I am trying to implement a server using spring boot and jpa.

I wanted to add a method to update values in the database (MySQL) and therefore, I added the method by referring [this](https://stackoverflow.com/a/52576978) answer. Since then the program does not work and throws this exception:

```none
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'requestMappingHandlerAdapter' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Unsatisfied dependency expressed through method 'requestMappingHandlerAdapter' parameter 2; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mvcValidator' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.validation.Validator]: Factory method 'mvcValidator' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/validation/ParameterNameProvider
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:797) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:538) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1336) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1176) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:556) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:897) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) ~[spring-context-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at com.app.cashier.CashierApplication.main(CashierApplication.java:12) ~[classes/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mvcValidator' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.validation.Validator]: Factory method 'mvcValidator' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/validation/ParameterNameProvider
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:655) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:635) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1336) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1176) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:556) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1307) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1227) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:884) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:788) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    ... 20 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.validation.Validator]: Factory method 'mvcValidator' threw exception; nested exception is java.lang.NoClassDefFoundError: javax/validation/ParameterNameProvider
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:650) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    ... 34 common frames omitted
Caused by: java.lang.NoClassDefFoundError: javax/validation/ParameterNameProvider
    at org.springframework.boot.autoconfigure.validation.ValidatorAdapter.create(ValidatorAdapter.java:134) ~[spring-boot-autoconfigure-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.autoconfigure.validation.ValidatorAdapter.getExistingOrCreate(ValidatorAdapter.java:117) ~[spring-boot-autoconfigure-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.autoconfigure.validation.ValidatorAdapter.get(ValidatorAdapter.java:109) ~[spring-boot-autoconfigure-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration.mvcValidator(WebMvcAutoConfiguration.java:458) ~[spring-boot-autoconfigure-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    ... 35 common frames omitted
Caused by: java.lang.ClassNotFoundException: javax.validation.ParameterNameProvider
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:602) ~[na:na]
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na]
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na]
    ... 44 common frames omitted

```

Model class :

```
package com.app.cashier.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.validation.constraints.Min;
import java.util.Date;

@Entity
public class Items {

    @Id
    @GeneratedValue
    @Column(name = "itemId")
    private int itemId;

    @Column(name = "itemName")
    private String itemName;

    @Column(name = "expirationDate")
    private Date expirationDate;

    @Column(name = "price")
    private float price;

    @Column(name = "batch")
    private Date batch;

    @Min(value = 0, message = "Available amount is empty")
    @Column(name = "availableAmount")
    private int availableAmount;

    @Column(name = "flavour")
    private String flavour;

    @Column(name = "liter")
    private float liter;

    @Column(name = "type")
    private String type;

    public Items() {
    }

    public int getItemId() {
        return itemId;
    }

    public void setItemId(int itemId) {
        this.itemId = itemId;
    }

    public String getItemName() {
        return itemName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }

    public Date getExpirationDate() {
        return expirationDate;
    }

    public void setExpirationDate(Date expirationDate) {
        this.expirationDate = expirationDate;
    }

    public float getPrice() {
        return price;
    }

    public void setPrice(float price) {
        this.price = price;
    }

    public Date getBatch() {
        return batch;
    }

    public void setBatch(Date batch) {
        this.batch = batch;
    }

    public int getAvailableAmount() {
        return availableAmount;
    }

    public void setAvailableAmount(int availableAmount) {
        this.availableAmount = availableAmount;
    }

    public String getFlavour() {
        return flavour;
    }

    public void setFlavour(String flavour) {
        this.flavour = flavour;
    }

    public float getLiter() {
        return liter;
    }

    public void setLiter(float liter) {
        this.liter = liter;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }
}

```

Repository :

```
package com.app.cashier.repository;

import com.app.cashier.model.Items;
import org.springframework.data.jpa.repository.JpaRepository;

public interface ItemRepository extends JpaRepository<Items, Integer> {
}

```

Resource :

```
package com.app.cashier.resource;

import com.app.cashier.model.Items;
import com.app.cashier.repository.ItemRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping(value = "/rest/items")
public class ItemsResource {

    @Autowired
    ItemRepository itemRepository;

    @GetMapping(value = "/all")
    public List<Items> getAll(){
        return itemRepository.findAll();
    }

    @PostMapping(value = "/load")
    public List<Items> persist(@RequestBody final Items item){
        itemRepository.save(item);
        return itemRepository.findAll();
    }
}

```

Even though I removed the `update` method, it continues throwing this exception. How can I fix this?