这是我的演示:
PoolableObjectFactoryImpl.java
public class PoolableObjectFactoryImpl implements PoolableObjectFactory<Result> {
private static Logger logger = Logger.getLogger("BackgroundLog");
@Override
public void activateObject(Result obj) throws Exception {
logger.info("==activate result.==");
obj.setResult(-999);
}
@Override
public void destroyObject(Result obj) throws Exception {
logger.info("==destroy result.==");
obj = null;
}
@Override
public Result makeObject() throws Exception {
logger.info("==make result.==");
Result result = new Result();
return result;
}
@Override
public void passivateObject(Result obj) throws Exception {
logger.info("==passivate result.==");
obj.setResult(-999);
}
@Override
public boolean validateObject(Result obj) {
/*if(obj.getResult() == -999){
logger.info("==validate result true.==");
return true;
}else{
logger.info("==validate result false.==");
return false;
}*/
logger.info("==validate result true.==");
return true;
}
}
线程池.java
public class ThreadPool extends GenericObjectPool {
private static Logger logger = Logger.getLogger("BackgroundLog");
private static ThreadPool pool = null;
private Map<String, String> map = getConfig();
private ThreadPool() {
this.setFactory(new PoolableObjectFactoryImpl());
this.setMaxActive(Integer.parseInt(map.get("maxActive")));
this.setWhenExhaustedAction(Byte.valueOf(map.get("whenExhaustedAction")));
this.setMaxWait(Long.parseLong(map.get("maxWait")));
this.setMaxIdle(Integer.parseInt(map.get("maxIdle")));
this.setTestOnBorrow(Boolean.valueOf(map.get("testOnBorrow")));
this.setTestOnReturn(Boolean.valueOf(map.get("testOnReturn")));
this.setTimeBetweenEvictionRunsMillis(Long.parseLong(map.get("timeBetweenEvictionRunsMillis")));
this.setNumTestsPerEvictionRun(Integer.parseInt(map.get("numTestsPerEvictionRun")));
this.setMinEvictableIdleTimeMillis(Long.parseLong(map.get("minEvictableIdleTimeMillis")));
this.setTestWhileIdle(Boolean.valueOf(map.get("testWhileIdle")));
}
public static ThreadPool getInstance() {
if (pool == null) {
synchronized (ThreadPool.class) {
if (pool == null) {
logger.info("thread pool is initialized.");
pool = new ThreadPool();
}
}
}
return pool;
}
/**
*
* <p>Title: getConfig</p>
* <p>Description: get pool configuration</p>
* @return
*/
public Map<String, String> getConfig() {
Map<String, String> map = new HashMap<String, String>();
Properties props = new Properties();
try {
InputStream in = Thread.currentThread().getContextClassLoader().getResourceAsStream("pool.properties");
props.load(in);
Enumeration en = props.propertyNames();
while (en.hasMoreElements()) {
String key = (String) en.nextElement();
map.put(key, props.getProperty(key));
}
in.close();
} catch (Throwable t) {
logger.error(t.getMessage(), t);
}
return map;
}
}
结果.java
public class Result {
private int result;
public Result(){
}
public int getResult(){
return this.result;
}
public void setResult(int result){
this.result = result;
}
}
测试.java
public class Test implements Runnable {
private static Logger logger = Logger.getLogger("BackgroundLog");
private String name = null;
public Test(String name){
this.name = name;
}
public String getName(){
return this.name;
}
public void setName(String name){
this.name = name;
}
@Override
public void run() {
ThreadPool pool = ThreadPool.getInstance();
for(int i=0;i<1000;i++){
try {
Result result = (Result)pool.borrowObject();
logger.info("numActive: "+ pool.getNumActive()+"\t"+"numIdle: "+pool.getNumIdle());
logger.info("thread "+getName()+" "+i+" borrow object from pool "+result.getResult()+".");
result.setResult(0);
pool.returnObject(result);
logger.info("return object to pool.");
Thread.sleep(100);
} catch (Exception e) {
logger.info("thread "+getName()+" "+i);
e.printStackTrace();
}
}
}
public static void main(String[] args) {
for(int i=0;i<50;i++){
Thread t = new Thread(new Test("t"+i));
t.start();
}
}
}
接下来是配置属性:
接下来是 Jprofiler 的线程视图,当它有 4 个线程时:
Test.java 运行几分钟后,一些线程一直被阻塞,只有一个仍在运行但不打印任何日志。我不太了解线程的事情。谁能解释为什么?如何避免线程被阻塞?