【Java面试】反射中，Class.forName和classloader的区别是什么？

//Class.forName(String className) 这是1.8的源码
public static Class<?> forName(String className) throws
ClassNotFoundException {
Class<?> caller = Reflection.getCallerClass();
return forName0(className, true, ClassLoader.getClassLoader(caller),
caller);
}
//注意第二个参数，是指Class被loading后是不是必须被初始化。 
//不初始化就是不执行static的代码即静态代码

package com.lxk.Reflect;
/**
* Created by lxk on 2017/2/21
*/
public class Line {
static {
System.out.println("静态代码块执行：loading line");
}
}
package com.lxk.Reflect;
/**
* Created by lxk on 2017/2/21
*/
public class Point {
static {
System.out.println("静态代码块执行：loading point");
}
}
package com.lxk.Reflect;
/**
* Class.forName和classloader的区别
* <p>
* Created by lxk on 2017/2/21
*/
public class ClassloaderAndForNameTest {
public static void main(String[] args) {
String wholeNameLine = "com.lxk.Reflect.Line";
String wholeNamePoint = "com.lxk.Reflect.Point";
System.out.println("下面是测试Classloader的效果");
testClassloader(wholeNameLine, wholeNamePoint);
System.out.println("----------------------------------");
System.out.println("下面是测试Class.forName的效果");
testForName(wholeNameLine, wholeNamePoint);
}
/**
* classloader
*/
private static void testClassloader(String wholeNameLine, String
wholeNamePoint) {
Class<?> line;
Class<?> point;
ClassLoader loader = ClassLoader.getSystemClassLoader();
try {
line = loader.loadClass(wholeNameLine);
point = loader.loadClass(wholeNamePoint);
//demo =
ClassloaderAndForNameTest.class.getClassLoader().loadClass(wholeNamePoint);//这个
也是可以的
System.out.println("line " + line.getName());
System.out.println("point " + point.getName());
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
/**
* Class.forName
*/
private static void testForName(String wholeNameLine, String wholeNamePoint)
{
try {
Class line = Class.forName(wholeNameLine);
Class point = Class.forName(wholeNamePoint);
System.out.println("line " + line.getName());
System.out.println("point " + point.getName());
} catch (Exception e) {
e.printStackTrace();
}
}
}