Package com.github.mhewedy.expressions

Class Expressions

java.lang.Object
java.util.AbstractMap<K,V>
java.util.HashMap<String,Object>
com.github.mhewedy.expressions.Expressions
All Implemented Interfaces:
Serializable, Cloneable, Map<String,Object>
public class Expressions extends HashMap<String,Object>
Represents Group of expression using mongodb query api.

Example: 

 {
     "status": "A",
     "$or": [{ "qty": { "$lt": 30 } }, { "item": { "$in": ["A", "D"] } }]
 }

Support a list of Operators defined in Operator.

See Also:

  • Constructor Details

    • Expressions

      public Expressions()

  • Method Details

    • or

      public Expressions or(Expression expression)
      Create a new $or expression on the root, then adds to it the current expressions attached at the root and the expression passes as parameter.

      Example: Suppose we have the following expression as json: 

       {"firstName": "ali"}

      Then we added the following: 

        expressions.or(Expression.and(
          Expression.of("lastName", Operator.$eq, "ibrahim"),
          Expression.of("age", Operator.$gte, 10)
  ));
      Then the output could be represented as: 
       {
     "$or": [
          {"firstName": "ali"},
          {
              "$and": [
                  {"lastName": "ibrahim"},
                  {"age": {"$gte": 10}},
              ]
          }
     ]
 }
      Or in sql as: 
        where firstName = "ali" or lastName = "ibrahim" and age >= 10

    • and

      public Expressions and(Expression expression)
      Add the parameter expression to the list of expression in the expressions object.

      Example: Suppose we have the following expression as json: 

       {"firstName": "ali"}

      Then we added the following: 

        expressions.and(Expression.of("birthDate", Operator.$gt, "1980-10-10"));
  expressions.and(Expression.or(
      Expression.of("lastName", Operator.$eq, "ibrahim"),
      Expression.of("age", Operator.$in, 10, 30)
  ));
      Then the output could be represented as: 
       {
     "firstName": "ali",
     "birthDate": {"$gt": "1980-10-10"},
     "$or": [
          {"lastName": "ibrahim"},
          {"age": {"$in": [10, 30]}}
     ]
 }
      Or in sql as: 
       where firstName = "ali" and birthDate > "1980-10-10"
     and (lastName = "ibrahim" or age in (10, 30) )

    • getSpecification

      public <T> org.springframework.data.jpa.domain.Specification<T> getSpecification()

    • extractFields

      public static List<String> extractFields(Map<String,Object> expressions)
      Extracts all the field names (keys) from the current Expressions object, including nested fields within `$and` and `$or` compound operators.

      This method traverses the structure of the Expressions object recursively. If a compound operator (`$and` or `$or`) is encountered, it extracts fields from all nested expressions.

      Example: Given the following Expressions structure: 

       {
     "firstName": "John",
     "$or": [
         {"lastName": "Doe"},
         {"age": {"$gt": 30}}
     ]
 }
      The resulting list of fields will be: 
       ["firstName", "lastName", "age"]
      Returns:
      a list of field names present in the current Expressions object, including nested fields.