/*
* Copyright (C) 2012 Facebook, Inc.
*
* 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.facebook.config;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.regex.Pattern;
/**
* Provides JSON stored in a file
*/
public class FileJSONProvider implements JSONProvider {
private static final Pattern COMMENT_LINE = Pattern.compile("^\\s*//.*");
private final File file;
public FileJSONProvider(File file) {
this.file = file;
}
protected BufferedReader getReader() throws FileNotFoundException {
return new BufferedReader(new FileReader(file));
}
private JSONObject fileToJSON() throws IOException, JSONException {
StringBuilder sb = new StringBuilder(1024);
BufferedReader in = null;
try {
in = getReader();
String line;
while ((line = in.readLine()) != null) {
// skip simple comment lines
if (!COMMENT_LINE.matcher(line).find()) {
sb.append(line);
}
}
} finally {
if (in != null) {
in.close();
}
}
return new JSONObject(sb.toString());
}
@Override
public JSONObject get() throws JSONException {
try {
return fileToJSON();
} catch (IOException e) {
throw new JSONException(e);
}
}
}