WEBVTT

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In this demo I'm going to show you how to 

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compile Java source files 

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at the Windows command prompt 

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without using BlueJ.

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To add a source code can be compiled 

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at the command prompt using the javac command 

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that's available if you have the Java SDK 

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installed on your computer. 

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When BlueJ compiles a class 

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it uses the javac command, 

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it just hides the details from you. 

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I have a folder containing Java source files 

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for all the classes in the adventure game programme. 

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I can list the contents of that folder 

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and you can see the source files there. 

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Let's try compiling the Item class, 

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type the command javac then Item.java and return. 

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I don't get any message which is a good thing 

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because javac only will give me messages 

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if there are compilation errors. 

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Lets list the contents of the folder now 

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and you can see there's a new file item.class 

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which contains the compiled item class. 

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I can compile all the classes in the folder 

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at once using a wildcard. 

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Type javac *.java and return and again 

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there's no message so compilation has been successful. 

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If I list the contents of the folder you can see that 

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there's now a class file for everyone of the source files. 

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Finally, I'm going to run the programme. 

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In the previous demo 

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I showed you how to run a Java programme 

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packaged as a jar file and that's

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normally the most convenient way to run a programme. 

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However, you can run a programme 

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by using the Java command and specifying 

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the name of the class that contains the main method. 

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This will work if compiled class files are available 

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for all the classes that the programme needs. 

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So lets try that, 

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java and the name of the class with the main method 

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is Game and enter and a welcome message is shown 

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and we can just 

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go through the rest of the programme as before.