无法使用完全限定名称从CMD启动Java文件

Question

As per title, I am able to compile the class just fine but I am unable to run it (despite using fully qualified name)

Boss@DESKTOP-F8O3V2Q /cygdrive/c/eclipse/workspace/MVN/3cx-driver/src
$ java com.software._3cx.main.PBXConnection
Error: Could not find or load main class com.software._3cx.main.PBXConnection

PBXConnection.java

package com.software._3cx.main;

public class PBXConnection extends Proxy {

public PBXConnection(ServerSettings settings) {
    super(settings);
}

public static void main(String args[]) {
....

Would this be because of the package name containing _ underscore?

Tree output

C:\eclipse\workspace\MVN\3cx-driver\src>tree
Folder PATH listing for volume OS
Volume serial number is 00000074 D019:C44D
C:.
└───com
    └───software
        └───_3cx
            └───main

DIR:

C:\eclipse\workspace\MVN\3cx-driver\src\com\software\_3cx\main>dir
 Volume in drive C is OS
 Volume Serial Number is D019-C44D

 Directory of C:\eclipse\workspace\MVN\3cx-driver\src\com\software\_3cx\main

06/04/2017  16:31    <DIR>          .
06/04/2017  16:31    <DIR>          ..
06/04/2017  16:22               115 EventProcessor.java
06/04/2017  16:31             1,434 PBXConnection.class
06/04/2017  16:21             1,994 PBXConnection.java
               3 File(s)          3,543 bytes
               2 Dir(s)  355,750,649,856 bytes free

Edit:

Boss@DESKTOP-F8O3V2Q /cygdrive/c/eclipse/workspace/MVN/3cx-driver/src
$ javac -cp C:/Apache/apache-tomcat-7.0.56/lib/orderlycalls.jar com/software/_3cx/main/PBXConnection.java

Boss@DESKTOP-F8O3V2Q /cygdrive/c/eclipse/workspace/MVN/3cx-driver/src
$ java -cp C:/Apache/apache-tomcat-7.0.56/lib/orderlycalls.jar com.software._3cx.main.PBXConnection
Error: Could not find or load main class com.software._3cx.main.PBXConnection

Edit: Its actually Java 7 i am using (i though java 8 was running) but its not

Boss@DESKTOP-F8O3V2Q ~
$ java -version
java version "1.7.0_79"
Java(TM) SE Runtime Environment (build 1.7.0_79-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.79-b02, mixed mode)

Boss@DESKTOP-F8O3V2Q ~
$ javac -version
javac 1.7.0_79

Boss@DESKTOP-F8O3V2Q ~
$ which java
/cygdrive/c/Program Files/Java/jdk1.7.0_79/bin/java

Boss@DESKTOP-F8O3V2Q ~
$ which javac
/cygdrive/c/Program Files/Java/jdk1.7.0_79/bin/javac

Answer 1

Usually on Linux-like systems you would set up your classpath as follows with a colon:

java -cp "somelibrary.jar:." MyMainClass
                         ^

If you however use a Windows java you will get the error you desribed, indicating that java is not able to find the class you specified.

If you ensure that you have a semicolon in your classpath, it should run your main class just fine:

java -cp "somelibrary.jar;." MyMainClass
                         ^

Note that if you use a unix-flavored java, the opposite is the case. You then may need to use : instead of ; .

Note also: while javac doesn't require the . to find the file you want to compile (as you gave it as parameter), java doesn't know where to find your PBXConnection.class -file. You told java that the classpath to search for contains only that orderlycalls.jar . You need to explicitly say where java can also find your actual main-class. So the . is necessary when you want to run your program, but it isn't necessary in your specific case for the compiler.

Answer 2

Try the following. It will work:

set CLASSPATH=%CLASSPATH%;C:\eclipse\workspace\MVN\3cx-driver\src
java com.software._3cx.main.PBXConnection

Answer 3

Execute javac as below, this would compile the class file and place it in a directory structure as per the package structure.

javac -d PBXConnection.java

Then execute it using the below command,

java -cp . com.software._3cx.main.PBXConnection

This sets the current directory as your class path and then java will be able to find the class file as per the directory structure created in the previous step.