/*
* © Copyright IBM Corp. 2012-2013
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package com.ibm.commons.util.io.json;
import java.io.Reader;
import java.util.List;
import com.ibm.commons.util.io.json.parser.Json;
/**
* JSON parser.
* <p>
* This class provides some methods for generating parsing JSON text and create
* objects out of it. It uses a factory to deal with the actual object classes.
* </p>
* @ibm-api
*/
public class JsonParser {
/**
* Callback when a stream of json entries is parsed
*/
public static interface ParseCallback {
public void jsonEntry(Object o) throws JsonException;
}
/**
* Check if a string a a valid JSON text.
* @param json the JSON text to check
* @return true if the string is a JSON object
* @throws JsonException
* @ibm-api
*/
public static boolean isJson(String json) {
try {
Json parser = getParser(JsonEmptyFactory.instance,new java.io.StringReader(json));
parser.parseJson();
return true;
} catch(Throwable ex) {
return false;
}
}
/**
* Parse a JSON text and return an object.
* @param factory the object factory
* @param json the JSON text
* @return the object created from the JSON text
* @throws JsonException
* @ibm-api
*/
public static Object fromJson(JsonFactory factory, String json) throws JsonException {
try {
Json parser = getParser(factory,new java.io.StringReader(json));
return parser.parseJson();
} catch(Throwable ex) {
throw new JsonException(ex,"Error when parsing JSON string"); // $NLS-JsonParser.ErrorwhenparsingJSONstring-1$
}
}
/**
* Parse a JSON stream and return an object.
* @param factory the object factory
* @param reader the JSON stream
* @return the object created from the JSON text
* @throws JsonException
* @ibm-api
*/
public static Object fromJson(JsonFactory factory, Reader reader) throws JsonException {
try {
Json parser = getParser(factory,reader);
return parser.parseJson();
} catch(Throwable ex) {
throw new JsonException(ex,"Error when parsing JSON stream"); // $NLS-JsonParser.ErrorwhenparsingJSONstream-1$
}
}
/**
* Parse a JSON stream and add all the entries to a list.
* @param factory the object factory
* @param reader the JSON stream
* @param cb the cllback to call for each entry
* @return the object created from the JSON text
* @throws JsonException
* @ibm-api
*/
public static void fromJson(JsonFactory factory, Reader reader, List<Object> list) throws JsonException {
try {
Json parser = getParser(factory,reader);
parser.parseJsonList(list);
} catch(Throwable ex) {
throw new JsonException(ex,"Error when parsing JSON list");
}
}
/**
* Parse a JSON stream and call a function for each entry.
* @param factory the object factory
* @param reader the JSON stream
* @param cb the cllback to call for each entry
* @return the object created from the JSON text
* @throws JsonException
* @ibm-api
*/
public static void fromJson(JsonFactory factory, Reader reader, ParseCallback cb) throws JsonException {
try {
Json parser = getParser(factory,reader);
parser.parseJsonCallback(cb);
} catch(Throwable ex) {
throw new JsonException(ex,"Error when parsing JSON stream");
}
}
private static Json getParser(JsonFactory factory, Reader r) {
Json parser = new Json(r);
parser.factory = factory;
return parser;
}
}