大约有 7,480 项符合查询结果（耗时：0.0197秒） [XML]
How to check if a string contains only digits in Java [duplicate]
In Java for String class there is a method called matches, how to use this method to check if my string is having only digits using regular expression. I tried with below examples, but both of them returned me false as result.
...
What is the convention for word separator in Java package names?
...n.eng
com.apple.quicktime.v2
edu.cmu.cs.bovik.cheese
References
java.sun.com - Code Conventions/Naming
Note that in particular, anything following the top-level domain prefix isn't specified by the above document. The JLS also agrees with this by giving the following examples:
...
How do I convert from int to String?
...oesn't know about the two methods above (what else might they not know?).
Java has special support for the + operator when used with strings (see the documentation) which translates the code you posted into:
StringBuilder sb = new StringBuilder();
sb.append("");
sb.append(i);
String strI = sb.toSt...
Read url to string in few lines of java code
I'm trying to find Java's equivalent to Groovy's:
11 Answers
11
...
Create a custom event in Java
I want to do something like this in Java but I don't know the way:
4 Answers
4
...
Android: android.content.res.Resources$NotFoundException: String resource ID #0x5
... ID #0x7f0700fd
at android.content.res.Resources.getText(Resources.java:299)
at android.content.res.Resources.getString(Resources.java:385)
at com.juvomobileinc.tigousa.ui.signin.SignInFragment$4.onClick(SignInFragment.java:188)
at android.view.View.performClick(View....
Value of i for (i == -i && i != 0) to return true in Java
...only due to choices that were made regarding the binary storage of ints in Java. Another (bad) solution could for example have been to negate by simply changing the most significant bit and letting the other bits unchanged, this would have avoided this problem with MIN_VALUE but would have made 2 di...
Java Embedded Databases Comparison [closed]
I intend to develop a small (Java) application for managing my finances. I believe I need to use an embedded database, but I have no experience regarding this issue. I tried to look at some of the available products , but I can't decide which one would be more suitable for me. H2 , HSQLDB , Derb...
What happens when a duplicate key is put into a HashMap?
...bject, that object becomes eligible for garbage collection. Additionally, Java returns any previous value associated with the given key (or null if none present), so you can determine what was there and maintain a reference if necessary.
More information here: HashMap Doc
...
Does Java have something like C#'s ref and out keywords?
...
No, Java doesn't have something like C#'s ref and out keywords for passing by reference.
You can only pass by value in Java. Even references are passed by value. See Jon Skeet's page about parameter passing in Java for more deta...