Can't reproduce. Can you share a sample "Hello World" project where it could be reproduced? 

See also https://youtrack.jetbrains.com/issue/IDEA-177758

Konstantin Annikov

Has create a sample project with 3 java classes. In general:

• Mainclass.main will create a Example1 instance
• Mainclass.main will call public method Example1.f1
• Mainclass.main will call public method Example1.callf2, which will create a instance of Example2, then call public method Example2.f2

In Mainclass.java:

public class Mainclass {
    public static void main(String[] argv) {
        Example1 exp1 = new Example1("Create a Example class 1 from Mainclass");
        exp1.f1("Mainclass");
        exp1.callf2();
    }
}

In Example1.java:

public class Example1 {
    private String attr;

    public Example1(String str) {
        System.out.println(str);
        this.attr = str;
    }

    public void f1(String s) {
        System.out.println("f1 called from " + s);
    }

    public void callf2() {
        Example2 exp2 = new Example2("ttt");
        exp2.f2("example class 1");
    }
}

In Example2.java:

public class Example2 {
    public Example2(String str) {
        System.out.println(str);
    }

    public void f2(String s) {
        System.out.println("f2 called from " + s);
    }
}

Code screenshot as follows:

But UML diagram as follows:

No dependency at all. It does not show the <<create>> dependencies between Mainclass and Example1, or between Example1 and Example2. It also doesn't show the usage in which Example1 calls Example2's method.

UML diagram shows dependencies of 1 class only. You need to add other classes (Right-click on diagram | Add class to diagram). 

Here is the usability problem about that: https://youtrack.jetbrains.com/issue/IDEA-81834

Konstantin Annikov

Sorry but still can not understand. When I open the diagram of 1 class (like Mainclass above) and manually add other classes (Example1, Example2) by right-click, there's still no dependencies.

I find some UML diagrams created by other people using IDEA on the internet. I circle some lines in one diagram below; What I really want to know is, how can these white lines (showing dependencies, assocation, aggregation etc.) automatically generated in the diagram?

(this diagram is found in https://zhuanlan.zhihu.com/p/175122754)

Here is the video how to achieve that: https://youtu.be/hAgVxfDKoGw

Konstantin Annikov

Thank's for your attention. I've repeat what you do in the video, but still cannot show dependencies.

My video is here: https://youtu.be/PeGmfUW0X7k

What is the version of IntelliJ IDEA? 

As a general troubleshooting step, please:

1. Reproduce the issue in a brand new Java project (without Maven/Gradle etc)

2. Disable all custom plugins: https://www.jetbrains.com/help/idea/managing-plugins.html#disable-plugin

3. Reset settings to default via File | Manage IDE Settings | Restore Default Settings

Konstantin Annikov

The version copied from "Help -> About" menu：

IntelliJ IDEA 2020.3.2 (Ultimate Edition)
内部版本号 #IU-203.7148.57, 构建于 January 26, 2021
Licensed to Chiachiun Than
Subscription is active until September 6, 2021.
For educational use only.
运行时版本: 11.0.9.1+11-b1145.77 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Windows 10 10.0
GC: ParNew, ConcurrentMarkSweep
Memory: 974M
Cores: 8
Non-Bundled Plugins: Statistic, com.intellij.zh, CheckStyle-IDEA, org.jetbrains.kotlin, Pythonid

Seems that the problem lies in your official Chinese(Simplified) Language Pack plugin (version 203.596). I reset the IDE settings and enable that plugin and the dependencies still cannot be shown; but after I disable it and restart IDE, the bug disappears. 

It's ok for me to use a pure English interface, however still hope to have a fix as soon as possible. You can report it to your plugin team. 

This has been fixed already in EAP version of IntelliJ IDEA: 

https://youtrack.jetbrains.com/issue/IDEA-256254

I can't either, it's not fixed yet

Runtime version: 11.0.13+7-b1751.25 amd64

Chinese ​(Simplified)​ Language Pack / 中文语言包

Version 223.143

2652127675 Please check if the problem reproduces in the latest build from https://www.jetbrains.com/idea/download . If the problem remains contact JetBrains support at https://intellij-support.jetbrains.com/hc/en-us/requests/new and provide a couple of screenshots showing your problem. Thank you!

Hi, I downloaded the ultimate Version for students today and came across the same problem. It is strange that nothing occur after I clicking the show dependencies button. Already reported the problem to your suggested link, hope to see how it goes soon.