com.fasterxml.jackson.core

## Class ObjectCodec

- java.lang.Object
- - com.fasterxml.jackson.core.TreeCodec
  - - com.fasterxml.jackson.core.ObjectCodec

- All Implemented Interfaces:
    Versioned

      public abstract class ObjectCodec
      extends TreeCodec
      implements Versioned

  Abstract class that defines the interface that `JsonParser` and `JsonGenerator` use to serialize and deserialize regular Java objects (POJOs aka Beans).

  The standard implementation of this class is `com.fasterxml.jackson.databind.ObjectMapper`, defined in the "jackson-databind".

- - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `ObjectCodec()`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
    Modifier and Type | Method and Description
    --- | ---
    `abstract TreeNode` | `createArrayNode()` Method for construct root level Array nodes for Tree Model instances.
    `abstract TreeNode` | `createObjectNode()` Method for construct root level Object nodes for Tree Model instances.
    `JsonFactory` | `getFactory()` Accessor for finding underlying data format factory (`JsonFactory`) codec will use for data binding.
    `JsonFactory` | `getJsonFactory()` Deprecated. Since 2.1: Use `getFactory()` instead.
    `abstract <T extends TreeNode> T` | `readTree(JsonParser p)` Method to deserialize JSON content as tree expressed using set of `TreeNode` instances.
    `abstract <T> T` | `readValue(JsonParser p, Class<T> valueType)` Method to deserialize JSON content into a non-container type (it can be an array type, however): typically a bean, array or a wrapper type (like `Boolean`).
    `abstract <T> T` | `readValue(JsonParser p, ResolvedType valueType)` Method to deserialize JSON content into a POJO, type specified with fully resolved type object (so it can be a generic type, including containers like `Collection` and `Map`).
    `abstract <T> T` | `readValue(JsonParser p, TypeReference<?> valueTypeRef)` Method to deserialize JSON content into a Java type, reference to which is passed as argument.
    `abstract <T> Iterator<T>` | `readValues(JsonParser p, Class<T> valueType)` Method for reading sequence of Objects from parser stream, all with same specified value type.
    `abstract <T> Iterator<T>` | `readValues(JsonParser p, ResolvedType valueType)` Method for reading sequence of Objects from parser stream, all with same specified value type.
    `abstract <T> Iterator<T>` | `readValues(JsonParser p, TypeReference<?> valueTypeRef)` Method for reading sequence of Objects from parser stream, all with same specified value type.
    `abstract JsonParser` | `treeAsTokens(TreeNode n)` Method for constructing a `JsonParser` for reading contents of a JSON tree, as if it was external serialized JSON content.
    `abstract <T> T` | `treeToValue(TreeNode n, Class<T> valueType)` Convenience method for converting given JSON tree into instance of specified value type.
    `abstract Version` | `version()` Method called to detect version of the component that implements this interface; returned version should never be null, but may return specific "not available" instance (see `Version` for details).
    `abstract void` | `writeTree(JsonGenerator gen, TreeNode tree)`
    `abstract void` | `writeValue(JsonGenerator gen, Object value)` Method to serialize given Java Object, using generator provided.

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### ObjectCodec

          protected ObjectCodec()

  - ### Method Detail

    - #### version

          public abstract Version version()

      Description copied from interface: `Versioned`
      Method called to detect version of the component that implements this interface; returned version should never be null, but may return specific "not available" instance (see `Version` for details).
      Specified by:
        `version` in interface `Versioned`

    - #### readValue

          public abstract <T> T readValue(JsonParser p,
                                          Class<T> valueType)
                                   throws IOException

      Method to deserialize JSON content into a non-container type (it can be an array type, however): typically a bean, array or a wrapper type (like `Boolean`).

      Note: this method should NOT be used if the result type is a container (`Collection` or `Map`. The reason is that due to type erasure, key and value types can not be introspected when using this method.

      Throws:
        `IOException`

    - #### readValue

          public abstract <T> T readValue(JsonParser p,
                                          TypeReference<?> valueTypeRef)
                                   throws IOException

      Method to deserialize JSON content into a Java type, reference to which is passed as argument. Type is passed using so-called "super type token" and specifically needs to be used if the root type is a parameterized (generic) container type.
      Throws:
        `IOException`

    - #### readValue

          public abstract <T> T readValue(JsonParser p,
                                          ResolvedType valueType)
                                   throws IOException

      Method to deserialize JSON content into a POJO, type specified with fully resolved type object (so it can be a generic type, including containers like `Collection` and `Map`).
      Throws:
        `IOException`

    - #### readValues

          public abstract <T> Iterator<T> readValues(JsonParser p,
                                                     Class<T> valueType)
                                              throws IOException

      Method for reading sequence of Objects from parser stream, all with same specified value type.
      Throws:
        `IOException`

    - #### readValues

          public abstract <T> Iterator<T> readValues(JsonParser p,
                                                     TypeReference<?> valueTypeRef)
                                              throws IOException

      Method for reading sequence of Objects from parser stream, all with same specified value type.
      Throws:
        `IOException`

    - #### readValues

          public abstract <T> Iterator<T> readValues(JsonParser p,
                                                     ResolvedType valueType)
                                              throws IOException

      Method for reading sequence of Objects from parser stream, all with same specified value type.
      Throws:
        `IOException`

    - #### writeValue

          public abstract void writeValue(JsonGenerator gen,
                                          Object value)
                                   throws IOException

      Method to serialize given Java Object, using generator provided.
      Throws:
        `IOException`

    - #### readTree

          public abstract <T extends TreeNode> T readTree(JsonParser p)
                                                   throws IOException

      Method to deserialize JSON content as tree expressed using set of `TreeNode` instances. Returns root of the resulting tree (where root can consist of just a single node if the current event is a value event, not container). Empty or whitespace documents return null.
      Specified by:
        `readTree` in class `TreeCodec`
      Returns:
        next tree from p, or null if empty.
      Throws:
        `IOException`

    - #### writeTree

          public abstract void writeTree(JsonGenerator gen,
                                         TreeNode tree)
                                  throws IOException

      Specified by:
        `writeTree` in class `TreeCodec`
      Throws:
        `IOException`

    - #### createObjectNode

          public abstract TreeNode createObjectNode()

      Method for construct root level Object nodes for Tree Model instances.
      Specified by:
        `createObjectNode` in class `TreeCodec`

    - #### createArrayNode

          public abstract TreeNode createArrayNode()

      Method for construct root level Array nodes for Tree Model instances.
      Specified by:
        `createArrayNode` in class `TreeCodec`

    - #### treeAsTokens

          public abstract JsonParser treeAsTokens(TreeNode n)

      Method for constructing a `JsonParser` for reading contents of a JSON tree, as if it was external serialized JSON content.
      Specified by:
        `treeAsTokens` in class `TreeCodec`

    - #### treeToValue

          public abstract <T> T treeToValue(TreeNode n,
                                            Class<T> valueType)
                                     throws JsonProcessingException

      Convenience method for converting given JSON tree into instance of specified value type. This is equivalent to first constructing a `JsonParser` to iterate over contents of the tree, and using that parser for data binding.
      Throws:
        `JsonProcessingException`

    - #### getJsonFactory

          @Deprecated
          public JsonFactory getJsonFactory()

      Deprecated. Since 2.1: Use `getFactory()` instead.

    - #### getFactory

          public JsonFactory getFactory()

      Accessor for finding underlying data format factory (`JsonFactory`) codec will use for data binding.
      Since:
        2.1

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