Java CLASSPATH环境变量上的jar会被忽略

Question

In my ~/.bashrc I export my java CLASSPATH the following way:

CLASSPATH=$CLASSPATH:/home/user/java/libs/apache-ant-1.9.0/lib/*:/home/user/java/MyProject/libs/*

The folder "/home/user/java/MyProject/libs/" contains the following jars:

colt.jar    mysql-connector-java-5.1.22-bin.jar
concurrent.jar  postgresql-8.4-703.jdbc4.jar

When I try to compile a class of my project that imports parts the colt.jar, I get an error message:

/src$ javac visualization/VisualizeCorrelationMatrix.java 
visualization/VisualizeCorrelationMatrix.java:16: cannot access cern.colt.matrix.impl.SparseDoubleMatrix2D
class file for cern.colt.matrix.impl.SparseDoubleMatrix2D not found
        int N = cm.columns();
                  ^

But when compling it the followin way it works without errors:

/src$ javac -cp ".:/home/user/java/MyProject/libs/*" visualization/VisualizeCorrelationMatrix.java

I checked that the paths in the CLASSPATH variable and the manuel optino -cp are 100% identical. Also an echo $CLASSPATH returns the correct path.

Why do I still get this error?

Answer 1

You need to export the new classpath variable in your bashrc line:

export CLASSPATH=$CLASSPATH:/home/user/java/libs/apache-ant-1.9.0/lib/*:/home/user/java/MyProject/libs/*

Also if the shell you are compiling the java in was created before you changed your bashrc file you'll want to reread the bashrc file using source ~/.bashrc .