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1, Classloader Loading overview of class 1.1 Class loading overview When a program wants to use a class, if the class has not yet been loaded into memory, The system will initialize this class in three steps: loading, connecting and initializing. Load It means to read the class file into memor ...

1, Application scenario of decorator mode In our life, for example, add an egg to a pancake, add some fruit to the cake, decorate the house, etc. Extend the responsibilities of some extra objects to objects. Decorator Pattern means that it provides a more flexible alternative (extending the function of the original object) than inheritance with ...

Introduction to Alpine Linux 1.Alpine Linux is a lightweight Linux distribution. It is different from the usual Linux distribution (centos, Ubuntu), Alpine uses musl libc and BusyBox reduces system size and runtime resource consumption. 2.Alpine Linux provides its own package management tool ...

I. overview Apache Maven is a software engineering management and integration tool. Based on the concept of project object model (POM), Maven is able to manage project construction, reporting and documentation through a central information management module. There are many advantages of building proje ...

/* Use of interface s 1. Define an interface using the format of interface interface name {}. The primary purpose of an interface is to be implemented by an implementation class.(interface-oriented programming) 2. Interfaces and classes are side-by-side structures in java. 3, Members inside the inte ...

Recommend a video resource of Gupao College: link: https://pan.baidu.com/s/1SmSzrmfgbm6XgKZO7utKWg Password: e54x First, I will answer the questions that students didn't add in the previous release "be careful when using HashMap". I'd better say how HashMap solves the problem of dead cycle in JDK8. The link list part corresponds to t ...

introduce jdk explained: public class FileInputStream extends InputStream A FileInputStream gets input bytes from files in the file system.What files are available depends on the host environment. FileInputStream is used to read raw byte streams such as image data.To read a string, consider using File ...

1, Introduction of containers and generics No matter what language it is, it is necessary to deal with data in the process of developing programs. In order to better accommodate these data, we introduced the concept of array in the previous study, which is indeed a good way to accommodate data, but ar ...

Let's talk about the last step of preparing to upgrade presto, because the pre deployed Presto machine itself deployed a CDH cluster (customer's home), and the machine was Centos6.x. according to the JDK on the Cloudrea official website, it can't move. Later, it was found that his JDK environment variab ...

Generalization The main serialization methods of redis are string serialization, json serialization, xml serialization, jdk serialization. The implementation classes of org.springframework.data.redis.serializer.RedisSerializer can be consulted. For json serialization, jackson serialization is the official implementation, and fastjson has corre ...