从命令行编译并运行具有复杂文件结构的Java程序

Question

Trying to compile and run my java program from the commandline that is set up a bit weird. The file structure is as follows:

[ROOT]/
|
|____libs/
|    |____myExtraJar.jar
|     
|____src/
     |____main/
          |____com/
               |____example/
                    |____myClass.java

The package is defined at the top of the java file as

package com.example;

I am able to compile the program fine (I think) while in the root folder, using

javac -classpath "/libs/myExtraJar.jar" src/main/com/example/*.java

I don't get any compilation errors (such the ones that occur if I leave off the classpath) and I can see that .class files are being created in the com/example/ folder. However, I can't find any way to run the compiled program. Running

java src/main/com/example/myClass

results in the message

Error: Could not find or load main class src.main.com.example.myClass

Any help would be appreciated.

Answer 1

You need to specify the classpath when you run it, and you also need to use the fully-qualified classname. Like,

java -cp "libs/myExtraJar.jar:src/main" com.example.myClass

Answer 2

Elliot is right. More precisely, you need to add the build directory to your classpath. It is the directory containing your *.class files, and is sometimes named target/ .

$ java -cp "target:lib/myExtraJar.jar" com.example.myClass

Moreover, src/main/com/example/myClass should be com.example.myClass , which is the fully-qualified class name . See http://www.manpagez.com/man/1/java/ for details of the java command.