org.jooq.impl.JSONReader Maven / Gradle / Ivy
/**
* Copyright (c) 2009-2014, Data Geekery GmbH (http://www.datageekery.com)
* All rights reserved.
*
* This work is dual-licensed
* - under the Apache Software License 2.0 (the "ASL")
* - under the jOOQ License and Maintenance Agreement (the "jOOQ License")
* =============================================================================
* You may choose which license applies to you:
*
* - If you're using this work with Open Source databases, you may choose
* either ASL or jOOQ License.
* - If you're using this work with at least one commercial database, you must
* choose jOOQ License
*
* For more information, please visit http://www.jooq.org/licenses
*
* Apache Software License 2.0:
* -----------------------------------------------------------------------------
* 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.
*
* jOOQ License and Maintenance Agreement:
* -----------------------------------------------------------------------------
* Data Geekery grants the Customer the non-exclusive, timely limited and
* non-transferable license to install and use the Software under the terms of
* the jOOQ License and Maintenance Agreement.
*
* This library is distributed with a LIMITED WARRANTY. See the jOOQ License
* and Maintenance Agreement for more details: http://www.jooq.org/licensing
*/
package org.jooq.impl;
import java.io.BufferedReader;
import java.io.Closeable;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import org.jooq.tools.json.ContainerFactory;
import org.jooq.tools.json.JSONParser;
import org.jooq.tools.json.ParseException;
/**
* A very simple JSON reader based on Simple JSON.
*
* @author Johannes Bühler
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
class JSONReader implements Closeable {
private final BufferedReader br;
private final JSONParser parser;
private String[] fieldMetaData;
private List records;
public JSONReader(Reader reader) {
this.br = new BufferedReader(reader);
this.parser = new JSONParser();
}
public List readAll() throws IOException {
if (this.records != null) {
return this.records;
}
try {
LinkedHashMap jsonRoot = getJsonRoot();
readFields(jsonRoot);
records = readRecords(jsonRoot);
}
catch (ParseException ex) {
throw new RuntimeException(ex);
}
return records;
}
public String[] getFields() throws IOException {
if (fieldMetaData == null) {
readAll();
}
return fieldMetaData;
}
@Override
public void close() throws IOException {
br.close();
}
private List readRecords(LinkedHashMap jsonRoot) {
LinkedList jsonRecords = (LinkedList) jsonRoot.get("records");
records = new ArrayList();
for (Object record : jsonRecords) {
LinkedList values = (LinkedList) record;
List v = new ArrayList();
for (Object value : values) {
String asString = value == null ? null : String.valueOf(value);
v.add(asString);
}
records.add(v.toArray(new String[v.size()]));
}
return records;
}
private LinkedHashMap getJsonRoot() throws IOException, ParseException {
Object parse = parser.parse(br, new ContainerFactory() {
@Override
public LinkedHashMap createObjectContainer() {
return new LinkedHashMap();
}
@Override
public List createArrayContainer() {
return new LinkedList();
}
});
return (LinkedHashMap) parse;
}
private void readFields(LinkedHashMap jsonRoot) {
if (fieldMetaData != null) {
return;
}
LinkedList fieldEntries = (LinkedList) jsonRoot.get("fields");
fieldMetaData = new String[fieldEntries.size()];
int i = 0;
for (Object key : fieldEntries) {
fieldMetaData[i] = (String) ((LinkedHashMap) key).get("name");
i++;
}
}
}