URL未知主机异常

Question

I was trying this piece of code.Why would this give the java.net.UnknownHostException: www.oracle.com .The URl is pretty correct.Isn't it?

import java.net.*;
import java.io.*;

public class Urlread {
    public static void main(String[] args) throws Exception {
        URL oracle = new URL("http://www.oracle.com/");
        URLConnection yc = oracle.openConnection();
        BufferedReader in = new BufferedReader(new InputStreamReader(
                                    yc.getInputStream()));
        String inputLine;
        while ((inputLine = in.readLine()) != null) 
            System.out.println(inputLine);
        in.close();
    }
}

Answer 1

There is nothing wrong with your code. You just need to check the internet connection on the machine from where you are trying to run this code. I am able to successfully run the shared code and here is the snippet of output:

var _U = "undefined"; var g_HttpRelativeWebRoot = "/ocom/"; var SSContributor = false; var SSForceContributor = false; var SSHideContributorUI = false; var ssUrlPrefix = "/us/"; var ssUrlType = "2"; var g_navNode_Path = new Array(); g_navNode_Path[0] = '8'; var g_ssSourceNodeId = "8"; var g_ssSourceSiteId = "ocomen";

var g_strLanguageId = "en";

 <fragmentinstance id="fragment3" fragmentid="ocomheader" library="server:OCOMHEADER"> </fragmentinstance> <fragmentinstance id="fragment4" fragmentid="ocomfooter" library="server:OCOMFOOTER"> </fragmentinstance> <fragmentinstance id="fragment5" fragmentid="sitecatalyst-ocom-standard" 

library="server:SITECATALYST-OCOM-STANDARD">

  </fragmentinstance> <fragmentinstance id="fragment6" fragmentid="ocomhp-commonassets" library="server:OCOMHP-COMMONASSETS"> </fragmentinstance> <fragmentinstance id="fragment7" fragmentid="ATGChat" library="server:ATG_CHAT"> </fragmentinstance> <fragmentinstance id="fragment8" fragmentid="UniversalSiteStudioManager" 

library="server:UNIVERSAL_SITE_STUDIO_MANAGER">

  </ssinfo> </script> 

Oracle | Hardware and Software, Engineered to Work Together

  <!--SS_END_SNIPPET(fragment1,head_tags)--> <!-- 

SS_BEGIN_SNIPPET(fragment6,ocomhp-commonassets)--> .menu-otn {display:none;}

var atg_fName = ""; var atg_lName = ""; var atg_eMail = ""; var atg_company = ""; //If User is logged in if (USER.guid) { //Read user properties from cookie object USER atg_fName = USER.firstname; atg_lName = USER.lastname; atg_eMail = USER.username;

  //Get cookie value ORA_WWW_PERSONALIZE and tokenize it to get value 

for cn (company name) var personalizeCookie = (function(){ var i,x,y,ARRcookies=document.cookie.split(";"); for (i=0;i set to true } if(personalizeCookie != null && trustchk) { var cPair = ""; var cName = "" var cValue = ""; var all_values = personalizeCookie.split( '~' ); for (var i = 0; i < all_values.length; i++ ) { cPair = all_values[i].split( ':' ); cName = cPair[0].replace(/^\\s+|\\s+$/g, ''); if (cName == "cn") { cValue = unescape(cPair[1].replace(/^\\s+|\\s+$/g, '')); break; } } if (cValue.length != 0) { atg_company = cValue; } } }); }

var atg_country = "US";

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Answer 2

如果您在Android上运行，建议您检查INTERNET权限，但是由于情况并非如此，因此您应该检查机器的Internet访问，防火墙，代理，DNS等，当然还要检查您的应用程序的Internet连接。