java compiler_Java Compiler command（）方法与示例

拼搏现实的明天。 2023-03-05 15:52 9阅读 0赞

java compiler

## 编译器类command()方法 **(**Compiler Class command() method**)** ##

*  **command() method** is available in java.lang package.
    
    **command()方法**在java.lang包中可用。
 *  **command() method** is used to check the argument type and its fields and perform operations related to the command line.
    
    **command()方法**用于检查参数类型及其字段，并执行与命令行相关的操作。
 *  **command() method** is a static method, it is accessible with the class name and if we try to access the method with the class object then we will not get any error.
    
    **command()方法**是一个静态方法，可以通过类名进行访问，如果尝试使用类对象访问该方法，则不会出现任何错误。
 *  **command() method** may throw an exception at the time of performing command-line operations.
    
    在执行命令行操作时， **command()方法**可能会引发异常。
    
    **NullPointerException**: This exception may throw when the given Object parameter is null exists.
    
    **NullPointerException** ：当给定的Object参数为null时，可能引发此异常。

**Syntax:**

**句法：**

public static Object command(Object ob);

**Parameter(s):**

**参数：**

*  Object ob – represents compiler defined parameter.
    
    对象ob –表示编译器定义的参数。

**Return value:**

**返回值：**

The return type of this method is Object, it returns compiler–defined value and it includes null value.

该方法的返回类型为Object ，它返回编译器定义的值，并且包含空值。

**Example:**

**例：**

// Java program to demonstrate the example 
    // of Object command(Object ob) method of Compiler 
    
    public class Parent {
        
        public static void main(String args[]) {
        
            // Creating a Parent and Child class object
            Parent p1 = new Parent();
            Parent p2 = new Child();
    
            // By using getClass() method is to get a Parent class
            Class cl1 = p1.getClass();
            System.out.println("p1.getClass() = " + cl1);
    
            // By using getClass() method is to get a Child class
            Class cl2 = p2.getClass();
            System.out.println("p2.getClass() = " + cl2);
    
            //By using command(Object ob) method to compile Child //class
            Object ob = Compiler.command("javac Child");
            System.out.println("ob = " + ob);
        }
    }
    
    class Child extends Parent {
        
        public void show() {
        
            System.out.println("We are in Child class: ");
        }
    }

**Output**

**输出量**

p1.getClass() = class Parent
    p2.getClass() = class Child
    ob = null

> 翻译自: [https://www.includehelp.com/java/compiler-command-method-with-example.aspx][https_www.includehelp.com_java_compiler-command-method-with-example.aspx]

java compiler

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