LoggerFactory.getLogger cannot be resolved to a type

Question

I setup a basic Java program. I am following this tutorial and have this exact code:

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class HelloWorld {
  public static void main(String[] args) {
    Logger logger = LoggerFactory.getLogger(HelloWorld.class);
    logger.info("Hello World");
  }
}

I have the jars slf4j-api-1.7.5.jar and slf4j-log4j12-1.7.5 jar on my build path. I do not understand what gives, the getLogger method exists in the LoggerFactory class which I can F3 (source code look-up) to. I Googled about this and appear to be the only dope with this problem. Any ideas?

Here is my .classpath for Eclipse:

<xml version="1.0" encoding="UTF-8"?>
<classpath>
   <classpathentry kind="src" path="src"/>
   <classpathentry kind="con" path="org.eclipse.jdit..../>
   <classpathentry kind="lib" path="/home/Desktop/slf4j-api-1.7.5.jar" sourcepath="/home/Desktop/slf4j-api-1.7.5.jar"/>
   <classpathentry kind="lib" path="slf4j-log4j12-1.7.5.jar"/>
   <classpathentry kind="lib" path="log4j-1.2.17.jar"/>
   <classpathentry kind="output" path="bin"/>
</classpath>

When do you get the error? Does Eclipse mark your uses of LoggerFactory (and is `LoggerFactor` in the title a typo?)? Or do you get the error during runtime? — sheltem, Feb 28 '14 at 19:01
If Eclipse can not resolve the class, it is not part of the build path. Go to the properties of your project (by right-clicking it and select properties), then choose "Java build path" and switch to the "Libraries" tab. Is there an entry that points to the slf4j-api-1.7.5.jar? If not, add it. If it is... then that's extremely odd and showing us the .classpath-file of your project might help. — sheltem, Feb 28 '14 at 19:13

score 6 · Accepted Answer · answered Feb 28 '14 at 16:51

6

On the tutorial page you link to, there is the following note:

slf4j-log4j12-1.7.6.jar

Binding for log4j version 1.2, a widely used logging framework. You also need to place log4j.jar on your class path.

Did you include log4j.jar?

answered Feb 28 '14 at 16:51

David Hodgson

854
8
13

I added log4j.jar to my build path but there is still no change. I do not have access to the 1.7.6 slf4j jars on my development box. Should that 0.0.1 difference be causing this error? I can see the method call in my jar's source code. – smuggledPancakes Feb 28 '14 at 17:36
1

Doesn't matter which concrete logging framework is to be used in the end, Logger and LoggerFactory are classes that reside in the slf4j-api. A missing binding or logging implementation would lead to a completely different error. – sheltem Feb 28 '14 at 19:00
I had a spelling error on my path, sorry about this mess – smuggledPancakes Feb 28 '14 at 20:54

score 4 · Answer 2 · answered Jun 12 '14 at 13:01

4

My problem was solved after the inclusion of

slf4j-api-1.7.7.jar and slf4j-simple-1.7.7.jar

on classpath.

answered Jun 12 '14 at 13:01

Alan CN

1,467
1
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score 1 · Answer 3 · edited Dec 17 '18 at 02:40

1

For me, when I added the Maven dependency below, it worked:

<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>

edited Dec 17 '18 at 02:40

craigcaulfield

3,381
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answered Dec 17 '18 at 02:05

Thanuja

11
2

score 0 · Answer 4 · edited May 23 '17 at 12:32

0

You can always use the logger statically instead of using loggerfactory and creating an instance every time you need it:

final static Logger logger = Logger.getLogger(HelloWorld.class);

According to this SO answer, there does not seem to be much overhead of using either way:

What's the overhead of creating a SLF4J loggers in static vs. non-static contexts?

edited May 23 '17 at 12:32

Community

1
1

answered Dec 31 '15 at 17:18

ephemeralCoder

187
2
10

score 0 · Answer 5 · edited Dec 27 '17 at 00:31

0

I solved it with

import org.apache.log4j.Logger;

instead of

import java.util.logging.Logger;

edited Dec 27 '17 at 00:31

Mark

143,421
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answered May 30 '17 at 12:29

yaghob abbasi

96
1
12

LoggerFactory.getLogger cannot be resolved to a type

5 Answers5