Programmer Group

1, Overview 1. The user-defined ClassLoader must inherit ClassLoader 2. loadClass method and findClass method The findClass() method is generally overridden, which loads the class into the jvm itself. The loadClass() method does not need to be overridden. It is a complete process of calling the parent delegation mechanism. 3. defineClass ...

1, Overview 1. The user-defined ClassLoader must inherit ClassLoader 2. loadClass method and findClass method The findClass() method is generally overridden, which loads the class into the jvm itself. The loadClass() method does not need to be overridden. It is a complete process of calling the parent delegation mechanism. 3. defineClass ...

Continue with synchronized, last article What's the difference between having synchronized or not? We have learned that synchronized is used when multiple threads compete for the same resource concurrently. In this article, we will learn what is locked by synchronized as a pessimistic lock? Lock instance object In the last article, we have cod ...

This paper mainly introduces the influence of automatic unpacking and boxing on the performance of operation from the perspective of bytecode and memory occupation. If you want to understand bytecode, you need to understand the structure of JVM virtual machine stack and code execution process. Please refer to "deep understanding of Java vi ...

Max HTTP header size settings server.max-http-header-size=999999999 //953m JVM parameter configuration -Xms800m -Xmx800m Write a rest api @RestController("action") public class HttpHandler { @PostMapping("/get") public String get() { return "get"; } } post access   Server OOM java.lang.OutOfMemoryError: Java heap spa ...

ClassLoader: A class loader responsible for loading a Class into the JVM and resolving the Class byte code into an object format that is universally required by the JVM.The entire life cycle consists of seven phases: loading, validating, preparing, parsing, initializing, using, and unloading. 1. How to load the class file 1.1, Loading G ...

Nowadays, programming languages are becoming more and more complex. Despite a large number of documents and books, these learning materials can only describe the tip of the iceberg of programming languages. Many of the functions in these programming languages may be hidden in the dark forever. This article will explain the secrets hidden in fi ...

Initially, I used this method of testing a million for loops public class Main { public static void main(String[] args) { long start = System.currentTimeMillis(); for (int j = 0; j < 1000000; j++){ } long stop = System.currentTimeMillis(); System.out.println(stop - start); } } ...

order This paper focuses on the Prometheus service of canal CanalMetricsService canal-1.1.4/server/src/main/java/com/alibaba/otter/canal/spi/CanalMetricsService.java public interface CanalMetricsService { /** * Initialization on canal server startup. */ void initialize(); /** * Clean-up at canal server stop phase. ...

Find thread PID 1. Use the top command to find the PID of the java process. The PID I found here is 13520 Locating thread After finding the process, locate the specific thread or code. First, display the list of threads, and sort them according to the threads with high CPU consumption: ps -mp 13017 -o THREAD,tid,time | sort -rn root># ps -m ...