ClassNotFoundException: org.apache.commons.math3.distribution.NormalDistribution-CodePudding

I have downloaded the apache match package to my machine and compiled the code below without error, but when I run the class I got the error "ClassNotFoundException: org.apache.commons.math3.distribution.NormalDistribution"

import org.apache.commons.math3.distribution.NormalDistribution;

public class CumulativeProbability {
    private static NormalDistribution nd;

    public static void main(String[] args) {
        nd = new NormalDistribution(100.30 , 232.45);
        System.out.println(nd.cumulativeProbability(3000));
        
        nd = new NormalDistribution(50.3, 10.1);
        System.out.println(nd.inverseCumulativeProbability(0.7));
    }
}

The error message:

C:\Distnormal>java CumulativeProbability Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/math3/distribution/NormalDistribution at CumulativeProbability.main(CumulativeProbability.java:9) Caused by: java.lang.ClassNotFoundException: org.apache.commons.math3.distribution.NormalDistribution

Trying with the command: C:\Distnormal>java -cp "C:\Distnormal\commons-math3-3.6.1.jar" CumulativeProbability Error: Could not find or load main class CumulativeProbability

below how I'm compiling: C:\Distnormal>javac -cp "C:\Distnormal\commons-math3-3.6.1.jar" CumulativeProbability.java

I double-checked everything but could not find where the error is.

I already double-checked the source code, the jar file but not able to fix the error.

CodePudding user response：

I tried your main program and I can compile it and run it successfully with commons-math3-3.6.1.jar. I'm working on Ubuntu Linux.

Compile:

$ javac -d . -cp commons-math3-3.6.1/commons-math3-3.6.1.jar CumulativeProbability.java

The -d . means for javac to write .class files into . (i.e., current working directory).

Run:

$ java -cp commons-math3-3.6.1/commons-math3-3.6.1.jar:. CumulativeProbability
1.0
55.5964451783512

Note that I put . on the classpath, otherwise java doesn't find CumulativeProbability.

I think it must be a problem with the -cp option for you. Try this: write the path as either "C:\Distnormal\commons-math3-3.6.1.jar" (i.e. with two backslash characters) or "C:/Distnormal/commons-math3-3.6.1.jar" (i.e. with one forward slash character).