Programmer Group

1, What is this keyword this is a keyword in java; This can be a reference or a variable in java. When it is a variable, the memory address saved in the variable points to itself, and this is stored in the JVM heap memory java object   2, What is the function of this keyword 1. The first function of this keyword is to pass the value of the loc ...

Synchronization mechanism 1, Synchronization block When multiple threads operate on the same data, data errors and data insecurity are caused.   Solution: when multiple threads operate on the same data, only one thread can operate on the data at a time The synchronization block syntax used in Java is as follows: synchronized(obj) {/ / ...

Use of wrapper Gradle Wrapper is the recommended usage of gradle. This article will illustrate how to use it with specific examples. Gradle Wrapper The Gradle Wrapper is actually a script, which can be used to download and use the specified version of gradle. It can be downloaded before use as required, effectively avoiding environment consiste ...

1. Lock API 1. Locks package class hierarchy 2. Lock interface Method Signature describe void lock(); Acquire locks (endless) boolean tryLock(); Acquire locks (just try it) boolean tryLock(long time, TimeUnit unit) throws InterruptedException; Acquire locks (out of date) void lockInterruptibly() throws InterruptedException; Acquire ...

1, What is jconsole jconsole is the built-in Java performance analyzer of jdk, which is used to monitor the performance of Java applications and track the code in Java; It has a close relative, that is, JVM; 2, How to use 1. It's very simple. On the command line of idea, enter: D:\java\workspace\AS> jconsole The GUI: Here is a dead ...

1, The concept of multithreading 1. Process: every program being executed is called a process. Process is an independent unit of resource allocation and call. Each process has its own memory space and system resources. 2. Thread: a thread is an execution path of a process. A process with only one execution path is call ...

1, Exception overview and exception architecture 1. Overview of exceptions In the process of using computer language for project development, even if the programmer writes the code perfectly, there are still some problems in the operation of the system, because many problems can not be avoided by the code, such as: the format of customer input ...

SpringCloud Chapter VIII, Upgrade, Load Balancing and Service Calls Ribbon and OpenFeign 1. Ribbon 1. Overview SpringCloud Ribbon is a set of client load balancing tools that give NetFlex Ribbon implementations. Simply put, the main function is to provide load balancing algorithms and service calls for clients.The Ribbon client componen ...

What is a classloader: public class ClassInit { public static void main(String[] args) { ClassLoader c=ClassInit.class.getClassLoader(); } } The ClassLoader above is the ClassLoader Print c, and notice a Launcher class: sun.misc.Launcher$AppClassLoader@18b4aac2   Enter the Launcher class and notice two pieces of code: var1 ...

jvm settings http://www.360doc.com/content/12/1023/16/9615799_243296263.shtml Heap setup -Xms: initial heap size -Xmx: maximum heap size -20: Newsize = n: set younger generation size -20: Newratio = n: set the ratio of young generation to old generation. For example, if it is 3, it means that t ...