向Maven项目添加库

Question

I have created simple Maven Java project in Eclipse.

In package src/main/java I have create simple tst class and planing to use log4j there:

import java.util.Scanner;
import org.apache.log4j.Logger;

public class tst {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("hello");
        Scanner scan=new Scanner(System.in);
    }
}

I have added log4j in dependencies:

I expect Maven will download log4j jar for my project. Instead of that I have error Missing artifact log4j:log4j:jar:1.2 .

How to fix this problem? Is it possible to know what versions are available in log4j project?

Answer 1

mvnrepository.com says that the project Apache Log4j was move to Log4j Core . So try to update the artifact with this one:

<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.11.1</version>
</dependency>

When you add a library with Maven, always check the correct version in mvnrepository.com

And if you still have the error, try to update maven dependencies. Right click on the project and select

Maven -> Update Project

Sometimes when you update project libraries with Maven, Eclipse isn't able to download it directly and you have to force the refresh of the dependencies.

Answer 2

The problem is simply that there is no log4j in version 1.2.

Try version 1.2.17.

Just follow the path you chose, but use 1.2.17 instead of 1.2.