }      return pool;   }      private static Class getclazz(){          Class clazz=null;          try {       clazz= Class.forName(ppp.getPropertyByName("objectPath"));     } catch (ClassNotFoundException e) {       e.printStackTrace();     }          return clazz;   } }