apache/hadoop · error · ClassNotFoundException
Class {} not found
Error message
Class {} not found What it means
Error "Class {} not found" thrown in apache/hadoop.
Source
Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/conf/Configuration.java:2628
*/
public InetSocketAddress updateConnectAddr(String name,
InetSocketAddress addr) {
final InetSocketAddress connectAddr = NetUtils.getConnectAddress(addr);
setSocketAddr(name, connectAddr);
return connectAddr;
}
/**
* Load a class by name.
*
* @param name the class name.
* @return the class object.
* @throws ClassNotFoundException if the class is not found.
*/
public Class<?> getClassByName(String name) throws ClassNotFoundException {
Class<?> ret = getClassByNameOrNull(name);
if (ret == null) {
throw new ClassNotFoundException("Class " + name + " not found");
}
return ret;
}
/**
* Load a class by name, returning null rather than throwing an exception
* if it couldn't be loaded. This is to avoid the overhead of creating
* an exception.
*
* @param name the class name
* @return the class object, or null if it could not be found.
*/
public Class<?> getClassByNameOrNull(String name) {
Map<String, WeakReference<Class<?>>> map;
synchronized (CACHE_CLASSES) {
map = CACHE_CLASSES.get(classLoader);
if (map == null) {View on GitHub (pinned to 2add963021)
Solutions
- Add the missing class to the classpath or correct the class name in the configuration property.
Example fix
Fix the property to the fully-qualified class name and ship the jar.
When it happens
Trigger: Raised at runtime when the documented precondition or configuration requirement for this operation is violated.
Common situations: Misconfigured or missing property, invalid user input, or calling the API before its prerequisites are met.
AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22).
Data as JSON: /api/errors/359d689b54d34756.
Report an issue: GitHub.