/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.oltu.commons.json;
import static java.lang.String.format;
import org.json.JSONArray;
import org.json.JSONTokener;
/**
* TODO
*/
public abstract class CustomizableEntityReader<E, B extends CustomizableBuilder<E>> {
private final B builder;
public CustomizableEntityReader(B builder) {
this.builder = builder;
}
protected final B getBuilder() {
return builder;
}
/**
* Method extracted from {@code org.json.JSONObject#JSONObject(JSONTokener)}
*
* @param jsonString
*/
public void read(String jsonString) {
final JSONTokener x = new JSONTokener(jsonString);
char c;
String key;
if (x.nextClean() != '{') {
throw new IllegalArgumentException(format("String '%s' is not a valid JSON object representation, a JSON object text must begin with '{'",
jsonString));
}
for (;;) {
c = x.nextClean();
switch (c) {
case 0:
throw new IllegalArgumentException(format("String '%s' is not a valid JSON object representation, a JSON object text must end with '}'",
jsonString));
case '}':
return;
default:
x.back();
key = x.nextValue().toString();
}
/*
* The key is followed by ':'. We will also tolerate '=' or '=>'.
*/
c = x.nextClean();
if (c == '=') {
if (x.next() != '>') {
x.back();
}
} else if (c != ':') {
throw new IllegalArgumentException(format("String '%s' is not a valid JSON object representation, expected a ':' after the key '%s'",
jsonString, key));
}
Object value = x.nextValue();
// guard from null values
if (value != null) {
if (value instanceof JSONArray) { // only plain simple arrays in this version
JSONArray array = (JSONArray) value;
Object[] values = new Object[array.length()];
for (int i = 0; i < array.length(); i++) {
values[i] = array.get(i);
}
value = values;
}
// if the concrete implementation is not able to handle the property, set the custom field
if (!handleProperty(key, value)) {
builder.setCustomField(key, value);
}
}
/*
* Pairs are separated by ','. We will also tolerate ';'.
*/
switch (x.nextClean()) {
case ';':
case ',':
if (x.nextClean() == '}') {
return;
}
x.back();
break;
case '}':
return;
default:
throw new IllegalArgumentException("Expected a ',' or '}'");
}
}
}
protected abstract <T> boolean handleProperty(String key, T value);
}