java - Apache PoolingHttpClientConnectionManager 抛出非法状态异常

Question

这是我的使用方法-

private static final PoolingHttpClientConnectionManager connPool;

static {

        connPool = new PoolingHttpClientConnectionManager();
        // Increase max total connection to 200
        connPool.setMaxTotal(200);//configurable through app.properties
        // Increase default max connection per route to 50
        connPool.setDefaultMaxPerRoute(20);//configurable through app.properties

}

CloseableHttpClient httpClient = HttpClients.custom()
                .setConnectionManager(connPool) .build();

此外，我还在 http GET 周围放置了一个 finally block -

finally {
            try {
                httpClient.close();
            } catch (IOException e) {
                LOGGER.error(e.getMessage());   
            }
        }

这是我的堆栈跟踪 -

java.lang.IllegalStateException: Connection pool shut down
    at org.apache.http.util.Asserts.check(Asserts.java:34)
    at org.apache.http.pool.AbstractConnPool.lease(AbstractConnPool.java:169)
    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.requestConnection(PoolingHttpClientConnectionManager.java:217)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:157)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:194)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:85)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:108)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:186)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106)
    at com.A.B.C.CustomHttpClient.doGETAndValidate(CustomHttpClient.java:44)
    at com.A.B.C.SiteMonitorTask.monitorAndUpdateEndPoints(SiteMonitorTask.java:48)
    at com.A.B.C.SiteMonitorTask.run(SiteMonitorTask.java:37)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

我正在使用 Quartz 来安排监视 Http 端点的工作。这是我的连接池配置

totalMaxHttpConn=200
maxHttpConnPerRoute=20

Maven 依赖..工件版本

httpclient 4.3.1
httpcore 4.3.1

编辑 - 好吧，通过在 finally block 中不关闭 CloseableHttpClient 解决了问题。任何人都可以说出为什么它会这样吗？ 为什么关闭客户端后连接池会关闭？

上面的closeablehttpclient是池的句柄而不是单个conn

Answer 1

在 4.4 版中，方法 setConnectionManagerShared(boolean) 被添加到 HttpClientBuilder。

如果将其设置为 true，客户端将不会关闭连接管理器。

HttpClients.custom()
            .setConnectionManager(Util.getConnectionManager()) // shared connection manager
            .setConnectionManagerShared(true)