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…

com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.…

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…

Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be configured exception occurs when the datasource url is not configured in the spring boot…

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…

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…

Spring boot application loads all the beans using bean factory. If any error occurred while invoking the java classes, this exception is thrownExceptionException in thread "restartedMain" java.lang.reflect.InvocationTargetException at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)…

The Exactly one of the ‘cron’, ‘fixedDelay(String)’, or ‘fixedRate(String)’ attributes is required exception occurs when an invalid value is provided in cron or fixedDelay(String) or fixedRate(String) in the @Scheduled annotation.…

The spring boot @Scheduled method is not working and throws Application run failed, java.lang.IllegalArgumentException: null exception if the scheduler is configured with an invalid value in the @Scheduled annotation. The…

The spring boot exception Field in required a bean of type that could not be found occurs when a field in the class is auto-wired as a bean type that…

The spring boot exception org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type available: expected single matching bean but found occurs when the bean is auto-wired that matches two or more loaded beans…

The spring boot exception org.springframework.beans.BeanInstantiationException: Failed to instantiate: Constructor threw exception occurs when the default constructor in a bean throws exception when the bean is created. The bean is auto-wired…

The spring boot exception org.springframework.beans.BeanInstantiationException: Failed to instantiate: No default constructor found occurs when no default constructor is found in a bean when the bean is created. The bean is…

The spring boot exception BeanCurrentlyInCreationException: Error creating bean with name: Requested bean is currently in creation happens when two beans are in circular dependences with each other. If the bean…

The spring boot exception org.springframework.beans.BeanInstantiationException: Failed to instantiate: Factory method threw exception occurs when the abstract class could not find the implemented class while auto-wiring using the factory method. The…

The spring boot exception BeanInstantiationException: Failed to instantiate happens when the bean can’t instantiate when auto-wiring in another bean. If the bean is instantiated in another bean, the bean either…

The spring boot exception org.springframework.beans.factory.BeanCreationException: Error creating bean with name happens when a problem occurs when the BeanFactory creates a bean. If the BeanFactory encounters an error when creating a…

The spring boot exception org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name defined in file: Unsatisfied dependency expressed through field occurs when a problem occurs when a bean auto-wired on other beans…

The spring boot exception Missing URI template variable for method parameter of type String occurs when the path variable name in the @RequestMapping annotation is different from the @PathVariable name. The name of the path variable should be the same in @RequestMapping and @PathVariable. If there is some mismatch, the exception Missing URI template variable for method parameter of type String would be thrown.The path variable is added as part of the request url in the @RequestMapping annotation. The path variable is covered by curly brackets. The path variable is added to the method parameter with a @PathVariable annotation. The name of the method parameter and the name of the path variable should be the same to avoid an exception Missing URI template variable ” for method parameter of type String.ExceptionThe exception Missing URI template variable for method parameter of type String will be shown in the browser as below.Whitelabel Error Page This application has no explicit mapping for /error, so you are seeing this as…

java.lang. IllegalArgumentException: URI is not absolute occurs when a relative url is used to identify the resource. In the spring boot RestTemplate, the complete url will be used to invoke…