[Java diary] Frequent mistakes and questions published on the Moon Palace 2004-11-21 23:13:47
1 can not read xxx.java
First look at whether your file is saved as .java.txt type (the expansion name in the right point file) Remember to save the file name .java plus quotation marks.
2 Exception in thread "main" java.lang.noclassdeffounderroe:
Explain that you have not joined in your classpath.
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7233 <; / a> 3 Where is the difference between "==" and "equals ()"? http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 16630 & Show = 0 <; / a> 4 StringBuffer S1 = New StringBuffer ("a"); StringBuffer S2 = New StringBuffer ("a"); S1.EQUALS (S2) / / Why is False String S1 = New String ("a"); String S2 = New String ("a"); S1.Equals (S2) / / Why is TRUE
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 14935 <; / a> String, and StringBuffer difference ; http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7007 <; / a> 5 Java web start? http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 15868 <; / a> 6 Trim () function usage
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 10515 <; / a> 7 How to extract the system time? http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 734 <; / a> 8 How to make the window always in front
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 16587 <; / a> 9 Date display formatted http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 16750 <; / a> How to convert the public calendar and lunar calendar? ? ? ? ? ? ? ? ?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7101 <; / a> 10 What is the difference between static and non-static nesses?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4721 <; / a> 11 How to judge the input Dongdong is a character or a number?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4687 <; / a> 12 finalize () and system.gc ()
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4656 <; / a> 13 How to enter 2 on the keyboard .... actually printed 50 ??? system.in.read () usage ; http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4605 <; / a> 15 types of polymorphism
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4737 <; / a> 16 If a program contains multiple .java files, and they are associated with each other. Now we have to compile them, what should I do! http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 5000 <; / a> 17 Interface and class discussion http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 5007 <; / a> 18 How is the Chinese characters turn into code?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4991 <; / a> 19 Can you read the contents of Jtextarea?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4785 <; / a> How to add a string of 20 days of 20 days
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4812 <; / a> 21 "THIS" function and what is the use? http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 4780 <; / a> 22 Questions about polymorphism and multi-level inheritance
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7154 <; / a> 23 What is an object-oriented design idea?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7069 <; / a> 24 About a problem with the inner class of Java
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 712 <; / a> 25 How to get the IP of this unit
; http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7151 <; / a> What is the difference between THROW and THROWS?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7005 <; / a> 27 Why is this problem with an abstract class in Java? ? What is his role? What are the advantages? ? ; http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 160 <; / a> 28 Final, private defines a variable
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7042 <; / a> 29 Java modifier and character output
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7054 <; / a> 30 What is anonymous? http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7070 <; / a> 31 How to run another executable file on the hard disk in an application?
http://www.chinajavaworld.net/forum/topic.cgi? Forum = 20 & Topic = 7066 <; / a> 32 How to take this date ??? I want to get this format: YYYY-MM - DD how to make? ? ?
