Issues
java.util.concurrent.RejectedExecutionException: rejected from java.util.concurrent.ThreadPoolExecutor
The java.util.concurrent.RejectedExecutionException: rejected from java.util.concurrent.ThreadPoolExecutor error occurs when the thread pool queue is full and no further threads can be created in spring boot. If the ThreadPoolTaskExecutor could not create a thread or could not add it to the queue, the request will be dropped with rejected_thread_execution and the exception
SimpleAsyncUncaughtExceptionHandler : Unexpected exception occurred invoking async method:
Spring boot Exception SimpleAsyncUncaughtExceptionHandler : Unexpected exception occurred invoking async method: is thrown if an exception is thrown from the @Async annotation method. This error is due to either to a coding problem or to a logical issue. If the error has been corrected, this exception SimpleAsyncUncaughtExceptionHandler : Unexpected exception
Cannot load driver class: com.mysql.jdbc.Driver
The database exception Cannot load driver class: com.mysql.jdbc.Driver occurs if there is a disparity between mysql driver class, mysql driver jar version and mysql database version. The java application attempts to load a driver class from the mysql database driver jar. If the driver class is unable to load, the
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The spring boot exception com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure happens when the java mysql database driver is unable to connect to mysql database. The Java application was unable to establish communication between mysql database driver and mysql database. The Jdbc connection between the java and mysql database could not be established.
required a bean of type ‘org.springframework.web.client.RestTemplate’ that could not be found.
The required a bean of type ‘org.springframework.web.client.RestTemplate’ that could not be located. spring boot occurs when the RestTemplate is auto-wired without bean creation. The RestTemplate cannot be auto-wired unless the bean creation configuration is specified. Spring boot cannot locate the RestTemplate because it is not in the loaded bean. The
java.lang.IllegalStateException: Ambiguous mapping. Cannot map method
The spring boot exception IllegalStateException: Ambiguous mapping. Cannot map method occurs when two methods in the rest controller class are configured with the same request mapping url. Two methods in the rest controller class should not be configured using the same url. The exception will be shown as BeanCreationException: Error
NoSuchBeanDefinitionException: No bean named available
The spring boot exception org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named available and org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named is defined happens when you try to access a bean that is not available or is not defined in the spring boot context. If the bean is not available when injecting the spring boot bean programmatically
NoSuchBeanDefinitionException: No qualifying bean of type
The spring boot exception org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type available and org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type defined occurs when the bean is not available or defined while auto-wired in another class. If the bean is not available when the spring boot bean is annotated by @Autowired from the
AnnotationConfigApplicationContext has not been refreshed yet
In the spring boot web application development, you may need to use Application Context to handle loaded beans.The Application context contains all the references to the loaded beans. Spring boot provides a handle for the context of the application. If you use the application context, you may encounter an error
JsonbException: Can’t deserialize JSON array into: class
The javax.json.bind.JsonbException: Can’t deserialize JSON array into: class exception occurs when you try to convert json string data to a java object. If the json string contains an array of objects and attempts to deserialize the json string to a json object, the array of objects could not be assigned
JsonbException: Cannot create instance of a class: class, No default constructor found.
The javax.json.bind.JsonbException: Cannot create instance of a class: class, No default constructor found. exception occurs when no default constructor is found in the java bean class. The spring boot default implementation for json binding api is org.eclipse.yasson. If no default constructor is found, the yasson code will throw this exception
can not access a member of class with modifiers “private”
The ReflectionUtils can not access a member of class with modifiers “private” exception occurs when the default constructor or method is configured as private in the java bean class. If the class method or properties are configured as private, the java reflection can not access the member of class with
JSON Binding provider org.eclipse.yasson.JsonBindingProvider not found
The javax.json.bind.JsonbException: JSON Binding provider org.eclipse.yasson.JsonBindingProvider not found exception occurs when the java.json.bind maven dependency is added and JSON bind implementation dependency is not added in the spring boot maven. As the implemented class is not available in the class path, the exception java.lang.ClassNotFoundException: org.eclipse.yasson.JsonBindingProvider will be thrown. The exception
JndiDataSourceAutoConfiguration not loaded because did not find property
Auto configurations are one of the best features at spring boot. Spring boot supports auto-configured datasource. The credentials for the database are included in application.properties. Spring boot builds a datasource object dynamically from the configurations. If an error occurs in the initialization phase of the datasource, the error will be
BCryptPasswordEncoder Bad strength Spring Boot Security
In the spring boot security application, The error message “Exception in thread “main” java.lang.IllegalArgumentException: Bad strength” is seen when the application starts. The BCryptPasswordEncoder is throwing this exception as it cannot create and initialize the object. Here, we will see about this exception in this post. The spring boot security