在 Eclipse 上运行的 Java 项目，但在使用批处理时出错

Question

I made a project for my uni. where I need to pass command line arguments. It is running perfectly fine on eclipse but when I run it using a batch file.

my batch file looks like

set path = "c:\Program Files\Java\jdk-14.0.2\bin";
javac FileHand.java
java FileHand DirectBuffer 1024 Sample.txt
pause

Answer 1

Do not set %path% at all. If you want to 'hardcode' the full path to java, then do so; write C:\\program files\\....\\javac , or SET JAVA_LOC=... and then %JAVALOC%\\javac . But, this is clearly is not needed; you messed up your SET PATH statement and yet javac is being invoked, so, you should probably just remove the entire 'set path' line.

The problem is classpath. There is a file named DirectBuffer.class. It is somewhere - you said that 'it works in eclipse', which means eclipse can find this file, because you told it where it is. You need to tell javac where it is. You do this as follows:

javac -cp LOC1;LOC2;LOC3 FileHandjava

java -cp .;LOC1;LOC2;LOC3 FileHand DirectBuffer 1024 Sample.txt

where LOC1 is a path. It can be a directory, or a jar file. Your question does not make this clear, but let's say DirectBuffer' is in the com.foo.pkg package (so, you have import com.foo.pkg.DirectBuffer;` in your source file), then:

either:

cd (whatever you put for LOC1)
cd com\foo\pkg
dir

should print, amongst other things, 'DirectBuffer.class', or, if LOC1 is a jar file:

jar tvf (the jar file listed in LOC1)

should print com/foo/pkg/DirectBuffer.class , amongst other things. You've already told eclipse this, so now find those places where you did that and tell javac about it.