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In java, object references are divided into strong, soft, if and virtual references. Strong references are ordinary new objects. Soft references, weak references and virtual references are all inherited from the abstract class Reference. 1. Strong reference The most common references in program code, such as person period = new person(), ...

1. Strong References (Objects) Features: Strong references provide direct access to the target object. Will not be recycled. Two, soft reference (SoftReference class) Features: When GC reclaims based on JVM memory, JVM reclaims when it finds it is out of memory Conditions for freeing up space: JVM found insufficient m ...

First of all, there is no single pattern of hungry Han, lazy, if you need Baidu A little better than the Hungry Han style is the static inner class singleton Paste code here package com.test; public class SimpleTest { private static class SimpleNB { private static final SimpleTest INSTANCE = new SimpleTest(); } private SimpleT ...

Call of kotlin data class Call of object simple profit mode class in Kotlin Calling file class in Kotlin Flexible transfer of parameters by calling jvm annotation String string null call Call of kotlin data class kotlin Code: package com.tianfu.kotlin /** * age Member annotations cannot have get and ...

java packing and unpacking Packing Unpacking Do an experiment Packing Basic data type = > wrapper class For example, int = > integer Unpacking Wrapper class = > basic data type For example, integer = > int Why are there basic data types? Because in java, a new object is stored in t ...

This is a question for my recent interview There are several ways to create a single example of the interviewer's question. I answered the lazy man and the hungry man. He told me that there are two kinds. In fact, I still vaguely remember two kinds. I just can't remember, and my heart silently tears.... ...

Define annotation syntax @Target({ElementType.METHOD}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface MyAnnotation { String className() default ""; String methodName(); } @Target annotation description @Target is the location restriction for annotation, and the ...

Deep understanding of synchronized underlying source code preface This article analyzes the implementation logic of synchronized from the JVM source code, so as to better understand the depth of synchronized. Process: the basic unit of operating system resource allocation. Thread: the basic unit of ...

In "deep understanding of Java virtual machine: advanced features and best practices of JVM (version 2)", the working process of CMS collector is introduced as follows: CMS collector is based on the "mark clear" algorithm. Its operation process is more complex than the previous coll ...

Design pattern 1, Singleton mode characteristic: A singleton class can only have one instance A singleton class must create its own unique instance Singleton classes must provide this instance to all other objects solve the problem: A global class is frequently created and destroyed   1. Lazy mode public class Singl ...