ABCL armed bear Common Lisp: Implement object -oriented programming skills in the Java class library

ABCL armed bear Common Lisp: Implement object -oriented programming skills in the Java class library Abstract: This article will introduce how to use ABCL for armed bear Common Lisp to achieve object -oriented programming skills, and combined with the Java class library to provide relevant code examples. introduction: ABCL armed bear COMmon Lisp is a powerful programming language, which combines the characteristics of Common Lisp and the Java ecosystem.When conducting object -oriented programming, the Java class library has rich resources and tools, and the ABCL armed bear COMMON LISP can provide us with more advanced abstraction and flexibility.This article will introduce how to make full use of the Java class library for object -oriented programming when using ABCL armed bear Common Lisp, and give some example code to help readers better understand. 1. Introduce the Java class library In the ABCL armed bear Common Lisp, we can expand its functions by introducing the Java class library.Through the Java class library, we can use rich Java tools and resources and combine it with the powerful characteristics of ABCL armed bear Common Lisp.The following is a sample code importing the Java library: lisp (import 'java.lang.Math) (import 'java.util.ArrayList) (import 'java.util.Date) 2. Create a Java object In ABCL armed bear Common Lisp, we can use Java syntax to create Java objects.The following example code shows how to create an ArrayList object and operate: lisp (let ((list (new 'ArrayList))) (dotimes (i 5) (list.add i))) (Print list); print results: [0, 1, 2, 3, 4] Third, the method and attribute of using the Java object We can use the Java syntax to call the Java object's method and access its attributes.Below is an example code that uses the Java Date object to obtain the current time: lisp (let ((date (new 'Date))) (print (.getTime date))) Fourth, inherit the Java class and implement interface ABCL armed bear COMMON LISP can also inherit the Java class and implement the Java interface.The following example code shows an example of inheriting the Java class: lisp (defclass Example extends java.util.ArrayList () ((length :initform 0 :accessor length) (items :initform (list) :accessor items))) (defmethod add ((this Example) item) (incf (length this)) (push item (items this))) (defun create-example () (let ((example (new 'Example))) (add example "Item 1") (add example "Item 2") (add example "Item 3") example)) 5. Java abnormal processing When using the ABCL armed bear Common Lisp, we can use Java's abnormal processing mechanism to deal with the abnormalities in the Java class library.Below is an example code that captures the abnormal Java: lisp (catch 'java-exception (with-java-exceptions ((ex 'Exception) (Print "capture Java abnormalities:" ex))) (java-method-throw-exception)) in conclusion: In this article, we introduced how to use ABCL for armed bear Common Lisp to achieve object -oriented programming skills in the Java library.We can use the powerful characteristics of ABCL armed bear Common Lisp and the rich resources of the Java class library to improve development efficiency.By importing the Java class library, creating Java objects, methods and attributes using Java objects, inheriting the Java class and implementing interfaces, and handling Java abnormalities, we can perform more flexible and efficient object -oriented programming.It is hoped that this article can help readers better understand and apply an object -oriented programming techniques of ABCL armed bear COMMON LISP in the Java library.