I'm trying to create custom bean validation using annotations and ConstraintValidator interface. The purpose is to make model's name unique. I don't know why, but when I'm submitting form in order to add a product NullPointerException is thrown.
java.lang.NullPointerException
pl.dsdev.validator.UniqueNameValidator.isValid(UniqueNameValidator.java:20)
Model class:
@Entity
public class Product {
@Id
@GeneratedValue
private long id;
@NotNull(message = "Name is required")
@Size.List({@Size(min = 3, message = "must be longer than {min} characters"), @Size(max = 25, message = "must be shorter than {max} characters")})
@UniqueName(message = "This name is used by another product.")
private String name;
Annotation interface:
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = UniqueNameValidator.class)
public @interface UniqueName {
String message() default "";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
Implementation of ConstraintValidator:
public class UniqueNameValidator implements ConstraintValidator<UniqueName, String> {
@Autowired
private ProductService productService;
public void initialize(UniqueName uniqueName) {
}
public boolean isValid(String name, ConstraintValidatorContext constraintValidatorContext) {
return productService.findByName(name)==null;
}
public ProductService getProductService() {
return productService;
}
public void setProductService(ProductService productService) {
this.productService = productService;
}
}
My root-context.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<context:component-scan base-package="pl.dsdev" />
<mvc:annotation-driven />
<!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/springbaza" />
<property name="username" value="tutorial" />
<property name="password" value="password" />
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="pl.dsdev.model" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>
<property name="jpaProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">create</prop>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<tx:annotation-driven />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<bean id="persistenceExceptionTranslationPostProcessor" class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="validation"/>
</bean>
<bean id="validator"
class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"/>
