Null pointer problem in batch operations such as saveBatch in mybatis-plus describe: Error message Solutions solution doubt Reference blog Description: It’s almost time to get off work again, haha. I hope I can help you. I’ll explain it in a scribble. Null pointers will appear in batch operations, but there is no problem in a […]
Tag: nullpointerexception
Solved Java Error: Exception in thread main java.lang.NullPointerException BUG》
Blogger Maotouhu () takes you to Go to New World? Blog homepage: Maotouhu’s blog “Complete Column of Interview Questions” Articles with pictures and texts Vivid images Simple and easy to learn! Everyone is welcome to step in~ “IDEA Development Cheats Column” Learn the common operations of IDEA and double your work efficiency~ “Master Golang in […]
Java elegantly removes NullPointerException null pointer exception
Solution: Optional class provided by JDK Introduction to related APIs (not all, these four functions are related) First group Optional(T value),empty(),of(T value),ofNullable(T value) Let me first explain, Optional(T value), that is, the constructor, it has private permissions and cannot be called externally. The remaining three functions are public permissions for us to call. The essence […]
Get rid of the annoying NullPointerException. This is elegant!
At the beginning of the article, let’s talk about the NPE problem first. The NPE problem is the NullPointerException we often encounter in development. Suppose we have two classes, and their UML class diagrams are as shown below In this case, there is the following code user.getAddress().getProvince(); This way of writing may cause a NullPointerException […]
When the java project is running, a null pointer exception appears in the backend console—java.lang.NullPointerException
Project scenario: Tip: Here is a brief description of the project background: The scene is as follows: When the java project is running, the backend console displays an error message as shown in the figure below: – Description of the problem Hint: Here is a description of the problems encountered in the project: When the […]
Java’s elegant handling of NullPointerException null pointer exception
Foreword The NPE problem is the NullPointerException that we often encounter in development. Suppose we have two classes, and their UML class diagram is shown in the figure below In this case, there is code like user.getAddress().getProvince(); This way of writing, when the user is null, it is possible to report a NullPointerException exception. In […]
Get rid of NullPointerException, so write elegantly!
Source: blog.csdn.net/zjhred/article/details/84976734 At the beginning of the article, let’s talk about the NPE problem. The NPE problem is the NullPointerException that we often encounter in development. Suppose we have two classes, and their UML class diagram is shown in the figure below In this case, the following code: user.getAddress().getProvince(); This way of writing, when the […]
Get rid of the annoying NullPointerException null pointer exception, so elegant!
A Programmer’s Path to Growth Internet/Programmer/Technology/Data Sharing focus on It will take about 6 minutes to read this article. From: blog.csdn.net/zjhred/article/details/84976734 At the beginning of the article, let’s talk about the NPE problem first. The NPE problem is the NullPointerException that we often encounter in development. Suppose we have two classes, and their UML class […]
Dive into NullPointerException in Java
1. Introduction 1.1 introduces the definition and common causes of NullPointerException NullPointerException is a runtime exception in Java, which is usually thrown when a null pointer reference occurs in the program. When we try to perform a method call, property access, or array operation on a null object, a NullPointerException will be triggered. This is […]
Get rid of the annoying NullPointerException null pointer exception, so elegant!
At the beginning of the article, let’s talk about the NPE problem first. The NPE problem is the NullPointerException that we often encounter in development. Suppose we have two classes, and their UML class diagram is shown in the figure below In this case, there is the following code user.getAddress().getProvince(); This way of writing, when […]