Getting JpaSystemException: Could not set field value [2] value by reflection when trying to save object in mySql DB by using spring boot

Question

I have checked all the related questions in stackoverflow but still not able to resolve the issue. Please help me out in this. Included all the required details below. Please let me know if any further details are required. First time asking the question so, help me if any mistakes in the question i will edit it.

Main class

            package com.example;

        import java.util.concurrent.TimeUnit;

        import javax.sql.DataSource;

        import org.apache.catalina.connector.Connector;
        import org.apache.log4j.Logger;
        import org.hibernate.SessionFactory;
        import org.springframework.beans.factory.annotation.Autowired;
        import org.springframework.boot.SpringApplication;
        import org.springframework.boot.autoconfigure.SpringBootApplication;
        import org.springframework.boot.builder.SpringApplicationBuilder;
        import org.springframework.boot.context.embedded.EmbeddedServletContainerFactory;
        import org.springframework.boot.context.embedded.tomcat.TomcatConnectorCustomizer;
        import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
        import org.springframework.boot.web.servlet.ErrorPage;
        import org.springframework.boot.web.support.SpringBootServletInitializer;
        import org.springframework.context.ApplicationContext;
        import org.springframework.context.annotation.Bean;
        import org.springframework.http.HttpStatus;
        import org.springframework.orm.hibernate4.LocalSessionFactoryBuilder;

        import com.dto.Product;

        @SpringBootApplication

        public class Application extends SpringBootServletInitializer{

             @Override
                protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
                return application.sources(Application.class);
                }

            private static final Logger LOGGER = Logger.getLogger(Application.class); 

            public static void main(String[] args) {  
            try{
            ApplicationContext ctx = SpringApplication.run(Application.class, args); 
            System.out.println(ctx);
            LOGGER.info("Spring Boot Beans:");
            LOGGER.info("Spring boot is ready");
            }catch(Exception e){
                LOGGER.error(e);
            }
            }

            @Bean
            public EmbeddedServletContainerFactory tomcatEmbeddedServletContainerFactory() {
            TomcatEmbeddedServletContainerFactory factory = new TomcatEmbeddedServletContainerFactory();

            factory.addConnectorCustomizers(new TomcatConnectorCustomizer() {
                @Override
                public void customize(Connector connector) {
                connector.setProperty("maxKeepAliveRequests", "1");
                connector.setProperty("connectionTimeout", "20000");
                connector.setProperty("keepAliveTimeout", "1");
                connector.setProperty("maxThreads", "250");
                connector.setURIEncoding("UTF-8");
                }
            });
            // Set timeout for tomcat and custom error pages.
            factory.setSessionTimeout(10, TimeUnit.MINUTES);
            factory.setContextPath("/spring-boot");
            factory.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND, "/404.html"));
            factory.addErrorPages(new ErrorPage(HttpStatus.INTERNAL_SERVER_ERROR, "/500.html"));
            return factory;
            }

            @Autowired
            DataSource dataSource;

            @Bean
            public SessionFactory sessionFactory(){

            return new LocalSessionFactoryBuilder(dataSource)


                    .addAnnotatedClass(Product.class)
                        .buildSessionFactory();


            }
        }

DAO class

package com.example;

import java.math.BigDecimal;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.jboss.logging.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import com.dto.Product;



@Repository
@Transactional
public class DAOClass {

    private static Logger logger = Logger.getLogger(DAOClass.class);

    @Autowired
    SessionFactory factory ;

    public void saveProduct(){
        Session session = factory.openSession();
        Transaction transaction = null;
         transaction = session.beginTransaction();
        Product product = new Product("TestProduct",new BigDecimal(111));
        session.save(product);
        transaction.commit();



    }


}

Product entity class

package com.dto;

import java.io.Serializable;
import java.math.BigDecimal;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

import org.hibernate.annotations.GenericGenerator;
@Entity
@Table(name="PRODUCT")
public class Product implements Serializable{

    private static final long serialVersionUID = -1231235L;

    @Id
    @GenericGenerator(name="marksIdGenerator" , strategy="increment")
    @GeneratedValue(generator="marksIdGenerator")
    @Column(name = "PRODUCT_ID")
    private Integer productId;

    @Column(name = "PRODUCT_NAME")
    private String productName;

    @Column(name = "PRICE")
    private BigDecimal price;

   public Product(){}

/* (non-Javadoc)
 * @see java.lang.Object#toString()
 */
@Override
public String toString() {
    return "Product [productId=" + productId + ", productName=" + productName + ", price=" + price + "]";
}

public Product(Integer productId, String productName, BigDecimal price) {
    super();
    this.productId = productId;
    this.productName = productName;
    this.price = price;
}

public Product( String productName, BigDecimal price) {
    super();
    this.productName = productName;
    this.price = price;
}
/**
 * @return the productId
 */
public int getProductId() {
    return productId;
}
/**
 * @param productId the productId to set
 */


public void setProductId(Integer productId) {
    this.productId = productId;
}
/**
 * @return the productName
 */


public String getProductName() {
    return productName;
}
/**
 * @param productName the productName to set
 */
public void setProductName(String productName) {
    this.productName = productName;
}
/**
 * @return the price
 */


public BigDecimal getPrice() {
    return price;
}
/**
 * @param price the price to set
 */
public void setPrice(BigDecimal price) {
    this.price = price;
};

}

application.properties file

spring.datasource.url=jdbc:mysql://localhost:3306/MyDb
spring.datasource.username=root
spring.datasource.password=677234
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.tomcat.max-active=5
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.ddl-auto =update
spring.jpa.show-sql = true
server.port=8081

build.gradle file

buildscript {
    repositories {
        //jcenter()
                mavenLocal()
        mavenCentral()
        maven { url "http://repo.spring.io/release" }
        maven { url "http://repo.spring.io/milestone" }
        maven { url "http://repo.spring.io/snapshot" }
    }
    dependencies {
        classpath('org.springframework.boot:spring-boot-gradle-plugin:1.5.1.RELEASE')
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'org.springframework.boot'
apply plugin: 'war'

repositories {
        mavenLocal()
        mavenCentral()
        maven { url "http://repo.spring.io/release" }
        maven { url "http://repo.spring.io/milestone" }
        maven { url "http://repo.spring.io/snapshot" }
        maven { url "https://repository.jboss.org/nexus/content/repositories/releases" }
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencies {
compile("org.springframework.boot:spring-boot-starter")
    compile("org.springframework.boot:spring-boot-starter-web")
    compile("org.springframework.boot:spring-boot-starter-jdbc")
     compile("org.springframework.boot:spring-boot-starter-jersey")
     compile("org.apache.tomcat.embed:tomcat-embed-jasper")
     compile("mysql:mysql-connector-java")
     compile("javax.inject:javax.inject")
     compile("org.springframework.boot:spring-boot")
    testCompile("org.springframework.boot:spring-boot-starter-test")
 compile("org.springframework.boot:spring-boot-devtools")
compile("org.springframework.boot:spring-boot-starter-data-jpa")



}

Error Trace(it includes jersey and servlet related errors as i am hitting DAO through rest call this can be ignored)

2017-02-26 08:30:27.158 ERROR 1076 --- [nio-8081-exec-1] o.s.boot.web.support.ErrorPageFilter     : Forwarding to error page from request [/services/health] due to exception [org.springframework.orm.jpa.JpaSystemException: Could not set field value [2] value by reflection : [class com.dto.Product.productId] setter of com.dto.Product.productId; nested exception is org.hibernate.PropertyAccessException: Could not set field value [2] value by reflection : [class com.dto.Product.productId] setter of com.dto.Product.productId]

javax.servlet.ServletException: org.springframework.orm.jpa.JpaSystemException: Could not set field value [2] value by reflection : [class com.dto.Product.productId] setter of com.dto.Product.productId; nested exception is org.hibernate.PropertyAccessException: Could not set field value [2] value by reflection : [class com.dto.Product.productId] setter of com.dto.Product.productId
    at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:489) ~[jersey-container-servlet-core-2.25.1.jar:na]
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427) ~[jersey-container-servlet-core-2.25.1.jar:na]
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388) ~[jersey-container-servlet-core-2.25.1.jar:na]
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341) ~[jersey-container-servlet-core-2.25.1.jar:na]
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228) ~[jersey-container-servlet-core-2.25.1.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.springframework.boot.web.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:115) [spring-boot-1.5.1.RELEASE.jar:1.5.1.RELEASE]
    at org.springframework.boot.web.support.ErrorPageFilter.access$000(ErrorPageFilter.java:59) [spring-boot-1.5.1.RELEASE.jar:1.5.1.RELEASE]
    at org.springframework.boot.web.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:90) [spring-boot-1.5.1.RELEASE.jar:1.5.1.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.boot.web.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:108) [spring-boot-1.5.1.RELEASE.jar:1.5.1.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_45]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_45]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.11.jar:8.5.11]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_45]
Caused by: org.springframework.orm.jpa.JpaSystemException: Could not set field value [2] value by reflection : [class com.dto.Product.productId] setter of com.dto.Product.productId; nested exception is org.hibernate.PropertyAccessException: Could not set field value [2] value by reflection : [class com.dto.Product.productId] setter of com.dto.Product.productId
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.convertHibernateAccessException(HibernateJpaDialect.java:333) ~[spring-orm-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:241) ~[spring-orm-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.translateExceptionIfPossible(AbstractEntityManagerFactoryBean.java:491) ~[spring-orm-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.dao.support.ChainedPersistenceExceptionTranslator.translateExceptionIfPossible(ChainedPersistenceExceptionTranslator.java:59) ~[spring-tx-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:213) ~[spring-tx-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:147) ~[spring-tx-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99) ~[spring-tx-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282) ~[spring-tx-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) ~[spring-tx-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:656) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at com.example.DAOClass$$EnhancerBySpringCGLIB$$960298ca.saveProduct(<generated>) ~[bin/:na]
    at com.example.HealthController.health(HealthController.java:21) ~[bin/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_45]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_45]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_45]
    at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_45]
    at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:144) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:161) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$TypeOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:205) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:99) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:389) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:347) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:326) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271) ~[jersey-common-2.25.1.jar:na]
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267) ~[jersey-common-2.25.1.jar:na]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315) ~[jersey-common-2.25.1.jar:na]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297) ~[jersey-common-2.25.1.jar:na]
    at org.glassfish.jersey.internal.Errors.process(Errors.java:267) ~[jersey-common-2.25.1.jar:na]
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317) ~[jersey-common-2.25.1.jar:na]
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154) ~[jersey-server-2.25.1.jar:na]
    at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473) ~[jersey-container-servlet-core-2.25.1.jar:na]
    ... 48 common frames omitted
Caused by: org.hibernate.PropertyAccessException: Could not set field value [2] value by reflection : [class com.dto.Product.productId] setter of com.dto.Product.productId
    at org.hibernate.property.access.spi.SetterFieldImpl.set(SetterFieldImpl.java:58) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.tuple.entity.AbstractEntityTuplizer.setIdentifier(AbstractEntityTuplizer.java:260) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.persister.entity.AbstractEntityPersister.setIdentifier(AbstractEntityPersister.java:4617) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:168) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:121) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:679) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:671) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:666) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    at com.example.DAOClass.saveProduct(DAOClass.java:31) ~[bin/:na]
    at com.example.DAOClass$$FastClassBySpringCGLIB$$f5c2d5f7.invoke(<generated>) ~[bin/:na]
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:721) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) ~[spring-aop-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136) ~[spring-tx-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    ... 78 common frames omitted
Caused by: java.lang.IllegalArgumentException: Can not set java.lang.Integer field com.dto.Product.productId to com.dto.Product
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167) ~[na:1.8.0_45]
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171) ~[na:1.8.0_45]
    at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:58) ~[na:1.8.0_45]
    at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:75) ~[na:1.8.0_45]
    at java.lang.reflect.Field.set(Field.java:764) ~[na:1.8.0_45]
    at org.hibernate.property.access.spi.SetterFieldImpl.set(SetterFieldImpl.java:38) ~[hibernate-core-5.0.11.Final.jar:5.0.11.Final]
    ... 96 common frames omitted

above error states that org.hibernate.PropertyAccessException: Could not set field value [2] value by reflection : [class com.dto.Product.productId]

don't know the exact reason.

But i am able get all the details of product table by using HQL and also able to get particular product details by using session.get(Product.class,productId).

while persisting the data i am facing the problem. Everything works fine if i use Hibernate xml mapping.

Facing the same problem for onetomany mapping as well.

adding the product table description image

product table description

Table :

create table PRODUCT ( PRODUCT_ID int not null, PRODUCT_NAME varchar(50), PRICE DECIMAL(5,2), primary key(PRODUCE_ID) );

I went through below sites :

https://hellokoding.com/jpa-one-to-many-relationship-mapping-example-with-spring-boot-hsql/

I want session Factory Object and should perform all the operations through it.

Answer 1

The cause of the exception is

Can not set java.lang.Integer field com.dto.Product.productId to com.dto.Product

Hibernate is trying to set the field Product.productId to a value com.dto.Product, which is something else than an Integer.

This is most likely caused by the 'marksIdGenerator'. Have a look if it is really producing Integer.