one-to-one, one-to-many, manty-to-one and many-to-many of JPA relational mappings

Spring Data JPA is a sub-project of Spring Data. By providing JPA-based Repository, it greatly reduces the amount of code JPA is used as a data access scheme. You only need to write an interface defined within Spring Data JPA under interface integration to complete simple CRUD operations. Preface This article guides you through Spring Boot, S ...

Posted by romanali on Fri, 14 Dec 2018 08:48:03 -0800

Flying-saucer + iText + Freemarker implements pdf export, supports Chinese, css and pictures

Preface There is a requirement in the project to export the contract content to pdf. IText is an open source Java library for generating PDF documents. It can dynamically generate PDF from XML or database. It can also encrypt documents, control privileges, and support Java/C# etc. But the HTML parser provided by iText itself is not strong enoug ...

Posted by hussainz2000 on Thu, 13 Dec 2018 23:12:06 -0800

Servlet JSP Tutorial -- 1.14 Async Servlet Example

Asynchronous servlet is introduced in Servlet 3. This is a good way to deal with thread starvation when running threads for long periods of time. Async Servlet Before we understand what an asynchronous Servlet is, let's try to understand why we need it. Suppose we have a Servlet that takes a lot of time, like the fol ...

Posted by heavenly on Thu, 13 Dec 2018 15:42:05 -0800

ASP.NET MVC logs using Log4net

Log4net introduction Log4net, Apache's next open source project, is a clone of Log4j. We can control the destination of log information output. Log4net defines a variety of log information output modes. It can output logs to console, text files, windows log event viewer, including database, mail and other locations, so that we can quickly trac ...

Posted by kgahn on Tue, 11 Dec 2018 03:42:05 -0800

Struts 2 - > validate and interceptor

1.Validate 1.1 Rewriting validate Method For example, do the login page on the front desk action: 1.2 checkout framework 1. Write a checking rule file It is a typical XML file in the format of ActionName-validation.xml The validation file needs to add a dtd constraint description The dtd description is in xwork-core <!DOCTYPE va ...

Posted by KGodwin on Mon, 10 Dec 2018 10:09:06 -0800

Use and Analysis of [Curator] Persistent Ephemeral Node/Persistent Node

Persistent Ephemeral Node / Persistent Node A persistent node that can be maintained when a link or session is interrupted. 1. key API org.apache.curator.framework.recipes.nodes.PersistentEphemeralNode 2. mechanism description Actually, it's org.apache.curator.framework.recipes.nodes.PersistentNode. Considering a lot of abnormal situations, it ...

Posted by Reef on Mon, 10 Dec 2018 09:21:05 -0800