Package com.fasterxml.jackson.core

Class ObjectCodec

  • All Implemented Interfaces:
    Versioned
    Direct Known Subclasses:
    ObjectMapper, ObjectReader
    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".

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method 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.
      Use getFactory() instead.
      abstract <T extends TreeNode>
      T      		 readTree​(JsonParser p)
      Method for deserializing JSON content as tree expressed using set of TreeNode instances.
      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<T> valueTypeRef)
      Method to deserialize JSON content into a Java type, reference to which is passed as argument.
      abstract <T> T readValue​(JsonParser p, java.lang.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> java.util.Iterator<T> readValues​(JsonParser p, ResolvedType valueType)
      Method for reading sequence of Objects from parser stream, all with same specified value type.
      abstract <T> java.util.Iterator<T> readValues​(JsonParser p, TypeReference<T> valueTypeRef)
      Method for reading sequence of Objects from parser stream, all with same specified value type.
      abstract <T> java.util.Iterator<T> readValues​(JsonParser p, java.lang.Class<T> valueType)
      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, java.lang.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)
      Method for serializing JSON content from given Tree instance, using specified generator.
      abstract void writeValue​(JsonGenerator gen, java.lang.Object value)
      Method to serialize given Java Object, using generator provided.

      • Methods inherited from class java.lang.Object

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

    • 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
        Returns:
        Version of the component

      • readValue

        public abstract <T> T readValue​(JsonParser p,
                                java.lang.Class<T> valueType)
                         throws java.io.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.

        Type Parameters:
        T - Nominal parameter for target type
        Parameters:
        p - Parser to use for decoding content to bind
        valueType - Java value type to bind content to
        Returns:
        Value deserialized
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • readValue

        public abstract <T> T readValue​(JsonParser p,
                                TypeReference<T> valueTypeRef)
                         throws java.io.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.
        Type Parameters:
        T - Nominal parameter for target type
        Parameters:
        p - Parser to use for decoding content to bind
        valueTypeRef - Java value type to bind content to
        Returns:
        Value deserialized
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • readValue

        public abstract <T> T readValue​(JsonParser p,
                                ResolvedType valueType)
                         throws java.io.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).
        Type Parameters:
        T - Nominal parameter for target type
        Parameters:
        p - Parser to use for decoding content to bind
        valueType - Java value type to bind content to
        Returns:
        Value deserialized
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • readValues

        public abstract <T> java.util.Iterator<T> readValues​(JsonParser p,
                                                     java.lang.Class<T> valueType)
                                              throws java.io.IOException
        Method for reading sequence of Objects from parser stream, all with same specified value type.
        Type Parameters:
        T - Nominal parameter for target type
        Parameters:
        p - Parser to use for decoding content to bind
        valueType - Java value type to bind content to
        Returns:
        Iterator for incrementally deserializing values
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • readValues

        public abstract <T> java.util.Iterator<T> readValues​(JsonParser p,
                                                     TypeReference<T> valueTypeRef)
                                              throws java.io.IOException
        Method for reading sequence of Objects from parser stream, all with same specified value type.
        Type Parameters:
        T - Nominal parameter for target type
        Parameters:
        p - Parser to use for decoding content to bind
        valueTypeRef - Java value type to bind content to
        Returns:
        Iterator for incrementally deserializing values
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • readValues

        public abstract <T> java.util.Iterator<T> readValues​(JsonParser p,
                                                     ResolvedType valueType)
                                              throws java.io.IOException
        Method for reading sequence of Objects from parser stream, all with same specified value type.
        Type Parameters:
        T - Nominal parameter for target type
        Parameters:
        p - Parser to use for decoding content to bind
        valueType - Java value type to bind content to
        Returns:
        Iterator for incrementally deserializing values
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • writeValue

        public abstract void writeValue​(JsonGenerator gen,
                                java.lang.Object value)
                         throws java.io.IOException
        Method to serialize given Java Object, using generator provided.
        Parameters:
        gen - Generator to use for serializing value
        value - Value to serialize
        Throws:
        java.io.IOException - for low-level write issues, or JsonGenerationException for decoding problems

      • readTree

        public abstract <T extends TreeNode> T readTree​(JsonParser p)
                                         throws java.io.IOException
        Method for deserializing 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:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • writeTree

        public abstract void writeTree​(JsonGenerator gen,
                               TreeNode tree)
                        throws java.io.IOException
        Method for serializing JSON content from given Tree instance, using specified generator.
        Specified by:
        writeTree in class TreeCodec
        Parameters:
        gen - Generator to use for serializing value
        tree - Tree to serialize
        Throws:
        java.io.IOException - for low-level write issues, or JsonGenerationException for decoding problems

      • createObjectNode

        public abstract TreeNode createObjectNode()
        Method for construct root level Object nodes for Tree Model instances.
        Specified by:
        createObjectNode in class TreeCodec
        Returns:
        Object node created

      • createArrayNode

        public abstract TreeNode createArrayNode()
        Method for construct root level Array nodes for Tree Model instances.
        Specified by:
        createArrayNode in class TreeCodec
        Returns:
        Array node created

      • 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
        Parameters:
        n - Content to traverse over
        Returns:
        Parser constructed for traversing over contents of specified node

      • treeToValue

        public abstract <T> T treeToValue​(TreeNode n,
                                  java.lang.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.
        Type Parameters:
        T - Nominal parameter for target type
        Parameters:
        n - Tree to convert
        valueType - Java target value type to convert content to
        Returns:
        Converted value instance
        Throws:
        JsonProcessingException - if structural conversion fails

      • getFactory

        public JsonFactory getFactory()
        Accessor for finding underlying data format factory (JsonFactory) codec will use for data binding.
        Returns:
        Underlying JsonFactory instance