ClassLoader类findLoadedClass()方法 (ClassLoader Class findLoadedClass() method)

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

  findLoadedClass()方法在java.lang包中可用。

• findLoadedClass() method is used to return the Class with the given binary class name when this loader has been recorded by JVM as initializing the loader of the class with that binary name.

  当JVM在使用该二进制名称初始化类的加载器时记录了该加载器时，将使用findLoadedClass()方法返回具有给定二进制类名称的Class。

• findLoadedClass() 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.

  findLoadedClass()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。

• findLoadedClass() method may throw an exception at the time of loading Class object.

  在加载Class对象时， findLoadedClass()方法可能会引发异常。

Syntax:

句法：

    protected Class findLoadedClass(String class_name);

Parameter(s):

参数：

• String class_name – represents the binary name of the class.

  字符串class_name –表示类的二进制名称。

Return value:

返回值：

The return type of this method is Class, it returns Class object when the class has been recorded otherwise it returns null, when the class has not been recorded.

该方法的返回类型为Class ，当记录了该类时，它将返回Class对象；否则，当未记录该类时，它将返回null。

Example:

例：

// Java program to demonstrate the example
// of Class findLoadedClass(String class_name)
// method of ClassLoader
class FindLoadedClass extends ClassLoader {void loadedClass() {// It checks whether the given class is loaded
// or not by using the findLoadedClass()
Class cl1 = super.findLoadedClass("java.lang.String");
// If cl1 not null that means cl1 is loaded
// then don't need to load again
if (cl1 != null)
System.out.println(" Class already loaded!!!");
else
System.out.println("Ready to load the given class by using loadClass()!!!");
}
}
public class Main {public static void main(String[] args) throws Exception {// Creating an instance of FindLoadedClass
FindLoadedClass lc = new FindLoadedClass();
lc.loadedClass();
}
}

Output

输出量

Ready to load the given class by using loadClass()!!!

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