package com.data2semantics.yasgui.client.tab.results.input;
/*
* #%L
* YASGUI
* %%
* Copyright (C) 2013 Laurens Rietveld
* %%
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* #L%
*/
import com.data2semantics.yasgui.client.View;
import com.data2semantics.yasgui.client.tab.results.ResultContainer.ResultType;
import com.data2semantics.yasgui.shared.exceptions.SparqlEmptyException;
import com.data2semantics.yasgui.shared.exceptions.SparqlParseException;
import com.google.gwt.json.client.JSONArray;
import com.google.gwt.json.client.JSONBoolean;
import com.google.gwt.json.client.JSONObject;
import com.google.gwt.json.client.JSONParser;
import com.google.gwt.json.client.JSONString;
import com.google.gwt.json.client.JSONValue;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;
/**
* Object to parse and validate a sparql json string
*/
public class JsonResults implements SparqlResults{
@SuppressWarnings("unused")
private View view;
private ResultType queryMode;
private boolean booleanResult;
private ArrayList<String> variables = new ArrayList<String>();
/**Bindings are:
"bindings" : [
{
"a" : { ... } ,
"b" : { ... }
} ,
{
"a" : { ... } ,
"b" : { ... }
}
]**/
private ArrayList<HashMap<String, HashMap<String, String>>> bindings = new ArrayList<HashMap<String, HashMap<String, String>>>();
public JsonResults(String jsonString, View view, ResultType queryMode) throws SparqlParseException, SparqlEmptyException {
this.view = view;
this.queryMode = queryMode;
processResults(jsonString);
}
/**
* Main parser method
* @param jsonString Json string to parse
* @throws SparqlParseException When json string is not valid
* @throws SparqlEmptyException When json string is valid, but contains no results
*/
public void processResults(String jsonString) throws SparqlParseException, SparqlEmptyException {
if (jsonString == null || jsonString.length() == 0) {
throw new SparqlParseException("Unable to parse empty JSON string");
}
JSONValue jsonValue = JSONParser.parseStrict(jsonString);
//no need for this anymore, and it can be quite big. Fingers crossed and hope garbage collector deals witht this properly
jsonString = null;
if (jsonValue == null) {
throw new SparqlParseException("Unable to parse query json string");
}
JSONObject queryResult = jsonValue.isObject();
if (queryResult == null) throw new SparqlParseException("Unable to parse query json string");
if (queryMode == ResultType.Table) {
storeVariables(queryResult);
storeBindings(queryResult);
} else if (queryMode == ResultType.Boolean) {
storeBooleanResult(queryResult);
}
}
public ArrayList<String> getVariables() {
return this.variables;
}
private void storeVariables(JSONObject queryResult) throws SparqlParseException, SparqlEmptyException {
JSONObject head = getAsObject(queryResult.get("head"));
JSONArray variables = getAsArray(head, "vars");
if (variables.size() == 0) {
throw new SparqlEmptyException("Vars missing from json object");
}
for (int i = 0; i < variables.size(); i++) {
this.variables.add(variables.get(i).isString().stringValue());
}
}
public ArrayList<HashMap<String, HashMap<String, String>>> getBindings() {
return this.bindings;
}
private void storeBindings(JSONObject queryResult) throws SparqlParseException, SparqlEmptyException {
JSONObject results = getAsObject(queryResult.get("results"));
JSONArray bindingsArray = getAsArray(results, "bindings");
if (bindingsArray.size() == 0) {
throw new SparqlEmptyException("No results");
}
//Loop through binding array
for (int i = 0; i < bindingsArray.size(); i++) {
JSONObject bindingObject = getAsObject(bindingsArray.get(i));
Set<String> keys = bindingObject.keySet();
Iterator<String> keysIterator = keys.iterator();
HashMap<String, HashMap<String, String>> bindingHashMap = new HashMap<String, HashMap<String, String>>();
//get binding into hashmap (binding is: variabled => node-info json object
while (keysIterator.hasNext()) {
String variable = keysIterator.next();
JSONObject node = getAsObject(bindingObject.get(variable));
Set<String> nodeKeys = node.keySet();
Iterator<String> nodeIterator = nodeKeys.iterator();
HashMap<String, String> nodeHashMap = new HashMap<String, String>();
while (nodeIterator.hasNext()) {
String nodeKey = nodeIterator.next();
String nodeValue = node.get(nodeKey).isString().stringValue();
nodeHashMap.put(nodeKey, nodeValue);
}
bindingHashMap.put(variable, nodeHashMap);
}
this.bindings.add(this.bindings.size(), bindingHashMap);
}
}
/**
* Gets JSON value as object, and throws exception when value is null
*
* @param jsonValue
* @return
* @throws SparqlParseException
*/
public JSONObject getAsObject(JSONValue jsonValue) throws SparqlParseException {
if (jsonValue == null) {
throw new SparqlParseException("Unable to get as object");
}
JSONObject result = jsonValue.isObject();
if (result == null) {
throw new SparqlParseException("Unable to get as object");
}
return result;
}
/**
* Gets JSON value as array, and throws exception when value is null
*
* @param jsonValue
* @param message
* @return
* @throws SparqlParseException
*/
public JSONArray getAsArray(JSONObject jsonObject, String key) throws SparqlParseException {
JSONValue jsonValue = jsonObject.get(key);
if (jsonValue == null) {
throw new SparqlParseException("Unable to get " + key + " as array");
}
JSONArray result = jsonValue.isArray();
if (result == null) {
throw new SparqlParseException("Unable to get " + key + " as array");
}
return result;
}
/**
* Gets JSON value as string, and throws exception when value is null
*
* @param jsonValue
* @param message
* @return
* @throws SparqlParseException
*/
public String getAsString(JSONValue jsonValue) throws SparqlParseException {
JSONString jsonString = jsonValue.isString();
if (jsonString == null) {
throw new SparqlParseException("Cannot format value as string");
}
return jsonString.stringValue();
}
public boolean getBooleanResult() {
return booleanResult;
}
private void storeBooleanResult(JSONObject queryResult) {
JSONBoolean jsonBoolean = queryResult.get("boolean").isBoolean();
if (jsonBoolean == null) {
throw new SparqlParseException("Cannot format value as boolean");
}
booleanResult = jsonBoolean.booleanValue();
}
}