Class.newInstance 调用无参数构造函数(不带任何参数的构造函数).为了调用不同的构造函数，您需要使用反射包(java.lang.reflect).

Class.newInstance invokes the no-arg constructor (the one that doesn't take any parameters). In order to invoke a different constructor, you need to use the reflection package (java.lang.reflect).

像这样获取一个 Constructor 实例:

Get a Constructor instance like this:

Class<?> cl = Class.forName("javax.swing.JLabel");
Constructor<?> cons = cl.getConstructor(String.class);

对 getConstructor 的调用指定您需要采用单个 String 参数的构造函数.现在创建一个实例:

The call to getConstructor specifies that you want the constructor that takes a single String parameter. Now to create an instance:

Object o = cons.newInstance("JLabel");

大功告成.

附言仅将反射作为最后的手段！

P.S. Only use reflection as a last resort!