org.kopitubruk.util.json

Interface JSONAble

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface JSONAble

This interface specifies a method which implementing objects will use to provide a JSON representation of themselves. When JSONUtil.toJSON(Object, JSONConfig) encounters one of these objects as one of its property values, it will call this method in those objects to convert them to JSON.

This interface includes some default methods, which were introduced in Java 8. If you want to make this library work with Java 7, then change those to regular public interface signatures and comment out the rest of the code for the default methods.

Author:

Bill Davidson

Method Summary

Modifier and Type	Method and Description
default String	toJSON() Convert this object to a string of JSON data.
default String	toJSON(JSONConfig jsonConfig) Convert this object to a string of JSON data.
void	toJSON(JSONConfig jsonConfig, Writer json) Write this object to the given writer as JSON data.
default void	toJSON(Writer json) Write to the given writer as JSON data using all defaults for the configuration.

Method Detail

toJSON

default String toJSON()

Convert this object to a string of JSON data.

This version does not use a JSONConfig and so can break loop detection. In many common cases, that's not a problem and this is just more convenient.

The default implementation calls toJSON(JSONConfig) to actually do the work.

Returns:

A string of JSON data.

toJSON

default String toJSON(JSONConfig jsonConfig)

Convert this object to a string of JSON data.

Implementations which use JSONUtil to generate their JSON should pass the supplied JSONConfig to JSONUtil.toJSON(Object, JSONConfig) or JSONUtil.toJSON(Object, JSONConfig, Writer) in order to preserve data structure loop detection. If this is not done, then loops may not be detected properly.

The default implementation calls toJSON(JSONConfig, Writer) to actually do the work.

Parameters:

jsonConfig - A configuration object to use to optionally set encoding options.

Returns:

A string of JSON data.

toJSON

default void toJSON(Writer json)
             throws IOException

Write to the given writer as JSON data using all defaults for the configuration.

Parameters:

json - json A writer for the output.

Throws:

IOException - If there is an error on output.

toJSON

void toJSON(JSONConfig jsonConfig,
            Writer json)
     throws IOException

Write this object to the given writer as JSON data. This is the one that gets called by JSONUtil's toJSON methods so if you include JSONAbles inside other structures that you will be passing to JSONUtil's toJSON methods then this one really needs to be implemented and not just "stubbed".

Implementations which use JSONUtil to generate their JSON should pass the supplied JSONConfig to JSONUtil.toJSON(Object, JSONConfig) or JSONUtil.toJSON(Object, JSONConfig, Writer) in order to preserve data structure loop detection. If this is not done, then loops may not be detected properly.

Parameters:

jsonConfig - A configuration object to use to optionally set encoding options.

json - A writer for the output.

Throws:

IOException - If there is an error on output.