We have the complete file, ch10_01.java, and we're ready to run it. The first step is compiling it into a bytecode file, ch10_01.class. To compile ch10_01.java, you use the Java tool javac, the Java compiler (on Windows machines, this program is called javac.exe and is located in the bin subdirectory). Here's how you use javac in general (all the arguments here are optional, and I'll place them in square brackets to indicate that, which is the convention Sun itself uses in the java documentation): javac [ options ] [ sourcefiles ] [ files ] Here are the arguments to javac:
In this case, I'll compile ch10_01.java with this command: %javac ch10_01.java The Java compiler, javac, compiles the file ch10_01.java ( assuming that there are no errors), translating it and creating a new file named ch10_01.class. If there are errors, the Java compiler will tell you what they are, including what line of code is wrong, as in this case, in which I've forgotten the name of the println method and tried to use one called printText : %javac ch10_01.java ch10_01.java:5: Method printText(java.lang.String) not found in class java.io.Print Stream. System.out.printText("Welcome to Java"); ^ 1 error At this point, we've created the file ch10_01.class, the bytecode file that Java will need to run the application. This bytecode file will run unchanged on any system that supports Java. So how do you actually run ch10_01.class? I'll take a look at that in the next section. |