起動時にNumberFormatExceptionが、客のパソコンで出る。

起動時には呼び出されないはずのメソッドでエラーになります。
自分のパソコンでは正常に実行できます。
このアプリは、Twitterのツイートをブログに掲載するためのHTMLタグを複数一括で作成するものです。

java
1import java.awt.*;
2import java.awt.event.*;
3import javax.swing.*;
4import java.net.*;
5import java.io.*;
6import java.util.*;
7import twitter4j.*;
8import twitter4j.auth.*;
9import twitter4j.conf.*;
10import mine.*;
11
12class Marcy extends JFrame implements ActionListener, KeyListener{
13	
14	public String[] keys = {
15		"*************", //Consumer Key (API Key)
16		"*****************", //Consumer Secret (API Secret)
17		"*************",
18		"*****************"
19	};
20	
21	Twitter twitter;
22	static RequestToken requestToken;
23	JTextField url;
24	JTextArea log;
25
26	public static void main(String[] args){
27
28		Marcy f = new Marcy();
29		f.setTitle("Marcy");
30		f.setDefaultCloseOperation(EXIT_ON_CLOSE);
31		f.setVisible(true);
32	}
33
34	Marcy(){
35
36		URL iconUrl = getClass().getResource("icon.png");
37		setIconImage(new ImageIcon(iconUrl).getImage());
38
39		//displaySize
40		GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
41		DisplayMode dm = env.getDefaultScreenDevice().getDisplayMode();
42		int width = dm.getWidth();
43		int height = dm.getHeight();
44		setBounds(width / 2 - 250, height / 2 - 125, 500, 250);
45
46		JPanel base = new JPanel();
47		base.setLayout(null);
48		add(base);
49
50		url = new JTextField();
51		url.setBounds(0, 0, 490, 25);
52		url.addKeyListener(this);
53		base.add(url);
54
55		JButton button = new JButton("取得");
56		button.setBounds(0, 25, 80, 30);
57		button.addActionListener(this);
58		base.add(button);
59		
60		log = new JTextArea();
61		JScrollPane sp = new JScrollPane(log);
62		sp.getVerticalScrollBar().setUnitIncrement(6);
63		sp.setBounds(0, 60, 490, 150);
64		base.add(sp);
65		
66		String openUrl = null;
67		try{
68			twitter = new TwitterFactory().getInstance();
69			twitter.setOAuthConsumer(keys[0], keys[1]);
70			requestToken = twitter.getOAuthRequestToken();
71			openUrl = requestToken.getAuthorizationURL();
72			AccessToken accessToken = new AccessToken(keys[2], keys[3]);
73			twitter.setOAuthAccessToken(accessToken);
74		} catch(TwitterException e){
75			
76			e.printStackTrace();
77		}
78	}
79
80	public void actionPerformed(ActionEvent e){
81
82		getHtml();
83	}
84
85	public void keyPressed(KeyEvent e){
86
87		if(e.getKeyCode() == 10){
88
89			getHtml();
90		}
91	}
92
93	public void keyTyped(KeyEvent e){}
94	public void keyReleased(KeyEvent e){}
95
96	public void getHtml(){
97
98		if(!url.getText().equals("")){
99
100			addLog("wait...");
101
102			try{
103
104				String urltext = url.getText().substring(url.getText().lastIndexOf("/status/") + 8);
105				if(urltext.endsWith("/")) urltext = urltext.substring(urltext.length() - 1);
106				addLog("TweetID is " + urltext);
107				Status status = twitter.showStatus(Long.parseLong(urltext));
108
109				File fl = new File(status.getUser().getScreenName() + " - " + urltext + ".html");
110				int i = 0;
111				while(fl.exists()){
112
113					fl = new File(status.getUser().getScreenName() + " - " + urltext + " (" + i + ").html");
114					i ++;
115				}
116				try{
117					fl.createNewFile();
118				} catch(IOException ioe){
119
120					ioe.printStackTrace();
121				}
122
123				/*NetFileReader nfr = new NetFileReader(url.getText());
124				String html = "";
125				String line = null;
126				boolean addLine = false;
127				while((line = nfr.readLine()) != null){
128
129					if(line.indexOf("<small class=\"time\">") >= 0){
130
131						addLine = true;
132					}
133					if(addLine){
134
135						html += line;
136					}
137					if(line.indexOf("</small>") >= 0){
138
139						addLine = false;
140					}
141				}
142				ArrayList<Status> rep = new ArrayList<Status>();
143				while(html.indexOf("/status/") >= 0){
144
145					html = html.substring(html.indexOf("/status/") + 8);
146					Long id = Long.parseLong(html.substring(0, html.indexOf("\"")));
147					rep.add(twitter.showStatus(id));
148					addLog("id : " + id);
149					if(html.indexOf("<small class=\"time\">") >= 0){
150
151						html = html.substring(html.indexOf("<small class=\"time\">"));
152					}
153				}
154				try(PrintWriter out = new PrintWriter(new OutputStreamWriter(new FileOutputStream(fl, true),"UTF-8"))){
155
156					int count = 1;
157					out.println("<html lang=\"ja\"><meta charset=\"utf-8\">");
158					out.println("<head>");
159					out.println("<script type=\"text/javascript\">");
160					out.println("	function addTweet(elm){");
161					out.println("");
162					out.println("		var nh = document.getElementById(\"newhtml\");");
163					out.println("		var nhText = elm.innerHTML.substring(elm.innerHTML.indexOf(\"&lt;div\"));");
164					out.println("		nhText = nhText.substring(0, nhText.length - 13);");
165					out.println("		nh.innerHTML += nhText + \"\n\";");
166					out.println("	}");
167					out.println("</script>");
168					out.println("<style type=\"text/css\">");
169					out.println("	.addButton::before{");
170					out.println("		content: '↓このツイートを追加';");
171					out.println("");
172					out.println("		font-size: 1.3em;");
173					out.println("		border: solid 1px black;");
174					out.println("		background-color: cyan;");
175					out.println("		box-shadow: 2px 2px 2px gray;");
176					out.println("	}");
177					out.println("	.addButton:hover{");
178					out.println("		font-size: 1.1em;");
179					out.println("	}");
180					out.println("</style>");
181					out.println("</head>");
182					out.println("<body>");
183					out.println("<textarea id=\"newhtml\" style=\"position: fixed; width: 40%; left: 55%; height: 90%;\"></textarea>");
184					out.println("<div class=\"addButton\" onclick=\"addTweet(this)\">");
185					out.println("<textarea style=\"display: none;\">&lt;div align=\"center\"&gt;" + getTweetUrl(status, true) + "&lt;/div&gt;</textarea>");
186					out.println("</div>");
187					out.println(getTweetUrl(status, false));
188
189					for(Status sts : rep){
190
191						if(sts.getInReplyToStatusId() == Long.parseLong(urltext)){
192
193							out.println("<div class=\"addButton\" onclick=\"addTweet(this)\">");
194							out.println("<textarea style=\"display: none;\">&lt;div align=\"center\"&gt;" + getTweetUrl(sts, true) + "&lt;/div&gt;</textarea>");
195							out.println("</div>");
196							out.println(getTweetUrl(sts, true));
197							count ++;
198						}
199					}
200					out.println("</body></html>");
201					addLog("count : " + count);
202					addLog("finish.");
203				} catch(IOException ioe){
204
205					ioe.printStackTrace();
206				}*/
207			} catch(TwitterException ex){
208
209				ex.printStackTrace();
210			} catch(Exception ex){
211
212				ex.printStackTrace();
213			}
214		} else addLog("Text is Nothing.");
215	}
216
217	public void addLog(String str){
218
219		System.out.println("log: " + str);
220		log.setText(log.getText() + str + "\n");
221		log.paintImmediately(log.getX(), log.getY(), log.getWidth(), log.getHeight());
222		log.repaint();
223	}
224
225	public String getTweetUrl(Status status, boolean repIn){
226
227		String conv = "";
228		if(repIn){
229
230			conv =  "data-conversation=\"none\"";
231		}
232		String str = "<blockquote class=\"twitter-tweet\" " + conv + " data-lang=\"ja\"><p lang=\"ja\" dir=\"ltr\">" + status.getText() + "</p>&mdash; " + status.getUser().getName() + " (@" + status.getUser().getScreenName() + ") <a href=\"https://twitter.com/" + status.getUser().getScreenName() + "/status/" + status.getId() + "\">" + status.getCreatedAt().toString() + "</a></blockquote><script async src=\"https://platform.twitter.com/widgets.js\" charset=\"utf-8\"></script>";
233		return str;
234	}
235}

エラーは、getHtmlメソッド内の、Status status = twitter.showStatus(Long.parseLong(urltext));の、Long.parseLong(urltext)で発生していますが、そもそもgetHtmlメソッドは、「取得」ボタンを押すかJTextFiedでEnterキーを押さないと実行されません。
以下が、Jarファイルを実行してもらった時のエラーメッセージです。
行数は現在少々変わっていますが同じ文です。

C:\Users\user\Desktop\Marcy>java -jar Marcy.jar
java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Long.parseLong(Unknown Source)
at java.lang.Long.parseLong(Unknown Source)
at Marcy.getHtml(Marcy.java:155)
at Marcy.actionPerformed(Marcy.java:130)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
以下省略

java.lang.NumberFormatException: For input string: ""
と書いてありますが、なにも入力されずに実行された時にはif文でif(!url.getText().equals("")){としてあります。