[java] Using Java generics for JPA findAll() query with WHERE clause

Hat tip to Adam Bien if you don't want to use createQuery with a String and want type safety:

 @PersistenceContext
 EntityManager em;

 public List<ConfigurationEntry> allEntries() {
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<ConfigurationEntry> cq = cb.createQuery(ConfigurationEntry.class);
        Root<ConfigurationEntry> rootEntry = cq.from(ConfigurationEntry.class);
        CriteriaQuery<ConfigurationEntry> all = cq.select(rootEntry);
        TypedQuery<ConfigurationEntry> allQuery = em.createQuery(all);
        return allQuery.getResultList();
 }

http://www.adam-bien.com/roller/abien/entry/selecting_all_jpa_entities_as

Examples related to java

Under what circumstances can I call findViewById with an Options Menu / Action Bar item? How much should a function trust another function How to implement a simple scenario the OO way Two constructors How do I get some variable from another class in Java? this in equals method How to split a string in two and store it in a field How to do perspective fixing? String index out of range: 4 My eclipse won't open, i download the bundle pack it keeps saying error log

Examples related to generics

Instantiating a generic type Are these methods thread safe? The given key was not present in the dictionary. Which key? Using Java generics for JPA findAll() query with WHERE clause Using Spring RestTemplate in generic method with generic parameter How to create a generic array? Create a List of primitive int? How to have Java method return generic list of any type? Create a new object from type parameter in generic class What is the "proper" way to cast Hibernate Query.list() to List<Type>?

Examples related to jpa

No converter found capable of converting from type to type How does spring.jpa.hibernate.ddl-auto property exactly work in Spring? Deserialize Java 8 LocalDateTime with JacksonMapper Error creating bean with name 'entityManagerFactory' defined in class path resource : Invocation of init method failed How to beautifully update a JPA entity in Spring Data? JPA Hibernate Persistence exception [PersistenceUnit: default] Unable to build Hibernate SessionFactory How to return a custom object from a Spring Data JPA GROUP BY query How to find distinct rows with field in list using JPA and Spring? What is this spring.jpa.open-in-view=true property in Spring Boot? Spring Data JPA and Exists query

Examples related to criteria-api

Using Java generics for JPA findAll() query with WHERE clause JPA & Criteria API - Select only specific columns JPA CriteriaBuilder - How to use "IN" comparison operator JPA 2.0, Criteria API, Subqueries, In Expressions JPA Criteria API - How to add JOIN clause (as general sentence as possible)