1.对象池策略
2.对象空闲时间超时清除策略
- 实现ObjectFactory接口
/**
* create new object
*/
public interface ObjectFactory<T> {
/**
* crete new object
* @return T
*/
public abstract T createNew();
}根据自己的需要的对象去实现新建对象方法
例子：
public class JDBCConnectionFactory implements ObjectFactory<Connection> {
private String connectionURL;
private String userName;
private String password;
public JDBCConnectionFactory(String driver, String connectionURL, String userName, String password) {
super();
try {
Class.forName(driver);
}catch (ClassNotFoundException e) {
throw new IllegalArgumentException("Unable to find driver in classpath ", e);
}
this.connectionURL = connectionURL;
this.userName = userName;
this.password = password;
}
@Override
public Connection createNew() {
try {
return DriverManager.getConnection(connectionURL, userName, password);
}catch (SQLException e) {
throw new IllegalArgumentException("Uable to create new connection", e);
}
}
}- 实现Validator接口
public interface Validator<T> {
/**
* whether object is valid
* @param t
* @return
*/
public boolean isValid(T t);
/**
* clear object
* @param t
*/
public void invalidate(Base<T> t);
}实现判断对象是否合法，以及将对象清空
例子:
public final class JDBCConnectionValidator implements Validator<Connection> {
@Override
public boolean isValid(Connection connection) {
if(connection==null) return false;
try {
return !connection.isClosed();
}catch (SQLException e) {
return false;
}
}
@Override
public void invalidate(Base<Connection> t) {
try {
t.getT().close();
}catch (SQLException e) {
}
}
}- 新建一个Pool pool,得到一个对象池
public final class PoolFactory<T> {
private PoolFactory(){}
/**
*
* @param coreSize
* @param maxSize
* @param keepAliveTime
* @param unit
* @param validator
* @param objectFactory
* @param <T>
* @return
*/
public static <T> Pool<T> newBoundedBlockingPool(int coreSize, int maxSize, long keepAliveTime, TimeUnit unit, Validator<T> validator, ObjectFactory<T> objectFactory){
return new BoundedBlockingPool<T>(coreSize, maxSize, keepAliveTime, unit, validator, objectFactory);
}
}1.在pom中引入包
<groupId>com.wtk</groupId>
<artifactId>objectPool</artifactId>
<version>1.0-SNAPSHOT</version>2.实现ObjectFactory和Validator两个接口
public class StringBufferFactory implements ObjectFactory<StringBuffer> {
@Override
public StringBuffer createNew() {
return new StringBuffer();
}
} public class StringBufferValidator implements Validator<StringBuffer> {
@Override
public boolean isValid(StringBuffer stringBuffer) {
if(stringBuffer==null) return false;
return true;
}
@Override
public void invalidate(Base<StringBuffer> t) {
t = null;
}
}3.创建一个对象池并测试
例子: 创建一个StrinigBuffer对象池
public static void main(String[] args) {
Pool<StringBuffer> pool = PoolFactory.newBoundedBlockingPool(5, 10, 1000, TimeUnit.MILLISECONDS, new StringBufferValidator(), new StringBufferFactory());
try {
StringBuffer stringBuffer1 = pool.get(1000, TimeUnit.MILLISECONDS);
StringBuffer stringBuffer2 = pool.get(1000, TimeUnit.MILLISECONDS);
StringBuffer stringBuffer3 = pool.get(1000, TimeUnit.MILLISECONDS);
StringBuffer stringBuffer4 = pool.get(1000, TimeUnit.MILLISECONDS);
StringBuffer stringBuffer5 = pool.get(1000, TimeUnit.MILLISECONDS);
StringBuffer stringBuffer6 = pool.get(1000, TimeUnit.MILLISECONDS);
stringBuffer6.append("hello");
pool.release(stringBuffer4);
pool.release(stringBuffer5);
pool.release(stringBuffer6);
long cur = System.currentTimeMillis();
while(true) {
// long cur = System.currentTimeMillis();
if (System.currentTimeMillis() - cur > 10) {
break;
}
}
StringBuffer stringBuffer7 = pool.get(1000, TimeUnit.MILLISECONDS);
System.out.println("stringBuffer7"+stringBuffer7.toString());
StringBuffer stringBuffer8 = pool.get(1000, TimeUnit.MILLISECONDS);
System.out.println("stringBuffer8"+stringBuffer8.toString());
StringBuffer stringBuffer9 = pool.get(1000, TimeUnit.MILLISECONDS);
System.out.println("stringBuffer9"+stringBuffer9.toString());
StringBuffer stringBuffer10 = pool.get(1000, TimeUnit.MILLISECONDS);
System.out.println("stringBuffer10"+stringBuffer10.toString());
StringBuffer stringBuffer11 = pool.get(1000, TimeUnit.MILLISECONDS);
System.out.println("stringBuffer11"+stringBuffer11.toString());
System.out.println("----------------finish!");
cur = System.currentTimeMillis();
while(true) {
// long cur = System.currentTimeMillis();
if (System.currentTimeMillis() - cur > 2000) {
break;
}
}
System.out.println(BoundedBlockingPool.count);
} catch (InterruptedException e) {
e.printStackTrace();
}
}