Failed to instantiate [org.springframework.web.servlet.handlermapping]

Answer:

When you see the error message “failed to instantiate [org.springframework.web.servlet.handlermapping]”, it usually means that there was an issue with initializing or creating an instance of the Spring MVC handler mapping.

The handler mapping is responsible for mapping incoming requests to the appropriate controller methods based on the requested URL. It is an essential component in the Spring MVC framework.

To fix this error, you need to ensure that the handler mapping bean is correctly configured in your Spring configuration file (usually XML or JavaConfig).

Here’s an example of how to configure a simple handler mapping using JavaConfig:

@Configuration
@EnableWebMvc
public class AppConfig implements WebMvcConfigurer {
  
  @Override
  public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
    // Enable serving static resources
    configurer.enable();
  }
  
  @Bean
  public HandlerMapping handlerMapping() {
    RequestMappingHandlerMapping handlerMapping = new RequestMappingHandlerMapping();
    // Additional configuration for the handler mapping
    // e.g., set order, custom interceptors, etc.
    return handlerMapping;
  }
  
  // Other configuration methods...
}
  

In this example, we have a JavaConfig class named “AppConfig” that implements the “WebMvcConfigurer” interface. The “WebMvcConfigurer” interface provides various methods for configuring Spring MVC.

We override the “configureDefaultServletHandling” method to enable serving static resources (e.g., CSS, JS files) using the default servlet. This step is optional but required if you want to serve static resources without explicitly mapping them in the handler mapping.

The “handlerMapping” method is annotated with “@Bean”, which tells Spring to create an instance of the “RequestMappingHandlerMapping” class and register it as a bean in the Spring application context. You can customize the handler mapping by adding additional configuration to the “RequestMappingHandlerMapping” instance.

Make sure that you have the necessary Spring MVC dependencies in your project’s build file (e.g., Maven, Gradle).

By correctly configuring the handler mapping, you should be able to resolve the “failed to instantiate [org.springframework.web.servlet.handlermapping]” error and successfully run your Spring MVC application.