-1
나는 미래에이 줄을 비교하기 위해 readLine() 출력을 변수 (단 한 줄만 포함)에 저장하려고합니다. 그러나 변수는 그 값을 변경하지 마십시오 :readLine()을 저장할 수 없습니다. 문자열 변수
try {
String VersName = "src/bin/version.txt";
BufferedReader br = null;
br = new BufferedReader(new FileReader(VersName));
URL url = new URL("ftp://31.130.206.175/current_versions/vers");
// read text returned by server
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
System.out.println(br.readLine());
System.out.println(in.readLine());
String aa = null;
String bb = null;
aa = br.readLine();
bb = in.readLine();
System.out.println("***" + aa + "***" + bb + "***");
in.close();
br.close();
} catch (MalformedURLException e3) {
System.out.println("Malformed URL");
} catch (IOException e4) {
System.out.println("I/O Error");
}
출력 :
0.0.0
0.1.0
***null***null***
내가 문자열로 은밀한하기 위해 노력하고있어 (AA = br.readLine의 toString()을();.), 나는 예외가 있습니다 :
0.0.0
0.1.0
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Launcher.SimpleSwingBrowser$3.actionPerformed(SimpleSwingBrowser.java:209)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6535)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6300)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4891)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2750)
at java.awt.Component.dispatchEvent(Component.java:4713)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
변수를 저장할 수있는 방법이 있습니까?
감사합니다.
데이터는 왜'내의 readLine()'네 번 호출 한 줄이 포함 된 경우? 그러나 당신이 제공 한 결과는 분명히 두 줄을 보여줍니다 : 당신의 설명? 그리고 무엇이'안에 '이며, 그것이 널이 아니라는 당신의 믿음의 근거는 무엇입니까? – EJP
@OP 질문을 파손하지 마십시오. – EJP