Class Expressions

java.lang.Object
org.springframework.data.jpa.criteria.Expressions
public abstract class Expressions extends Object
Utility methods to resolve JPA Criteria API objects using Spring Data's type-safe property references. These helper methods obtain Criteria API objects using TypedPropertyPath and PropertyReference to resolve property expressions and joins.

The class is intended for concise, type-aware criteria construction through a type-safe DSL where property references are preferred over string-based navigation.

Example: 

Root<User> root = criteriaQuery.from(User.class);

Expression<User> expr = Expressions.get(root, User::getManager);

Join<User, Address> join = Expressions.join(root, JoinType.INNER, j -> j.join(User::getAddress));
Since:
4.1
Author:
Mark Paluch
See Also:

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    Expressions.Fetcher<T>
    Strategy interface used by fetch(From, PropertyReference) to obtain fetch joins using property references.
    static interface 
    Expressions.Joiner<T>
    Strategy interface used by join(From, PropertyReference) to obtain joins using property references.

  • Method Summary

    Modifier and Type
    Method
    Description
    static <T, F extends jakarta.persistence.criteria.Fetch<?,?>>
    F
    fetch(jakarta.persistence.criteria.From<?,T> from, jakarta.persistence.criteria.JoinType joinType, Function<Expressions.Fetcher<T>, F> function)
    Create a fetch join considering JoinType using the given fetcher function allowing to express fetches using property references.
    static <T,P> jakarta.persistence.criteria.Fetch<T,P>
    fetch(jakarta.persistence.criteria.From<?,T> from, PropertyReference<T,P> property)
    Create a fetch join using the given property.
    static <T,P> jakarta.persistence.criteria.Expression<P>
    get(jakarta.persistence.criteria.From<?,T> from, TypedPropertyPath<T,P> property)
    Resolve an Expression for the given property path.
    static <T, J extends jakarta.persistence.criteria.Join<?,?>>
    J
    join(jakarta.persistence.criteria.From<?,T> from, jakarta.persistence.criteria.JoinType joinType, Function<Expressions.Joiner<T>, J> function)
    Create a Join considering JoinType using the given joiner function allowing to express joins using property references.
    static <T,P> jakarta.persistence.criteria.Join<T,P>
    join(jakarta.persistence.criteria.From<?,T> from, PropertyReference<T,P> property)
    Create a Join using the given property.
    static <T,P> jakarta.persistence.criteria.Path<P>
    path(jakarta.persistence.criteria.Path<T> from, TypedPropertyPath<T,P> property)
    Resolve a Path for the given property path.
    static <T> List<jakarta.persistence.criteria.Selection<?>>
    select(jakarta.persistence.criteria.From<?,T> from, TypedPropertyPath<T,?>... properties)
    Create a list of selection objects for the given property paths.
    static <T,P> jakarta.persistence.criteria.Selection<P>
    select(jakarta.persistence.criteria.From<?,T> from, TypedPropertyPath<T,P> property)
    Create a Selection for the given property path.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • path

      public static <T,P> jakarta.persistence.criteria.Path<P> path(jakarta.persistence.criteria.Path<T> from, TypedPropertyPath<T,P> property)
      Resolve a Path for the given property path.

      The resulting path can be used in predicates. In case of a From path, Expression resolution navigates joins as necessary.

      Parameters:
      from - the entity or attribute path start from.
      property - property path to navigate.
      Returns:
      the resolved path.

    • get

      public static <T,P> jakarta.persistence.criteria.Expression<P> get(jakarta.persistence.criteria.From<?,T> from, TypedPropertyPath<T,P> property)
      Resolve an Expression for the given property path.

      The resulting expression can be used in predicates. Expression resolution navigates joins as necessary.

      Parameters:
      from - the root or join to start from.
      property - property path to navigate.
      Returns:
      the resolved expression.

    • select

      public static <T,P> jakarta.persistence.criteria.Selection<P> select(jakarta.persistence.criteria.From<?,T> from, TypedPropertyPath<T,P> property)
      Create a Selection for the given property path.

      The resulting object can be used in the selection, joined paths consider outer joins as needed.

      Parameters:
      from - the root or join to start from.
      property - property path to navigate.
      Returns:
      the selection.

    • select

      @SafeVarargs public static <T> List<jakarta.persistence.criteria.Selection<?>> select(jakarta.persistence.criteria.From<?,T> from, TypedPropertyPath<T,?>... properties)
      Create a list of selection objects for the given property paths.

      The resulting objects can be used in the selection, joined paths consider outer joins as needed.

      Parameters:
      from - the root or join to start from.
      properties - property path to navigate.
      Returns:
      the selection.

    • join

      public static <T,P> jakarta.persistence.criteria.Join<T,P> join(jakarta.persistence.criteria.From<?,T> from, PropertyReference<T,P> property)
      Create a Join using the given property.
      Parameters:
      from - the root or join to start from.
      property - property reference to navigate.
      Returns:
      the resolved join.
      See Also:
      • From.join(String)

    • join

      public static <T, J extends jakarta.persistence.criteria.Join<?,?>> J join(jakarta.persistence.criteria.From<?,T> from, jakarta.persistence.criteria.JoinType joinType, Function<Expressions.Joiner<T>, J> function)
      Create a Join considering JoinType using the given joiner function allowing to express joins using property references.
      Parameters:
      from - the root or join to start from.
      joinType - the join type.
      function - joiner function.
      Returns:
      the resolved join.
      See Also:
      • From.join(String, JoinType)

    • fetch

      public static <T,P> jakarta.persistence.criteria.Fetch<T,P> fetch(jakarta.persistence.criteria.From<?,T> from, PropertyReference<T,P> property)
      Create a fetch join using the given property.
      Parameters:
      from - the root or join to start from.
      property - property reference to navigate.
      Returns:
      the resolved fetch.
      See Also:
      • FetchParent.fetch(String)

    • fetch

      public static <T, F extends jakarta.persistence.criteria.Fetch<?,?>> F fetch(jakarta.persistence.criteria.From<?,T> from, jakarta.persistence.criteria.JoinType joinType, Function<Expressions.Fetcher<T>, F> function)
      Create a fetch join considering JoinType using the given fetcher function allowing to express fetches using property references.
      Parameters:
      from - the root or join to start from.
      joinType - the join type.
      function - fetcher function.
      Returns:
      the resolved fetch.
      See Also:
      • FetchParent.fetch(String, JoinType)