html parse高手进

我想用html parser修改htm为什么不行，通过程序连接href时，说UnknownHostException，运行程序报错如下：
java.net.UnknownHostException: help.sap.com
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
at java.net.Socket.connect(Socket.java:516)
at java.net.Socket.connect(Socket.java:466)
at sun.net.NetworkClient.doConnect(NetworkClient.java:157)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:365)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:477)
at sun.net.www.http.HttpClient. <init>(HttpClient.java:214)
at sun.net.www.http.HttpClient.New(HttpClient.java:287)
at sun.net.www.http.HttpClient.New(HttpClient.java:299)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:795)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:747)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:672)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:916)
at java.net.URL.openStream(URL.java:1007)
at info.monitorenter.cpdetector.io.UnicodeDetector.detectCodepage(UnicodeDetector.java:165)
at info.monitorenter.cpdetector.io.CodepageDetectorProxy.detectCodepage(CodepageDetectorProxy.java:132)
at com.anycase.admin.util.CharsetDetector.getCharset(CharsetDetector.java:40)
at org.apache.jsp.dojo