class path question

[Rajiv Chopra]

-classpath /com:/foo:.
is not the same as
-classpath .:/foo:/com


Can anyone explain the difference. k&b 798 page.(unable to understand).

[Charles Chikito]

-classpath /com:/foo:.
is not the same as
-classpath .:/foo:/com

They are not same.


Whenever javac or java is invoked using -classpath /com:/foo:.
it will look for the required classes in /com first. If not found, it goes to /foo and look for the same. If not found, it searches the current directory.

If it managed to find in /com it won't search inside /foo. Similarly, if it cannot find in /com but managed to find the class in /foo, it won't search in the current directory. Again if the class is not found in /foo, it will search in the current directory. If the class is not found in the current directory, the compilation will fail.

So in .:/foo:/com, the sequence of searching the class file starts from current directory. If not found in the current directory, it goes to the /foo. If not found in /foo, then it look in the /com.

Again, if it managed to find in the current directory, it stops there. The process continues to /foo if the class is not available in the current directory. The /com will be searched if the class file is not available in the /foo directory. If the class file is not found in the /com directory, then the compilation will fail.

HTH.

_charles

[Wouter Oet]

Just read the sentence above it . Because the classpath is read from left to right the class that is first found will be used.

Example:

ClassPathTest.java

{
	public static void main(String... args)
	{
		new Child().say();
	}
}

test1/Child.java

public class Child {   
    void say() {   
        System.out.println("test1/Child.java");   
    }   
}   

test2/Child.java

public class Child {   
    void say() {   
        System.out.println("test2/Child.java");
    }   
}   

java -cp .:test1/:test2/ ClassPathTest
Output: test1/Child.java
java -cp .:test2/:test1/ ClassPathTest
Output: test2/Child.java

[Rajiv Chopra]

Wouter Oet wrote:Just read the sentence above it . Because the classpath is read from left to right the class that is first found will be used.

Example:

ClassPathTest.java

{
	public static void main(String... args)
	{
		new Child().say();
	}
}

test1/Child.java

public class Child {   
    void say() {   
        System.out.println("test1/Child.java");   
    }   
}   

test2/Child.java

public class Child {   
    void say() {   
        System.out.println("test2/Child.java");
    }   
}   

java -cp .:test1/:test2/ ClassPathTest
Output: test1/Child.java
java -cp .:test2/:test1/ ClassPathTest
Output: test2/Child.java

Thanks you very much! I am using windows so i think : should be ; for me.

Thanks for both comments above again.