How to run Java from Cygwin

问题:

I'm trying to write a BASH script to get my Java program to run(common issue, right?). I just can't quite get it to work. After many edits, here's how I am trying to set the classpath and then execute the program:

java -classpath 'cygpath -u "/cygdrive/c/Projects/common/lib/rome-1.0.jar:/cygdrive
/c/Projects/common/lib/jdom-1.0.jar:/cygdrive/c/Projects/common/lib/jsoup-1.6.1.jar:
/cygdrive/c/Projects/common/lib/mysql-connector-java-5.1.18-bin.jar:/cygdrive/c/Projects
/Freereader/bin/"' com.free.syndication.SQLfeeder

Sorry the the jumble, I'm just trying to do everything at once. It tells me that the main class of my program cannot be found!((

Any ideas?

回答1:

• Java classpath uses semicolon as the token separator.
• Use backticks instead of single quotes

Try:

java -classpath `cygpath -u "/cygdrive/c/Projects/common/lib/rome-1.0.jar;/cygdrive
/c/Projects/common/lib/jdom-1.0.jar;/cygdrive/c/Projects/common/lib/jsoup-1.6.1.jar;
/cygdrive/c/Projects/common/lib/mysql-connector-java-5.1.18-bin.jar;/cygdrive/c/Projects
/Freereader/bin/"` com.free.syndication.SQLfeeder

回答2:

• In bash, the syntax $(command) is clearer than the backticks `command`
• cygpath has a -p option to convert PATH-like values (as opposed to single path names) between Windows and Unix, i.e.
  • cygpath -pu 'C:\Users\me\bin;C:\Users\me\project\bin' will give /cygdrive/c/Users/me/bin:/cygdrive/c/Users/me/project/bin
  • cygpath -pw will do the same in the opposite direction

Note that cygpath -u "/cygdrive/c" (as in your question) will not change anything, since the directory name is already in the desired (Unix) syntax. You could omit it just as well.

So, the command becomes:

CP="C:/Projects/common/lib/rome-1.0.jar;C:/Projects/common/lib/jdom-1.0.jar;C:/Projects/common/lib/jsoup-1.6.1.jar;
C:/Projects/common/lib/mysql-connector-java-5.1.18-bin.jar;C:/Projects
/Freereader/bin"
# for a Windows Java binary:
java -classpath "$(cygpath -pw "$CP")" com.free.syndication.SQLfeeder 
# for a Unix Java binary:
java -classpath "$(cygpath -pu "$CP")" com.free.syndication.SQLfeeder 

Alternatively, you can start with a Unix-style class path, but the commands stay the same. In either case, you can of course omit the call to cygpath if the class path is already in the desired syntax.

回答3:

Don't you need backticks?

java -classpath `cygpath -u "/cygdrive/c/Projects/common/lib/rome-1.0.jar:/cygdrive
/c/Projects/common/lib/jdom-1.0.jar:/cygdrive/c/Projects/common/lib/jsoup-1.6.1.jar:
/cygdrive/c/Projects/common/lib/mysql-connector-java-5.1.18-bin.jar:/cygdrive/c/Projects
/Freereader/bin/"` com.free.syndication.SQLfeeder

回答4:

1. You must use backticks ( '`' symbol ) or $(cmd) bash sytax to substitute cmd output
2. java do not understand unix- (cygwin-) style paths, only windows-style.

And at last first link in google answers you question

回答5:

The main cause of the issue is NOT the backtic but instead the issue of colon versus semi-colon. Since in cygwin, the java running there is for DOS/Windows environment it is expecting ';' as the path separator.

While backtic does help, the main root cause of the issue must be emphasize the difference between ':' and ';' when Java is in Unix or in Windows environment.