Package com.cedarsoftware.io

Class JsonIo.JavaObjectBuilder

java.lang.Object
com.cedarsoftware.io.JsonIo.JavaObjectBuilder
Enclosing class:
JsonIo
public static final class JsonIo.JavaObjectBuilder extends Object
Builder for converting a JsonObject (Map representation) to fully resolved Java objects.

This builder completes the conversion process started by JsonIo.toJava(JsonObject, ReadOptions). It provides methods to specify the target type for the conversion from the intermediate JsonObject representation to fully resolved Java objects.

  • Method Details

    • asClass

      public <T> T asClass(Class<T> clazz)
      Completes the conversion by specifying a target class.

      This method converts the JsonObject (Map representation) into an instance of the specified class. This is useful when you have a JsonObject obtained from a previous parsing step (using ReadOptions.returnAsJsonObjects()) and want to convert it to a concrete Java object.

      This method is suitable for converting to:

      • Concrete Java classes (e.g., Person.class)
      • Primitive wrapper classes (e.g., Integer.class)
      • Interface types like Map.class or List.class (which will use appropriate implementations)

      For generic types like List<Person>, use the asType(TypeHolder) method instead.

      Example:

       // First parse JSON to a Map representation
 ReadOptions mapOptions = new ReadOptionsBuilder()
                              .returnAsJsonObjects()
                              .build();
 Map<String, Object> jsonMap = JsonIo.toJava(jsonString, mapOptions).asClass(Map.class);

 // Modify the map
 jsonMap.put("age", 31);

 // Then convert to a Java object
 Person person = JsonIo.toJava(jsonMap, readOptions).asClass(Person.class);
      Type Parameters:
      T - the type to convert the JsonObject to
      Parameters:
      clazz - the target class; if null, the type will be inferred from the JsonObject
      Returns:
      an instance of the specified class populated from the JsonObject

    • asType

      public <T> T asType(TypeHolder<T> typeHolder)
      Completes the conversion by specifying a generic type.

      This method is particularly useful for handling generic types like List<Person> or Map<String, List<Integer>>, where the full type information cannot be expressed with a simple Class object.

      The TypeHolder captures the complete generic type information at compile time, allowing JsonIo to properly handle the generics during conversion.

      Example:

       // First parse JSON to a Map representation
 ReadOptions mapOptions = new ReadOptionsBuilder()
                              .returnAsJsonObjects()
                              .build();
 Map<String, Object> jsonMap = JsonIo.toJava(jsonString, mapOptions).asClass(Map.class);

 // Then convert to a generic collection
 List<Person> people = JsonIo.toJava(jsonMap, readOptions)
                             .asType(new TypeHolder<List<Person>>(){});
      Type Parameters:
      T - the type to convert the JsonObject to
      Parameters:
      typeHolder - a TypeHolder instance capturing the full generic type. It can be null, and JsonIo will do it's best to infer type's/classes, though we recommend passing a Type.
      Returns:
      an object of the specified type populated from the JsonObject