JDK14, from its inception to now, its internal updates, really brought a lot of surprise to people, especially programmers, JDK14 is really attracted to this group of programmers to explore its mysterious color, from the very first five new features

JDK13:5 new features:

350: Dynamic CDS Archives

351: ZGC: Uncommit Unused Memory

353: Reimplement the Legacy Socket API

354: Switch Expressions (Preview)

355: Text Blocks (Preview)

Chinese Academy of Sciences engineers prepared for a month, and finally finished the JDK13 new feature ZGC

Today is idle, when chatting with friends, suddenly mentioned JDK14, and then went to look at the relevant documents, but also really let me find a more interesting technology -record, next, through the code to explore JDK14 record

Use the form

In fact, if you look at the code, it’s one line

Record Image(@serializedName ("media_id") String mediaId){} Image.mediaid ();Copy the code

So I’ve defined a record, an Image, and I’ve got a String mediaId in it and it looks something like this

Static class ImageClass{// Define a property private String mediaId; Public ImageClass(String mediaId) {this.mediaId = mediaId; } // define a get method public String getMediaId() {return mediaId; }}Copy the code

But now!! Now it’s just one line!! Really is the feeling of regret!!

Do wechat public number development partners should have this experience, so many nested entity classes. We’ll soon have hundreds of lines in a file. If the manager agrees, try record in JDK14

(By the way, we don’t even have JDK11 yet, do you?)

Run the configure

Since this feature is still in preview, it will require some additional configuration to work

idea

Idea need to download the 2020.1 RC version, and then select the language level 14-Preview in the project Settings, as shown in the figure below

gradle

Gradle needs to upgrade to 6.3 or later to support JDK14. Maven is not available.

You can run the following command to upgrade:

. / gradlew wrapper – gradle – version = 6.3

build.gradle

The following configuration needs to be added to the Gradle script file

tasks.withType(JavaCompile) {  
options.compilerArgs += "--enable-preview"}
tasks.withType(Test) {
  jvmArgs += "--enable-preview"
}
tasks.withType(JavaExec)
{  jvmArgs += '--enable-preview'}Copy the code

As a final step, change fastJson to Gson

Let’s use a main function to demonstrate this

public static void main(String[] args) { record OutRecord(String name){ } OutRecord outRecord = new OutRecord("xiaodao"); Gson Gson = new Gson(); System.out.println("gson:"+gson.toJson(outRecord)); System.out.println("fastJson:"+JSON.toJSONString(outRecord)); Init ("xiaodao"); System.out.println("gson:"+gson.toJson(holder)); System.out.println("fastJson:"+JSON.toJSONString(holder)); } static class Holder{// Declare a InnerRecord record; InnerRecord(String name){} *@param name * @return */ public static Holder init(String name){ Holder holder = new Holder(); InnerRecord innerRecord = new InnerRecord(name); holder.record = innerRecord; return holder; }}Copy the code

The following output is displayed:

As you can see, fastJson can’t be serialized with either a direct Record or a wrapper class, but Gson can be serialized with a wrapper class

Scatter flowers! Completion of this

About the record, xiaobian personal feel or very good to use, only as a value object, almost can replace the static internal class, simple code. If you want to experience the magic of code, try it yourself

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