Java 我如何创建自己的通过点运算符调用的方法

Question

For example we have.toString() but we don't have.toStringAndTrim() or.toStringAndReplace(). So I want to create my own methods inside a library and when I import this library I want to access after dot operator. How can I do this in java? Is this possible?

Answer 1

Java how can i create my own methods which are calling via dot operator

You can't add methods to existing classes, except for those for which you can change the source. Java doesn't provide such a mechanism; other languages such as Kotlin do.

All you can do is to define a method which takes the "receiver" as the first parameter, eg

static String toStringAndTrim(Object receiver) {
  return receiver.toString().trim();
}

and then invoke it like:

toStringAndTrim(thing)

You may want to be able to write this as thing.toStringAndTrim() , but it's just not possible in Java.