com.epimorphics.json

Class JsonUtil

java.lang.Object

com.epimorphics.json.JsonUtil

public class JsonUtil
extends Object

Utilities to make it easier to access JSON data and convert between JSON encodings and plain java encodings.

Author:

Dave Reynolds

Constructor Summary

Constructors

Constructor and Description
JsonUtil()

Method Summary

Modifier and Type	Method and Description
static org.apache.jena.atlas.json.JsonValue	asJson(Object obj) Convert java objects to JSON objects.
static org.apache.jena.atlas.json.JsonObject	emptyObject() Return a new singleton empty object
static Object	fromJson(org.apache.jena.atlas.json.JsonValue jv) Convert a JSON value to a corresponding plain Java value.
static boolean	getBooleanValue(org.apache.jena.atlas.json.JsonObject jo, String field, boolean dflt)
static int	getIntValue(org.apache.jena.atlas.json.JsonObject jo, String field, int dflt)
static long	getLongValue(org.apache.jena.atlas.json.JsonObject jo, String field, long dflt)
static <T> T	getPath(org.apache.jena.atlas.json.JsonValue root, Class<T> target, Object... selectors) Return an element of a JSON structure by following a sequence of object field selectors (strings) or array indexes (integers) and return the java-ized version of the leaf.
static Object	getPath(org.apache.jena.atlas.json.JsonValue root, Object... selectors) Return an element of a JSON structure by following a sequence of object field selectors (strings) or array indexes (integers) and return the java-ized version of the leaf.
static String	getStringValue(org.apache.jena.atlas.json.JsonObject jo, String field)
static String	getStringValue(org.apache.jena.atlas.json.JsonObject jo, String field, String dflt)
static org.apache.jena.atlas.json.JsonValue	loadFromFile(String filename)
static org.apache.jena.atlas.json.JsonObject	makeJson(org.apache.jena.atlas.json.JsonObject base, Object... args) Create a JSON object as a copy of an existing object, with new/replacement key values taken from the args
static org.apache.jena.atlas.json.JsonObject	makeJson(Object... args) Create a simple Json Object.
static org.apache.jena.atlas.json.JsonObject	merge(org.apache.jena.atlas.json.JsonObject base, org.apache.jena.atlas.json.JsonObject extend) Create a new json object by cloning one object and then asserting all values from the second.
static org.apache.jena.atlas.json.JsonObject	mergeInto(org.apache.jena.atlas.json.JsonObject base, org.apache.jena.atlas.json.JsonObject extend) Merge all the extend values into the base object returning the base object, no copy.
static org.apache.jena.atlas.json.JsonArray	readArray(String filename) Parse a JSON or YAML file to an array of json objects, supports multi-document yaml files
static org.apache.jena.atlas.json.JsonArray	readArray(String filename, InputStream is) Parse a JSON or YAML file to an array of json objects, supports multi-document yaml files
static org.apache.jena.atlas.json.JsonObject	readObject(String filename) Parse a JSON or YAML file to a json object.
static org.apache.jena.atlas.json.JsonObject	readObject(String filename, InputStream is) Parse a JSON or YAML file to a json object.

Methods inherited from class java.lang.Object

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

Constructor Detail

JsonUtil

public JsonUtil()

Method Detail

loadFromFile

public static org.apache.jena.atlas.json.JsonValue loadFromFile(String filename)

getStringValue

public static String getStringValue(org.apache.jena.atlas.json.JsonObject jo,
                                    String field)

getStringValue

public static String getStringValue(org.apache.jena.atlas.json.JsonObject jo,
                                    String field,
                                    String dflt)

getIntValue

public static int getIntValue(org.apache.jena.atlas.json.JsonObject jo,
                              String field,
                              int dflt)

getLongValue

public static long getLongValue(org.apache.jena.atlas.json.JsonObject jo,
                                String field,
                                long dflt)

getBooleanValue

public static boolean getBooleanValue(org.apache.jena.atlas.json.JsonObject jo,
                                      String field,
                                      boolean dflt)

asJson

public static org.apache.jena.atlas.json.JsonValue asJson(Object obj)

Convert java objects to JSON objects. Handles strings, numbers, booleans, maps and lists and simple nests thereof. Throws runtime exception if this is not possible.

makeJson

public static org.apache.jena.atlas.json.JsonObject makeJson(Object... args)

Create a simple Json Object.

Parameters:

args - alternating parameter names and parameter values

makeJson

public static org.apache.jena.atlas.json.JsonObject makeJson(org.apache.jena.atlas.json.JsonObject base,
                                                             Object... args)

Create a JSON object as a copy of an existing object, with new/replacement key values taken from the args

Parameters:

base - object to copy, can be null

args - alternating parameter names and parameter values

fromJson

public static Object fromJson(org.apache.jena.atlas.json.JsonValue jv)

Convert a JSON value to a corresponding plain Java value. A near inverse of asJson except that number types might be changed.

getPath

public static Object getPath(org.apache.jena.atlas.json.JsonValue root,
                             Object... selectors)

Return an element of a JSON structure by following a sequence of object field selectors (strings) or array indexes (integers) and return the java-ized version of the leaf. Throws runtime exception if the structure does not match.

getPath

public static <T> T getPath(org.apache.jena.atlas.json.JsonValue root,
                            Class<T> target,
                            Object... selectors)

Return an element of a JSON structure by following a sequence of object field selectors (strings) or array indexes (integers) and return the java-ized version of the leaf. Returns the value as the requested target class if possible. Throws runtime exception if the structure does not match.

emptyObject

public static org.apache.jena.atlas.json.JsonObject emptyObject()

Return a new singleton empty object

merge

public static org.apache.jena.atlas.json.JsonObject merge(org.apache.jena.atlas.json.JsonObject base,
                                                          org.apache.jena.atlas.json.JsonObject extend)

Create a new json object by cloning one object and then asserting all values from the second. Shallow copy only.

mergeInto

public static org.apache.jena.atlas.json.JsonObject mergeInto(org.apache.jena.atlas.json.JsonObject base,
                                                              org.apache.jena.atlas.json.JsonObject extend)

Merge all the extend values into the base object returning the base object, no copy.

readArray

public static org.apache.jena.atlas.json.JsonArray readArray(String filename,
                                                             InputStream is)

Parse a JSON or YAML file to an array of json objects, supports multi-document yaml files

readArray

public static org.apache.jena.atlas.json.JsonArray readArray(String filename)
                                                      throws FileNotFoundException

Parse a JSON or YAML file to an array of json objects, supports multi-document yaml files

Throws:

FileNotFoundException

readObject

public static org.apache.jena.atlas.json.JsonObject readObject(String filename,
                                                               InputStream is)

Parse a JSON or YAML file to a json object.

readObject

public static org.apache.jena.atlas.json.JsonObject readObject(String filename)
                                                        throws FileNotFoundException

Parse a JSON or YAML file to a json object.

Throws:

FileNotFoundException