String, file, stream MD5 encryption

Article catalog MD5 introduction use MD5 introduction MD5 message digest algorithm * * (English: MD5 message digest algorithm), a widely used cryptographic hash function, can generate a 128 bit (16 byte) hash value to ensure the integrity and consistency of information transmission. MD5 was designed by Ronald Lin Rives ...

Posted by Madzz on Thu, 21 May 2020 07:47:29 -0700

Spring MVC advanced - how to use interceptors correctly? Case explanation

Spring MVC: interceptor Implemented the HandlerInterceptor interface. Function: used to intercept the controller   2, Define an interceptor 1. Environment construction @Component public class Demo1Interceptor implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, ...

Posted by emma57573 on Wed, 20 May 2020 23:03:42 -0700

JS performs Base64 encoding, MD5 encryption and URL encoding to realize the signature verification of express bird API interface

Some netizens left a message saying that they wanted to call the express bird API interface to realize Express query, but they didn't understand the back-end development, JAVA, PHP, C and python. They asked me if I could realize express interface query, and I said what would you do, he said, I only know a little bit about JS. I replied that it ...

Posted by ATLien on Wed, 20 May 2020 08:15:41 -0700

Spring Boot Tutorial - HelloWorld

1. Origin of Spring Boot As we all know, the Spring Framework is a very important and lightweight framework in the Java ecology, helping our broad masses of big guys develop Java.The Spring Framework has evolved very rapidly, from the very beginning of the Spring core container that helped us manage Java objects to the various business issues t ...

Posted by frostyhorse on Tue, 19 May 2020 09:50:29 -0700

Build your first blockchain network

Previous article: Build your first blockchain network (3) UTXO component UTXO is an important concept in bitcoin. In this section, we will implement a simple UTXO. We divide the components of UTXO into the following three points: UTXOId: identify the UTXO TxInput: transaction input, i.e. input address and amount of coin TxOutput: ...

Posted by tomtimms on Tue, 19 May 2020 05:33:23 -0700

Java learning - JDK dynamic agent

proxy pattern What is agent mode? Agent mode is to find an intermediary to help you do something. You just need to pay attention to your own business, and other intermediaries will help you. There are three elements in the agent model: Abstract objects: Interfaces Proxy objects: classes Real objects: classes Static agent Static proxy: you can ...

Posted by illzz on Tue, 19 May 2020 03:26:35 -0700

Haven't you built and used Maven Nexus private library?

Why use private library By default, maven goes to the remote central warehouse to download the JAR package. It's quite slow to visit the foreign network. If everyone in the team downloads the JAR package once, it's undoubtedly a waste of the network. Of course, it can also add the domestic image, such as Ali's, which is relatively stable. But ...

Posted by DeadEvil on Tue, 19 May 2020 03:20:28 -0700

double cannot be used as a money operation

float and double can only be used for scientific calculation or engineering calculation. In business calculation, we need to use java.math.BigDecimal . I heard that a colleague said that a friend of his had been used by hackers because he used double to calculate money, resulting in a lot of losses. Let's talk about this. brief introduction ...

Posted by chrisredding on Tue, 19 May 2020 02:58:25 -0700

LeetCode 680. Verify palindrome string II

My LeetCode: https://leetcode-cn.com/u/ituring/ My LeetCode source code [GitHub]: https://github.com/izhoujie/Algorithmcii LeetCode 680. Verify palindrome string II subject Given a non empty string s, delete at most one character. Determine whether it can be a palindrome string. Example 1: Enter: "aba" Output: True Example 2: Enter ...

Posted by Ghostgator on Mon, 18 May 2020 23:55:33 -0700

[java framework] JPA -- JPA mapping relationship

1. One way one to many configuration One way one to many is configured with the @ OneToMany tag. One party has a Set attribute associated with multiple parties. A Set can be a List or a Set, but the difference is that a List is ordered and a Set is not repeated. Corresponding to the configuration of @ OneToMany on one side: /** * One way one ...

Posted by scott.stephan on Mon, 18 May 2020 10:53:00 -0700