ClassLoader类的getPackage()方法 (ClassLoader Class getPackage() method)

• getPackage() method is available in java.lang package.

  getPackage()方法在java.lang包中可用。

• getPackage() method is used to return the package that has been defined in ClassLoader or the Package has been defined in ClassLoader ancestors.

  getPackage()方法用于返回在ClassLoader中定义的包或在ClassLoader祖先中定义的包。

• getPackage() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  getPackage()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。

• getPackage() method does not throw an exception at the time of returning an object of Package type.

  返回Package类型的对象时， getPackage()方法不会引发异常。

Syntax:

句法：

    protected Package getPackage(String pack_name);

Parameter(s):

参数：

• String pack_name – represents the name of the Package.

  字符串pack_name –表示软件包的名称。

Return value:

返回值：

The return type of this method is Package, it returns the following values based on the given cases,

此方法的返回类型为Package ，它根据给定的情况返回以下值：

• It returns the Package of the class which is loaded by the class loader of this Class.

  它返回由该类的类加载器加载的类的Package。

• It returns null, when no package is loaded by the class loader of this Class.

  当此Class的类加载器未加载任何包时，它返回null。

Example:

例：

// Java program to demonstrate the example 
// of Package getPackage(String pack_name) method of 
// ClassLoader
public class GetPackageOfClass extends ClassLoader {
void getPackage() throws ClassNotFoundException {
// It return the package
Package pack = super.getPackage("java.lang");
// Display Package Name
System.out.print("Package Name: ");
System.out.println(pack);
}
public static void main(String[] args) throws Exception {
GetPackageOfClass cp = new GetPackageOfClass();
cp.getPackage();
}
}

Output

输出量

Package Name: package java.lang

翻译自: https://www.includehelp.com/java/classloader-getpackage-method-with-example.aspx