EC
ClassNotFoundException
JavaFATALNotableClasspath

Class not found on classpath

Quick Answer

Add the missing JAR as a dependency in Maven/Gradle and verify the class name is spelled correctly.

What this means

Thrown when an application tries to load a class by name but the class is not on the classpath at runtime.

Why it happens
  1. 1Required JAR not declared in pom.xml or build.gradle
  2. 2Typo in the class name string passed to Class.forName

Fix

Add Maven dependency

Add Maven dependency
<dependency>
  <groupId>org.postgresql</groupId>
  <artifactId>postgresql</artifactId>
  <version>42.7.0</version>
</dependency>

Why this works

Maven downloads the JAR and adds it to both compile and runtime classpaths.

Code examples
Triggerjava
Class.forName("com.example.Missing"); // ClassNotFoundException
Safe dynamic loadjava
try {
    Class<?> c = Class.forName(className);
} catch (ClassNotFoundException e) {
    log.error("Driver not on classpath: {}", className);
}
JDBC driver loadjava
Class.forName("org.postgresql.Driver");
Connection conn = DriverManager.getConnection(url, user, pass);
Sources
Official documentation ↗

Java SE Documentation

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