How to Solve "Error starting Application Context" in Spring Framework?

 Hello guys, Spring Boot is a popular framework for building Java applications, providing a streamlined development experience. However, like any software, Spring Boot applications can encounter errors during startup. One common error that developers may encounter is the "Error starting ApplicationContext" error. This error typically indicates an issue with the application's configuration or dependencies but it's really hard to find what exactly is wrong and how to fix it. In the past, I have shared tips on how to fix error creating bean error and In this article, we will explore various solutions to fix this error and ensure a successful startup of your Spring Boot application.

How to fix "not a managed type exception" in JPA? [Solution]

Hello folks, JPA (Java Persistence API) is a widely used technology in Java applications for object-relational mapping (ORM) and working with databases. However, when using JPA, you may encounter the "not a managed type" exception, which is a common error that occurs when JPA fails to recognize an entity class as a managed type. This exception can occur due to various reasons, such as incorrect package or class names, missing annotations, or misconfiguration of JPA settings. Fixing this error requires identifying the root cause and taking appropriate steps to resolve it. In this article, we will explore different strategies and solutions to fix the "not a managed type" exception in JPA, helping you overcome this hurdle and successfully work with JPA in your Java applications.

[Solved] java.lang.ClassNotFoundException: org.Springframework.Web.Context.ContextLoaderListener in Java and Spring

Problem : You are getting java.lang.ClassNotFoundException : org.Springframework.Web.
Context.ContextLoaderListener in your Spring-based Java Web application.
Cause: This error comes when you are using the Spring MVC framework in your Java Web application and configured org.springframework.web.context.ContextLoaderListener as a listener in your deployment descriptor also known as web.xml, but the JAR which contains this class is not available in the web application's CLASSPATH.

How to fix org.springframework.beans.factory.BeanCreationException: Error creating bean with name X [Java Spring]

If you are using the Spring framework in your Java application and getting this error during startup it means Spring is not able to initialize the bean X and add it into its application context, Why? There could be multiple reasons like a typo on the spring bean name. Let's take a closer look at the stack trace to find out the real reason:

BeanInstantiationException: Could not instantiate bean class [X]: No default constructor found; nested exception is java.lang.NoSuchMethodException: X.()

Here X is the class, which is declared as Spring bean. The error clearly says that the default constructor is not present in class X.

How to solve java.lang.NoClassDefFoundError: org/springframework/beans/factory/SmartInitializingSingleton in Spring Boot [Solved]

Problem:
I was trying to run a HelloWorld program using Spring Boot when I got this error:

Exception in thread "main" java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration#propertySourcesPlaceholderConfigurer due to internal class not found. This can happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:52)
at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:92)
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForBeanMethod(ConfigurationClassBeanDefinitionReader.java:174)
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:136)

How to Handle REST exception in Spring Boot Application? Example Tutorial

Hello everyone, in this article we are going to take a look at how to handle REST API exceptions in Spring Boot. It is crucial to handle errors correctly in APIs by displaying meaningful messages as it helps API clients to address problems easily. What happens if we don’t handle the errors manually? By default, the spring application throws a stack trace, which is difficult to understand. Stack traces are mainly for developers hence it is useless for API clients. That's why its very important to use proper HTTP code and error messages to convey errors and exception to client and also logging so that support team can better handle them. Ideally you should tell what went wrong and how to fix it? For example, if the error is due to duplicate data then clearly say, already existed, try with a new one. Similarly, if authentication fail then clearly say authentication failed instead of throwing some other exception. 

How to fix cannot determine embedded database driver class for database type NONE

Hello and welcome to the blog post. Today we are going to take a look at a frequently encountered problem in Spring Boot Application. If you are reading this, I'm going to assume that you saw the problem "Cannot determine embedded database driver class for database type NONE" while executing a Spring Boot application. We will understand, when this error appears. For this we will create a simple Spring Boot project as shown below. It demonstrates how I encountered the problem "Cannot determine embedded database driver class for database type NONE".  

Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean

Hello and welcome to the blog post. In this post, we are about to take a look at how to fix the ‘unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean’ in the spring boot application. Let’s understand how to fix this error. But before we dig deep into this issue. Let’s first have a look at when this error appears. 

Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean

The error appears with the following stack trace.

Exception in thread “main” org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.

at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:140)

at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:476)

at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:124)

at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:658)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:355)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:920)

at org.springframework.boot.SpringApplication.run(SpringApplication.java:909)

at Application.main(Application.java:17)

Caused by: org.springframework.context.ApplicationContextException: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean.

at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.getEmbeddedServletContainerFactory(EmbeddedWebApplicationContext.java:190)

at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:163)

at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137)

… 7 more 

Now, let's see some code to understand when this error comes and how to fix it:

SpringBootPracticeApplication.java

package com.practice.springboot;



import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootConfiguration;



@SpringBootConfiguration

public class SpringBootPracticeApplication {



   public static void main(String[] args) {

      SpringApplication.run(SpringBootPracticeApplication.class, args);

   }



}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

   <modelVersion>4.0.0</modelVersion>

   <parent>

      <groupId>org.springframework.boot</groupId>

      <artifactId>spring-boot-starter-parent</artifactId>

      <version>3.0.4</version>

      <relativePath/> <!-- lookup parent from repository -->

   </parent>

   <groupId>com.practice</groupId>

   <artifactId>spring-boot</artifactId>

   <version>0.0.1-SNAPSHOT</version>

   <name>Spring Boot Practice</name>

   <description>Spring Boot Practice Project</description>

   <properties>

      <java.version>17</java.version>

   </properties>

   <dependencies>

      <dependency>

         <groupId>org.springframework.boot</groupId>

         <artifactId>spring-boot-starter-web</artifactId>

      </dependency>



	 <dependency>

       <groupId>org.springframework.boot</groupId>

         <artifactId>spring-boot-starter-test</artifactId>

         <scope>test</scope>

	</dependency>

   </dependencies>

</project>

As you can see from the above program, we have a very simple spring boot project that fails to run as intended. There are a couple of possible solutions to this program. These approaches are discussed below.

How to fix this error?

First of all you need to ensure that your main class has the @SpringBootApplication annotation.

The @SpringBootApplication annotation is comparable to the @EnableAutoConfiguration, @ComponentScan, and @Configuration annotations with their default properties, i.e., allow adding new beans to the context or importing more configuration classes.

SpringBootPracticeApplication.java -- updated

package com.practice.springboot;



import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;



@SpringBootApplication

public class SpringBootPracticeApplication {



   public static void main(String[] args) {

      SpringApplication.run(SpringBootPracticeApplication.class, args);

   }



}

If you have followed the above step or your starter file already contains @SpringBootApplication, you need to make sure your pom.xml file also includes the spring-boot-starter-web or spring-boot-starter-tomcat dependencies, as demonstrated in the example below.

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

   <modelVersion>4.0.0</modelVersion>

   <parent>

      <groupId>org.springframework.boot</groupId>

      <artifactId>spring-boot-starter-parent</artifactId>

      <version>3.0.4</version>

      <relativePath/> <!-- lookup parent from repository -->

   </parent>

   <groupId>com.practice</groupId>

   <artifactId>spring-boot</artifactId>

   <version>0.0.1-SNAPSHOT</version>

   <name>Spring Boot Practice</name>

   <description>Spring Boot Practice Project</description>

   <properties>

      <java.version>17</java.version>

   </properties>

   <dependencies>

      <dependency>

         <groupId>org.springframework.boot</groupId>

         <artifactId>spring-boot-starter-web</artifactId>

      </dependency>



	 <dependency>

       <groupId>org.springframework.boot</groupId>

         <artifactId>spring-boot-starter-test</artifactId>

         <scope>test</scope>

	</dependency>



<!-- Add spring-boot-starter-web or spring-boot-starter-tomcat -->



<dependency>

    <groupId>org.springframework.boot</groupId>

    <artifactId>spring-boot-starter-tomcat</artifactId>

</dependency>



<!-- Add spring-boot-starter-web or spring-boot-starter-tomcat -->



   </dependencies>

</project>

After following the above two approaches, the error finally disappeared and the spring application start successfully as shown from the console.

 .   ____          _            __ _ _

 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \

( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \

 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )

  '  |____| .__|_| |_|_| |_\__, | / / / /

 =========|_|==============|___/=/_/_/_/

 :: Spring Boot ::                (v3.0.4)

2023-03-09T09:46:05.540+05:00  INFO 40009 --- [           main] c.p.s.SpringBootPracticeApplication      : Starting SpringBootPracticeApplication using Java 19.0.1 with PID 40009 (/home/muhammad/IdeaProjects/spring-boot/target/classes started by muhammad in /home/muhammad/IdeaProjects/spring-boot)

2023-03-09T09:46:05.545+05:00  INFO 40009 --- [           main] c.p.s.SpringBootPracticeApplication      : No active profile set, falling back to 1 default profile: "default"

2023-03-09T09:46:06.501+05:00  INFO 40009 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)

2023-03-09T09:46:06.509+05:00  INFO 40009 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]

2023-03-09T09:46:06.510+05:00  INFO 40009 --- [           main] o.apache.catalina.core.StandardEngine    : Starting Servlet engine: [Apache Tomcat/10.1.5]

2023-03-09T09:46:06.585+05:00  INFO 40009 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext

2023-03-09T09:46:06.585+05:00  INFO 40009 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 972 ms

2023-03-09T09:46:06.964+05:00  INFO 40009 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''

2023-03-09T09:46:06.972+05:00  INFO 40009 --- [           main] c.p.s.SpringBootPracticeApplication      : Started SpringBootPracticeApplication in 1.927 seconds (process running for 2.661)

Conclusion

That's all about how to fix "Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean" error in Spring Boot. . The main subject of this post is the Spring Boot problem Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean. 

We have explored two methods to address this issue. The first step is to choose the appropriate Spring annotation, and the second is to add the missing dependency to your build.gradle or pom.xml file. I hope the information in this post has helped you to correct the issue. For more such helpful articles keep following us.

How to fix access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set? [Solved]

Hello and welcome to the blog post. Today we are going to take a look at another frequently encountered issue while working with Spring Boot and Hibernate. The error "Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set" usually comes when Hibernate is unable to determine the appropriate database dialect to use. This error can be fixed by setting the hibernate.dialect property in your Hibernate configuration file. In this post, we'll look at a fix for the issue where a Spring Boot applications' "hibernate.dialect" setting prevents access to dialectresolutioninfo from being null., But before that let's take a look at the Exception itself.

How to Fix Consider defining a bean of type 'package' in your configuration [Solved]

Hello and welcome to another blog post. Today we are going to take a look at one of the most frequently appearing errors in the Spring Boot application. I’m sure most of us have faced a similar issue while working with the Spring Boot application, and the error is ‘consider defining a bean of type package in your configuration’. In general, The error "Consider defining a bean of type 'package' in your configuration" occurs when Spring Boot is unable to find a bean of a specific type that is required by your application. In this article, we will take an in-depth look at why this error appears in the first place. Moving ahead we will learn how to fix this issue. So without further ado let’s jump into it.

How to Fix Spring Boot cannot access REST Controller on localhost (404) Error in Java

Hello guys, if you are getting "cannot access REST Controller on localhost (404)" error in your Spring Boot application and wondering how to solve it then you have come to the right place. Earlier, I have shared how to solved 5 common Spring Framework errors and exception and in this article, we will take a look at the spring boot can’t access rest controller on localhost (404) issue. A 404 Not Found Error for your REST Controllers is a relatively typical problem that many developers encounter while working with Spring Boot applications. In this Spring boot tutorial, let's explore why such an error took place, and later on, we will learn how to fix this issue.

How to Fix Access restriction: The type BASE64Decoder is not accessible due to restriction Error in Eclipse? [Solution]

Hello guys, if you have been using Eclipse for Java development then you might have seen this dreaded  "Access restriction: The type BASE64Decoder is not accessible due to restriction Error" before. This error comes when you are trying to encode String into Base64 using BASE64Decoder in Eclipse because the class BASE64Decoder is not part of JDK's public API, it comes from sun.misc package which is non-public. Though this class is present in JDK and JRE and allows you to encode and decode String into base 64, any access to this class from Eclipse flags as an error in Eclipse IDE. If you compile and run the same program from the command line or NetBeans you will not get this error.

How to Fix javax.net.ssl.SSLHandshakeException: unable to find valid certification path to requested target in Java

Hello guys, this is one of the common errors in a client-server application. The big problem in solving this error is not the error but the knowledge of how client-server SSL handshake works. I have blogged about that before and if you have read that you know that in order to connect to any website or server (like LDAP Server) using SSL, you need to have certificates (public keys) to validate the certificates sends by the website you are connecting. If you don't have the root certificate or public key, which is required to validate the certificate presented by the server in your JRE truststore then Java will throw this error.

How to Fix Unsupported major.minor version 60.0, 59.0, 58.0, 57.0, 56.0, 55.0, 54, 0, 53.0, 52.00, 51.0 Error in Eclipse & Java

The UnsupportedClassVersionError is a big nightmare for Java developers, probably the next biggest after NoClassDefFoundError and ClassNotFoundException but it's slightly easier to solve. The root cause of this error is that your code is compiled using a higher JDK version and you are trying to run it on the lower version. For example, the Unsupported major.minor version 53.0 means your code is compiled in JDK 9 (the class version 52 corresponds to JDK 9) and you are trying to run it on any JRE lower than Java 9, probably JDK 8, 7, or 6.

How to fix java.lang.OutOfMemoryError: unable to create new native thread [Solution]

There are several types of OutOfMemoryError in Java e.g. OutOfMemoryError related to Java heap space and permgen space, and a new one coming in Java 8, Java.lang.OutOfMemoryError: Metaspace. Each and every OutOfMemoryError has its own unique reason and corresponding unique solution. For example, java.langOutOfMemoryError: Java Heap Space comes when the application has exhausted all heap memory and tries to create an object which requires further memory allocation, At that time JVM throws this error to tell the application that it's not possible to create an object.

5 Tips to Fix Exception in thread "main" java.lang.NoClassDefFoundError in Java, Examples

NoClassDefFoundError in Java
The Exception in thread "main" java.lang.NoClassDefFoundError is a common error in Java that occurs if a ClassLoader cannot find a particular class in the classpath while trying to load it. The Exception in thread "main" suggests that this error has occurred in the main thread, the thread which is responsible for running the Java application. This error can occur to any thread, but if it happens in the main thread, then your program will crash because Java program runs only until main() thread is running or any other non-daemon thread is running. As per Javadoc, NoClassDefFoundError can be thrown during the linking or loading of the class file. 

java.lang.IllegalStateException: getOutputStream() has already been called for this response

This error comes when you call to include() or forward() method after calling the getOutputStream() from ServletResponse object and writing into it.  This error is similar to java.lang.IllegalStateException: getWriter() has already been called for this response error, which we have seen in the earlier article.

This is the exception:
org.apache.jasper.JasperException: java.lang.IllegalStateException: getOutputStream() has already been called for this response
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:502)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:424)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
HelloServlet.doGet(HelloServlet.java:25)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:723)

and here is the root cause :

How to fix java.lang.IllegalStateException: getWriter() has already been called for this response [Solution]

This error comes when a Servlet calls the getOutputStream() method on the response object for writing something after calling the include() method. Suppose a Servlet calls the include() method to load the response of a JSP. Since JSP has already written the response on it hence again opening OutputStream on the response object is illegal, you get the java.lang.IllegalStateException: getWriter() has already been called for this response error. This error also comes when you try to include the response of another Servlet and then tries to write something on the output stream again. In short, your Servlet should never write anything on the response object after calling the include() method. 

How to fix java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory

Problem: You are getting java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory in your Java program, which uses a logging framework to log messages into a log file.  It could be direct dependency or indirect dependency due to any framework e.g. Spring, Hibernate, or any open-source library like jackson or any other JSON parsing library.

How to create User Defined Exception class in Java? Example Tutorial

Java has very good support for handling Errors and Exceptions, It has a well-defined Exception hierarchy and language level support to throw and catch Exceptions and deal with them. Java Programmers often deal with built-in exceptions from java.lang package and several others which are already defined in JDK API like NullPointerException. If you have read Effective Java, you may remember the advice of Joshua Bloch regarding Exception. According to him, you should try to reuse the Exception classes provided in the JDK, like IndexOutOfBoundException, ArithmeticException, IOException, and java.lang.ArrayIndexOutOfBoundsException , instead of creating new ones for a similar purpose.