使用批处理脚本编译项目并包含库

Question

In CMD I compile project with including libraries

java -cp app.jar;libs/*;. com.app.Main

and it works, but I want create BATCH script, which do exactly the same. I create test.bat and put code like below:

@ECHO off

java -cp app.jar;libs/*;. com.app.Main

PAUSE

But when I run the test.bat the CMD was shown and there is information "Error: Could not find or load main class com.app.Main".

BATCH script is located at the same folder as app.jar and libs folder.

What is wrong with this batch script?

Answer 1

Probably the characters on the compile line are significant to the batch interpreter; try putting the classpath in double quotes.

Answer 2

After Java 6, Classpaths could be built by using wildcard characters .

You can create a directory named classpath and put your JARs inside it. Then you can create your .bat file like this:

@ECHO off
java -cp .;classpath/* com.app.Main
pause

You should have a structure like this:

com
`---app
    `---Main.java
classpath
`---your-crital-code-1.0.jar
compile.bat

---

I see that a lot of people are asking this question on StackOverflow, so here is a little tip for you guys.

I usually avoid using the cd command, as it may create some hassle. In windows, you can Shift + Right Click to open a command window in a particular directory.

I always prefer relative paths over absolutes, so that I don't get into hassle of managing long paths.

Here is a little program that deals with this kind of problem. You can always refer to and contribute to it so that we can make good examples for Java beginners :)