运行我的测试日志记录代码时，我得到一个窗口，上面写着"A java exception has occurred"

Question

这里是初学者。它还留下了一些调试信息，但我不知道它意味着什么。

import java.sql.SQLException;
import org.apache.log4j.*;  

public class Example{  

static Logger Log = Logger.getLogger(Example.class);  

public static void main(String[] args)throws IOException,SQLException
{  
Log.debug("Hello this is a debug message");  
Log.info("Hello this is an info message");  
}  
}  

错误消息：

at org.apache.logging.slf4j.SLF4JLoggerContext.getLogger(SLF4JLoggerContext.java:39)
at org.apache.log4j.Category.<init>(Category.java:82)
at org.apache.log4j.Logger.<init>(Logger.java:33)
at org.apache.log4j.Category$PrivateAdapter.newLogger(Category.java:523)
at org.apache.log4j.Category.getInstance(Category.java:124)
at org.apache.log4j.Category.getInstance(Category.java:104)
at org.apache.log4j.Category.getInstance(Category.java:134)
at org.apache.log4j.Logger.getLogger(Logger.java:41)
at Example.<clinit>(Example.java:7)
Caused by: java.lang.ClassNotFoundException: org.slf4j.Logger
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
... 9 more

如有任何帮助，我们将不胜感激。

Answer 1

您需要声明依赖项。如果您使用maven，请将以下内容添加到pom.xml

<!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
<dependencies>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.17.0</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.17.0</version>
</dependency>
</dependencies>

或者，如果您使用渐变，请将以下内容添加到build.gradle:

dependencies {
compile group: 'org.apache.logging.log4j', name: 'log4j-api', version: '2.17.0'
compile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.17.0'
}