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1, If Else… val x = 5 val s = if (x > 0) 1 else -1 // s type is Int val m = if (x > 0) "positive" else -1 // Public super type Any with s type String and Int // In Scala, each expression should have a value. If the else part is missing, the following statement is equivalent to: if (x > 0) 1 else(), which returns a null ...

Catalog annotation Built in annotations Meta annotation Custom annotation Reflection mechanism brief introduction Class Class Java memory Class loading process ClassLoader Reflection gets the structure information of the runtime class Creating objects dynamically Create objects by reflection (general) Create an object with constructor ob ...

GitHub We define the roles of the main classes: Spring classloader: when this class is set as the default classloader of the main thread, all subsequent classes will be loaded, and class loading scheduling will be performed (if the parent classloader is not loaded into this class, it will be handed over to ServiceClassLoader for loading) S ...

There are a lot of articles on the Internet saying solutions, but they don't analyze the reasons. The solution is idea settings Add - Dfile.encoding=GBK or GB2312 to VM Options, so the garbled code will be the correct Chinese character, BUT!!!, why? Cause analysis -How does idea interact with maven C:\Java\jdk1.8.0_162\bin\java.exe -Dmaven.mult ...

Summary (1) Object class(two) class Date(3) Calendar Class(4) System class(5) StringBuilder class(6) Basic type packaging (1) Object class demo01: Summary The java.lang.Object class is the root class in the Java language, that is, the parent class of all classes. All method subclasses describ ...

When you write Java code, repetitive operations are often involved, so it's good to think of a plug-in like this. If it's a scenario everyone will encounter, the IDE may have already provided it, or someone else may have written it.If this is unique to your coding environment, you will have to write your own tools.So here's how to write IDEA pl ...

What is serialization and deserialization? Serialization: converting objects into streams, saving them to disk, or transferring them to the network. Deserialization: that is, to invert this stream back to the object. So what's the use of serialization? 1) Permanently save objects on disk 2) Serializat ...

Welcome to spring cloud. In this chapter, we will teach you how to create the parent-child project architecture of spring cloud. Knowledge is endless, and stories are good or bad. Articles are purely fictional. Welcome to Tucao. How can I walk in the Jianghu without any tricks. The technologies and tool ...

Article directory 1, Environmental preparation 1. Install JUnitGenerator 2. Add JUnit.jar package to the project 2, Write test code 1. Write test class in src directory 2. Write a test class in the test directory (if not, create a new test and set it to Test Resources Root) 3. Create a new Test ru ...

Change from: https://blog.csdn.net/wangyuanjun008/article/details/79233491 Method: crack patch activation method (1) Download the crack patch Click me to download (password jilt) Put the downloaded crack patch under the bin directory under your installation IDEA (as shown in the figure). The example of this article is e: \ ...