Programming Issues

Issues

Popup Message – No tests found with test runner JUnit5

The unusual Popup Message “No tests found with test runner ‘JUnit5’ ” is often seen when running test classes in spring boot application In eclipse, when you run the JUnit test case in your spring boot application, some time you’ll encounter a problem that eclipse can’t find any tests. In

java.lang.IllegalStateException ThreadPoolTaskScheduler not initialized

ThreadPoolTaskScheduler is used to create a thread pool that manages scheduler task. These threads will run periodically based on the time interval that has been configured. Configured parameters must be initialized before the schedulers are used. Root Cause The custom thread pool is created in the spring boot application. Schedulers

java.lang.IllegalArgumentException: ‘poolSize’ must be 1 or higher

By Default, the Spring boot scheduler runs using default thread pool of size one. ThreadPoolTaskScheduler allows to create a custom thread pool with any pool size. The size of the pool must be set to 1 or higher. The size of the pool must be set higher if you are

java.lang.IllegalStateException: Encountered invalid @Scheduled method ‘task’: Invalid time zone specification

The exception “java.lang.IllegalStateException: Encountered invalid @Scheduled method ‘task’: Invalid time zone specification”  is thrown in the spring boot scheduler on invalid time zone configured. Schedulers are the tasks that run at a certain interval on a regular basis. Spring boot offers good support for spring boot schedulers. It is possible to configure these schedulers as cron job. By default, cron time

Invalid initialDelayString cannot parse into long

Spring boot provides good support for the creation of spring boot schedulers. Schedulers are the tasks that run periodically at a specific interval. As soon as the application starts, these schedulers will run. Spring boot allows these schedulers to be started after a certain delay period. This delay is configured

Invalid fixedDelayString cannot parse into long

The scheduler interval is configured in milliseconds in spring boot application. The duration is a long value defined in @Scheduler configuration in fixedDelay variables. You can configure these values as a string parameter. If any error occurred when the string was converted to long, this exception will be thrown from

Unexpected error occurred in scheduled task

Schedulers in spring boot framework runs the configured the task method periodically. If any error occurred in the task method, the unexpected error exception is thrown by the spring boot. This is due to the logical issue in the code. Exception 2019-10-10 12:14:00.007 ERROR 49298 --- [ scheduling-1] o.s.s.s.TaskUtils$LoggingErrorHandler :

Encountered invalid Scheduled method input string

In spring boot framework, schedulers can be configured using cron jobs. If there are any issues related to cron job expression, Scheduler can not define the scheduled time frame. In this scenario, the scheduler will throw an input error and will not start the scheduler. Exception 2019-10-10 12:03:16.181 ERROR 48515

Invalid fixedRateString cannot parse into long

The scheduler interval is configured in milliseconds in spring boot application. The duration is a long value defined in @Scheduler configuration in fixedRate and fixedDelay variables. You can configure these values as a string parameter. If any error occurred when the string was converted to long, this exception will be

java.lang.IllegalArgumentException: null @Scheduled

Spring boot scheduler throws “Application run failed, java.lang.IllegalArgumentException: null” exception if the scheduler is configured with invalid value in @Scheduler annotation. The scheduler in the spring boot application is failed to start. The scheduler argument is invalid To make this scheduler functional, the proper value should be added. Exception 2019-10-10

Encountered invalid @Scheduled method ‘task’: Exactly one of the ‘cron’, ‘fixedDelay(String)’, or ‘fixedRate(String)’ attributes is required

The exception “Encountered invalid @Scheduled method ‘task’: Exactly one of the ‘cron’, ‘fixedDelay(String)’, or ‘fixedRate(String)’ attributes is required” is thrown due to error while loading the scheduler bean at the startup of the spring boot application. Spring boot application allows scheduler to run on a regular basis. If spring boot does not load bean due to the configuration of the scheduler then

restartedMain Unresolved compilation problem

Spring boot application loads all the beans using bean factory. If any error occurred while invoking the java classes, this exception is thrown Exception Exception in thread "restartedMain" java.lang.reflect.InvocationTargetException at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.base/java.lang.reflect.Method.invoke(Unknown Source) at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) Caused by: java.lang.Error: Unresolved compilation problem: SpringApplication

Unable to open JDBC Connection for DDL execution

The spring boot application creates database connection in startup. The EntityManager class is responsible for basic CRUD database operation. If the creation of EntityManger is failed, then this error is shown Exception 2019-10-07 13:46:48.751 ERROR 5068 --- [ restartedMain] o.s.boot.SpringApplication : Application run failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name

HikariPool-1 – Exception during pool initialization. java.sql.SQLSyntaxErrorException: Access denied for user ‘root’@’localhost’ to database

The exception “java.sql.SQLSyntaxErrorException: Access denied for user ‘root’@’localhost’ to database ‘testdb’” is thrown if you are using mysql database first time or newly installed. If you start the spring boot application, the jpa will try to create a database conection pool. If any error is thrown from the database, this

Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be configured. Reason: Failed to

If the spring-boot-starter-data-jpa dependency is added in the spring boot pom.xml file, when the spring boot application starts the exception “Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be configured. Reason: Failed to determine a suitable driver class” will be thrown. In this