Computer Science Canada [Tip] Packages |
| Author: | wtd [ Sat May 27, 2006 5:20 pm ] |
| Post subject: | [Tip] Packages |
Learn to use packages well, and learn it early in your Java education. |
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| Author: | cool dude [ Sat May 27, 2006 5:24 pm ] | ||
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by packages do u mean the different things you can import i.e.
i think there are a lot of those where can i find some of them? any links? |
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| Author: | wtd [ Sat May 27, 2006 5:28 pm ] |
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http://java.sun.com. Look at the API references. You should also know how to create your own packages. |
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| Author: | cool dude [ Sat May 27, 2006 5:45 pm ] |
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1) how do u create packages? 2)there are quite a lot of packages there! what are usually the main ones people use? |
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| Author: | MysticVegeta [ Mon May 29, 2006 1:30 pm ] | ||||
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cool dude wrote: by packages do u mean the different things you can import i.e.
i think there are a lot of those where can i find some of them? any links? Packages are actually bundles of classes, so if you import an entire package, you can use any class inside of that package but if you just want to use 1 or more specific classses from a package, then people usually import those classes specifically and not th eentire package... eg: if you import java.io package, you import classes: Quote: BufferedInputStream
BufferedOutputStream BufferedReader BufferedWriter ByteArrayInputStream ByteArrayOutputStream CharArrayReader CharArrayWriter DataInputStream DataOutputStream File FileDescriptor FileInputStream FileOutputStream FileReader FileWriter FilterInputStream FilterOutputStream FilterReader FilterWriter InputStream InputStreamReader LineNumberInputStream LineNumberReader ObjectInputStream ObjectOutputStream ObjectStreamClass OutputStream OutputStreamWriter PipedInputStream PipedOutputStream PipedReader PipedWriter PrintStream PrintWriter PushbackInputStream PushbackReader RandomAccessFile Reader SequenceInputStream StreamTokenizer StringBufferInputStream StringReader StringWriter Writer if you just need 1 of the class say, BufferedInputStream and not hte entire package, then you would go
I may not be the best explainer because I am pretty new to java myself, hopefully wtd will correct me anywhere I made a mistake... |
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| Author: | cool dude [ Mon May 29, 2006 4:29 pm ] |
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wat difference would it make if i just import the whole package? |
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| Author: | wtd [ Mon May 29, 2006 4:42 pm ] |
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Well, let's say you have package foo with class Bar, and package baz with classes Bar, Ninja and Wooble. What happens if you import all of both packages, then try to use the Bar class from package foo? |
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| Author: | rizzix [ Mon May 29, 2006 7:59 pm ] | ||||
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MysticVegeta wrote: Packages are actually bundles of classes, so if you import an entire package, you can use any class inside of that package but if you just want to use 1 or more specific classses from a package, then people usually import those classes specifically and not th eentire package... eg: You Do Not (and Can Not) import packages in Java. You can only import classes
The asterisk (*) represents all classes. If you wish you may import just one particular class from a package.
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| Author: | rizzix [ Mon May 29, 2006 8:16 pm ] |
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Another tip: Following the java naming conventions, all package names should be in lowercase, while Class names should be in word case. (note: package names are not wordcase) As a general rule: avoid underscores. Method and variable names on the other hand are also word case, but they should begin with a lowercase letter. |
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