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1. For the 1-1 association based on foreign key, the foreign key can be stored on either side, and the many to one element can be added at the end where the foreign key needs to be stored. Add unique = "true" attribute to many to one element to represent 1-1 Association 2. The other end needs to use the one-to-one ...

The basic knowledge points are as follows: Introduce annotation constraints and configure component scanning Annotation on class: @ response @ Controller @Service @Repository Annotation @ value of common attribute Annotation @ Resource @ Autowired @ Qualifier for object properties Bean life cycle, initialization and destruction: @ PostConstruc ...

This article mainly describes how to verify form information in springboot. In the spring MVC project, the form information needs to be checked, and the form information verification is mainly in the form of annotation. Construction project To create a springboot project, because web, thymeleaf, validator and el are used, corresponding start ...

* ps : I. retrieval method of navigation object graph Customer c=session.get(Customer.class,2); c.getOrders().size(); Through mapping in Hibernate, the associated persistent object information can be obtained by navigation during hibernate operation. II. OID search method session.get(Customer.class,3); session.load(Order.class,1); In H ...

Recently, druid monitoring is needed for maintenance of old projects, but druid is at least compatible with hibernate 4. There is no way to do this. You can do it by yourself. Based on com.alibaba.druid.support.hibernate.DruidConnectionProvider, the ConnectionProvider interface is implemented To use the druid data source, make the following c ...

Shared memory for nginx is one of the main reasons it can achieve high performance, mainly for file caching.This article first explains how shared memory is used, then how nginx manages shared memory. 1. Use examples nginx declares that the instructions for shared memory are: proxy_cache_path /Users/Mike/nginx-cache levels=1:2 keys_zone=one:10m ...

How to get the type of generic T, that is, T.class I want to write a mongodb tool class in spring boot, and simply encapsulate some of mongodb's entries. In the process of writing the tool class, I found that many of the mongodb methods integrated in spring boot need to use entity class types. In the tool class, I use generi ...

Introduction When it comes to the word "persistence", people who operate databases every day are certainly familiar with it. In persistence, the two giants that have caught the attention of developers are Hibernate and MyBatis, and many developers often compare them.Google is a comparison of the two. Hibernate and MyBatis, like java ...

0.jar package depends on maven pom.xml 　　<properties> <spring_version>4.3.25.RELEASE</spring_version> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> ...

When browsing Stack Overflow, I found that the most popular problem is: what is NullPointerException (java.lang.NullPointerException), what causes it, and whether there is a good way or tool to track the cause of it? I didn't expect to see as many as 2.5 million views of this problem! So, I think it's time to sort out the best answers and share ...