webmagic 使用官方样例报错，Received fatal alert: protocol

javax.net.ssl.SSLHandshakeException: Received fatal alert: protocol_version at sun.security.ssl.Alert.createSSLException(Alert.java:131) at sun.security.ssl.Alert.createSSLException(Alert.java:117) at sun.security.ssl.TransportContext.fatal(TransportContext.java:311) at sun.security.ssl.Alert$AlertConsumer.consume(Alert.java:293) at sun.security.ssl.TransportContext.dispatch(TransportContext.java:185) at sun.security.ssl.SSLTransport.decode(SSLTransport.java:149) at sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1143) at sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1054) at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:394) at org.apache.http.conn.ssl.SSLConnectionSocketFactory.createLayeredSocket(SSLConnectionSocketFactory.java:436) at org.apache.http.conn.ssl.SSLConnectionSocketFactory.connectSocket(SSLConnectionSocketFactory.java:384) at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:142) at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:376) at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:393) at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236) at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186) at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89) at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110) at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185) at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83) at us.codecraft.webmagic.downloader.HttpClientDownloader.download(HttpClientDownloader.java:85) at us.codecraft.webmagic.Spider.processRequest(Spider.java:404) at us.codecraft.webmagic.Spider.access$000(Spider.java:61) at us.codecraft.webmagic.Spider$1.run(Spider.java:320) at us.codecraft.webmagic.thread.CountableThreadPool$1.run(CountableThreadPool.java:74) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) 12:21:50.888 [main] INFO us.codecraft.webmagic.Spider - Spider github.com closed! 1 pages downloaded.