2009年10月30日 · The toString() implementation of java.util.Date does not depend on the way the class is imported. It always returns a nice formatted date. The toString() you see comes from another class. Specific import have precedence over wildcard imports. in this case import other.Date import java.util.* new Date(); refers to other.Date and not java.util.Date. The odd thing is that import other.* import ...

The statement java.util.*; imports all of the java.util package members so that you don't have to use a package member's fully qualified name. According to the JavaDocs here the package java.util Contains the collections framework, legacy collection classes, event model, date and time facilities, internationalization, and miscellaneous utility classes (a string tokenizer, a …

Is it possible to import all java libraries with import *; or import java.*; ?

2014年8月12日 · The import directive is a compiler directive, it tells the compiler where to look for a class and allows to not have to always use fully qualified class names, e.g. java.util.HashMap. But the import directives themselves do not get put into the compiled bytecode files, the compiler compiles the fully qualified name into the .class file.

2011年5月5日 · I would like to get a random value between 1 to 50 in Java. How may I do that with the help of Math.random();? How do I bound the values that Math.random() returns?

2012年10月29日 · Take a look at the java API, and you'll see many classes and interfaces with the same name in different packages. For example: java.lang.reflect.Array java.sql.Array So, if you import java.lang.reflect.* and java.sql.* you'll have a collision on the Array type, and have to fully qualify them in your code. Importing specific classes instead will save you this hassle.

2013年2月15日 · From your link: import java.util.*; The * is a "regular expression operator" that will match any combination of characters. Therefore, this import statement will import everything in java.util. If you have tried entering and running the example program above, you can change the import statement to this one.

2017年12月30日 · If we import with a wildcard, that is the asterisk (*) character, only the direct classes in this package will be imported, not the classes in sub-packages. Thus with an import java.util.*, we import classes like ArrayList, LinkedList and Random.

2008年9月29日 · It is much more convenient and cleaner to use a single statement like import java.awt.*; than to import a bunch of individual classes import java.awt.Panel; import java.awt.Graphics; import java...

2013年12月26日 · import java.util.Scanner directive just allows you to use Scanner class name in code without specifying full path to it. import java.util.* directive allows you to use ALL class names in java.util without a path.