Run a Java Class with Command-Line

I have 4 Java-Data:

Common.java
Constants.java
KeywordsEditor.java
ExecutionEngine.java (There is here a Main-Method) 

I have successful compiled in Command-Line with this Command from Project-Directory (C:\ProjectDemo\src\main\java\ValueInput)

javac -cp "C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.j‌​ar" *.java 

I got 4 Data .class in the same Directory. Now i want to run them with this code:

java -cp "C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.j‌​ar" ExecutionEngine 

But i got Error:

Error: ExecutionEngine main class could not be found or loaded 

``` 
I've tried with some same code else:
```
java -cp "C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;libs\*;selenium-server-standalone-3.141.59.j‌​ar" ExecutionEngine 

java -cp "C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;libs/*;selenium-server-standalone-3.141.59.j‌​ar" ExecutionEngine 
```

And some more, but they don't work. Can somebody help me?


</details>


# 答案1
**得分**: 1

# 更新

从您的评论中，我了解到在 `ExecutionEngine.java` 中提到了 `package ValueInput;`。因此，在编译时，您应该使用 `-d` 开关：

```shell
javac -d . -cp "C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.jar" *.java
```

选项 `-d .` 要求编译器将生成的类文件放置在当前目录中。现在，如果您在Mac/Unix中使用 `ls` 命令或在Windows中使用 `dir` 命令，您将看到一个名为 `ValueInput` 的目录已经创建，并且所有的 `.class` 文件已放置在此目录中。通过简单地使用 `javac` 命令来了解更多关于这些开关的信息。

为了执行 `ExecutionEngine.class`，您可以使用以下命令：

```shell
java -cp ".;C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.jar" ValueInput.ExecutionEngine
```

您还可以查看[此答案](https://stackoverflow.com/a/63319381/10819573)以获取类似的解决方案。

**附注：** 您应该遵循[Java命名约定](https://www.oracle.com/java/technologies/javase/codeconventions-namingconventions.html)。根据约定，包的名称应该类似于 `value.input`。

# 原始答案

问题的根本原因是只使用了 `-cp` 来添加JAR文件。您可能没有意识到您的 `ExecutionEngine.class` 不在JAR文件中；而是在当前目录中，由点号 (`.`) 表示，您忘记将其包含在类路径中。

因此，正确的命令应该是：

```shell
java -cp ".;C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.jar" ExecutionEngine
```

无论您将 `.` 即当前目录放在何处，以下命令也将适用：

```shell
java -cp "C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.jar;." ExecutionEngine
```

**Mac提示：**

在Mac中用于此目的的分隔符是 `:` 而不是 `;`，例如：

```shell
javac -cp mysql-connector-java-5.1.49.jar MysqlDemo.java
java -cp mysql-connector-java-5.1.49.jar:. MysqlDemo
```

**Java-11及以后版本提示：**
[Java-11允许启动单文件源代码程序][1]而无需编译，例如：

```shell
java -cp mysql-connector-java-5.1.49.jar MysqlDemo.java
```

您可以从[这篇文章](https://www.infoq.com/articles/single-file-execution-java11/)了解更多信息。

  [1]: https://openjdk.java.net/jeps/330

<details>
<summary>英文:</summary>

# Update

From your comment, I learnt that you have `package ValueInput;` mentioned in `ExecutionEngine.java`. Therefore, you should use the switch `-d` when compiling:

    javac -d . -cp &quot;C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.j‌​ar&quot; *.java

The option `-d .` asks the compiler to place the generated class files at the current directory. Now, if you use the command `ls` in Mac/Unix or `dir` in Windows, you will see a directory, `ValueInput` has been created and all the `.class` files have been placed inside this directory. Learn more about the switches by simply using the command `javac` 

In order to execute `ExecutionEngine.class`, you can now use the following command:

    java -cp &quot;.;C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.j‌​ar&quot; ValueInput.ExecutionEngine 

You can also check [this answer](https://stackoverflow.com/a/63319381/10819573) for a similar solution.

**Side note:** You should follow the [Java naming conventions](https://www.oracle.com/java/technologies/javase/codeconventions-namingconventions.html). As per the convention, the name of the package should be something like `value.input`.


# Original answer

The root cause of the problem is using only jars with `-cp`. You missed realizing that your `ExecutionEngine.class` is not in the jars; rather it is at the current directory which is denoted by a dot (`.`) which you missed to include in the classpath.

Thus, the correct command will be:

    java -cp &quot;.;C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.j‌​ar&quot; ExecutionEngine 

It doesn&#39;t matter where you put `.` i.e. the current directory e.g. the following will also work for you:

    java -cp &quot;C:\Users\ABC\selenium-java-2.48.2\selenium-2.48.2\selenium-java-2.48.2.jar;selenium-server-standalone-3.141.59.j‌​ar;.&quot; ExecutionEngine 

**Note for Mac:**

The separator used for this purpose in Mac is `:` instead of `;` e.g.

    javac -cp mysql-connector-java-5.1.49.jar MysqlDemo.java
    java -cp mysql-connector-java-5.1.49.jar:. MysqlDemo

**Note for Java-11 onwards:**
[Java-11 allows launching Single-File Source-Code programs][1] without compiling e.g.

    java -cp mysql-connector-java-5.1.49.jar MysqlDemo.java

You can learn more about it from [this article](https://www.infoq.com/articles/single-file-execution-java11/).

  [1]: https://openjdk.java.net/jeps/330

</details>