Java 代码在 Windows 中有效，但在 Linux（Fedora 或 Ubuntu）中无效

Question

So I have this small Java project for study purposes where I am learning how to call functions from other java files and reference them with import. Everything works as inteded in Windows and I'm happy with it, but I just tried to work in the same project using Fedora and Ubuntu, and seems like the imports and package references just don't work.

I get this trying to compile main java file:

$ javac Ejercicio01.java 
Ejercicio01.java:3: error: package actividad05.introduceDatos does not exist
import static actividad05.introduceDatos.Pregunta.*;
                                        ^
Ejercicio01.java:4: error: package actividad05.operaciones does not exist
import static actividad05.operaciones.Valores.*;
                                     ^
Ejercicio01.java:5: error: package actividad05.operaciones.algebraicas does not exist
import static actividad05.operaciones.algebraicas.Operaciones.*;
                                                 ^
Ejercicio01.java:6: error: package actividad05.operaciones.geometricas does not exist
import static actividad05.operaciones.geometricas.Operaciones.*;
                                                 ^
Ejercicio01.java:13: error: cannot find symbol
            opcion = pideEntero("\nElija una opcion:"
                     ^
  symbol:   method pideEntero(String)
  location: class Ejercicio01
Ejercicio01.java:25: error: cannot find symbol
                        muestraPi();
                        ^
  symbol:   method muestraPi()
  location: class Ejercicio01
Ejercicio01.java:28: error: cannot find symbol
                        muestraValorAleatorio();
                        ^
  symbol:   method muestraValorAleatorio()
  location: class Ejercicio01
Ejercicio01.java:31: error: cannot find symbol
                        double num = pideDouble("Introduzca un valor: ");
                                     ^
  symbol:   method pideDouble(String)
  location: class Ejercicio01
Ejercicio01.java:32: error: cannot find symbol
                        muestraSeno(num);
                        ^
  symbol:   method muestraSeno(double)
  location: class Ejercicio01
Ejercicio01.java:35: error: cannot find symbol
                        num = pideDouble("Introduzca un valor: ");
                              ^
  symbol:   method pideDouble(String)
  location: class Ejercicio01
Ejercicio01.java:36: error: cannot find symbol
                        muestraCoseno(num);
                        ^
  symbol:   method muestraCoseno(double)
  location: class Ejercicio01
Ejercicio01.java:39: error: cannot find symbol
                        muestraRaizCuadrada();
                        ^
  symbol:   method muestraRaizCuadrada()
  location: class Ejercicio01
Ejercicio01.java:42: error: cannot find symbol
                        double base = pideDouble("Introduzca base: ");
                                      ^
  symbol:   method pideDouble(String)
  location: class Ejercicio01
Ejercicio01.java:43: error: cannot find symbol
                        double exp = pideDouble("Introduzca exponente: ");
                                     ^
  symbol:   method pideDouble(String)
  location: class Ejercicio01
Ejercicio01.java:44: error: cannot find symbol
                        calculaPotencia(base, exp);
                        ^
  symbol:   method calculaPotencia(double,double)
  location: class Ejercicio01
15 errors

My main Java file references the other functions like this:

package actividad05.main;

import static actividad05.introduceDatos.Pregunta.*;
import static actividad05.operaciones.Valores.*;
import static actividad05.operaciones.algebraicas.Operaciones.*;
import static actividad05.operaciones.geometricas.Operaciones.*;

public class Ejercicio01 {

Meaning that Ejercicio01.java is in the folder src/actividad05/main, and the functions imported are in src/actividad05/introduceDatos/Pregunta.java etc, etc.

Answer 1

My first thought is that this is probably a classpath problem. Check where your source code is (.java files) and where you compile them to (.class files). Then check how you are trying to run the application, is the location of all the.class files on the classpath? In this case it has little to do with the OS difference, but with compilation and execution commands and file locations.

A problem which sometimes occurs when running compiled code on another OS is that the JDK or JRE has a different vendor or version. Are you using the Oracle or OpenJDK? Which version? If the version is different, even compilation might run into trouble because some Java features are different.

But the above output points in the direction of the first issue.

EDIT: the problem that the package is not found could mean that you don't have the.java file under the directories matching the package names, or that you are not calling the compiler on the root package (the source directory).

Check out: https://www.webucator.com/how-to/how-compile-packages-java.cfm