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A collection of basic java utility classes that provide basic features for a standalone/simple JEE application. Backed by a Cassandra, MySQL, or SQLite database, it provides, web page templates, user and group management, and a searchable online audit log of all user activity.
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/*
 This is free and unencumbered software released into the public domain.

 Anyone is free to copy, modify, publish, use, compile, sell, or
 distribute this software, either in source code form or as a compiled
 binary, for any purpose, commercial or non-commercial, and by any
 means.

 In jurisdictions that recognize copyright laws, the author or authors
 of this software dedicate any and all copyright interest in the
 software to the public domain. We make this dedication for the benefit
 of the public at large and to the detriment of our heirs and
 successors. We intend this dedication to be an overt act of
 relinquishment in perpetuity of all present and future rights to this
 software under copyright law.

 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 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.
 */
package base.json;

import java.io.BufferedReader;
import java.io.CharArrayReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;

/**
 * Lightweight utility to convert a JSON string into its basic Java
 * data type equivalent.
 */
public class JsonParser {

	private static final int MAX_TOKEN_LENGTH = 1024*200;

	private List tokens;
	private BufferedReader stream;
	int tokenindex;

	public JsonParser(String jsonString) throws IOException {
		stream = new BufferedReader(new CharArrayReader(jsonString.toCharArray()));
		tokens = new ArrayList();
	}

	public JsonParser(BufferedReader in) {
		tokens = new ArrayList();
		stream = in;
	}

	private Integer wasPutBack;

	private int streamNext() throws IOException {
		if(wasPutBack != null) {
			int i = wasPutBack;
			wasPutBack = null;
			return i;
		}
		return stream.read();
	}

	private void streamPutBack(int i) {
		if(wasPutBack != null) {
			throw new IllegalStateException("Cant put back more than one character");
		}
		wasPutBack = i;
	}

	/**
	 * Reads a JSON array or dictionary.
	 *
	 * @return Either a List, Map, or NULL if a problem occured.
	 * @throws IOException Error occured reading stream.
	 */
	public Object parse() throws IOException {
		tokenindex = 0;

		String token = null;
		while((token = getToken()) != null) {
			tokens.add(token);
		}

		// If no tokens were found, null must be returned.
		if(tokens.size() == 0) {
			return null;
		}

		if(peekToken().equals("{")) {
			return getDictionary();
		}
		if(peekToken().equals("[")) {
			return getArray();
		}

		return null;
	}

	/**
	 * state table:
	 *   1 = no state
	 *   2 = string
	 *   3 = string escape sequence
	 *   4 = true, false or null
	 */
	private String getToken() throws IOException {
		int tokenlength = 0;
		char[] token = new char[MAX_TOKEN_LENGTH];
		int state = 1;

		while(true) {
			int i = streamNext();
			if(i == -1) {
				if(tokenlength == 0) {
					return null;
				}
				return String.copyValueOf(token, 0, tokenlength);
			}
			char c = (char)i;

			switch(state) {
			case 1 :
				if(c == ' ' || c == '\t' || c == '\n' || c == '\r') {
					continue;
				}
				if(c == '{' || c == '}' || c == '[' || c == ']' || c == ',' || c == ':') {
					return ""+c;
				}
				if(c == '"') {
					state = 2;
					continue;
				}
				if(c == 't' || c == 'f' || c == 'n') {
					state = 4;
					token[tokenlength] = c;
					tokenlength++;
					continue;
				}
				if(c >= '0' && c <= '9') {
					state = 5;
					token[tokenlength] = c;
					tokenlength++;
					continue;
				}
				throw new IllegalArgumentException("Unexpected character: " + c);
			case 2 :
				if(c == '"') {
					return String.copyValueOf(token, 0, tokenlength);
				}
				if(tokenlength == MAX_TOKEN_LENGTH) {
					throw new IllegalArgumentException("Token exceeded maximum length of " + MAX_TOKEN_LENGTH + " characters.");
				}
				if(c == '\\') {
					state = 3;
					break;
				}
				token[tokenlength] = c;
				tokenlength++;
				break;
			case 3 :
				if(c == 'n') {
					token[tokenlength] = '\n';
					tokenlength++;
					state = 2;
				} else if(c == '"') {
					token[tokenlength] = '"';
					tokenlength++;
					state = 2;
				} else if(c == '\\') {
					token[tokenlength] = '\\';
					tokenlength++;
					state = 2;
				} else if(c == '/') {
					token[tokenlength] = '/';
					tokenlength++;
					state = 2;
				} else if(c == 'b') {
					token[tokenlength] = '\b';
					tokenlength++;
					state = 2;
				} else if(c == 'f') {
					token[tokenlength] = '\f';
					tokenlength++;
					state = 2;
				} else if(c == 'r') {
					token[tokenlength] = '\r';
					tokenlength++;
					state = 2;
				} else if(c == 't') {
					token[tokenlength] = '\t';
					tokenlength++;
					state = 2;
				} else {
					token[tokenlength] = '\\';
					tokenlength++;
					if(tokenlength == MAX_TOKEN_LENGTH) {
						throw new IllegalArgumentException("Token exceeded maximum length of " + MAX_TOKEN_LENGTH + " characters.");
					}
					token[tokenlength] = c;
					tokenlength++;
					state = 2;
				}
				break;
			case 4 :
				if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
					token[tokenlength] = c;
					tokenlength++;
				}
				String value = String.copyValueOf(token, 0, tokenlength).toLowerCase();
				if(value.equals("true")) {
					tokenlength = 0;
					state = 0;
					return "true";
				}
				if(value.equals("false")) {
					tokenlength = 0;
					state = 0;
					return "false";
				}
				if(value.equals("null")) {
					tokenlength = 0;
					state = 0;
					return "null";
				}
				if(value.length() >= 6) {
					throw new IOException("Invalid JSON, unescaped text in JSON data: " + value);
				}
				break;
			case 5 :
				if(c >= '0' && c <= '9') {
					token[tokenlength] = c;
					tokenlength++;
				} else {
					streamPutBack(i);
					String number = String.copyValueOf(token, 0, tokenlength).toLowerCase();
					tokenlength = 0;
					state = 0;
					return number;
				}
				break;
			default:
				throw new IOException("Unexpected character in JSON file");
			}
		}

		//TODO: huh?
		//if(index!=string.length()) System.out.println("Unexpected character in JSON file");
		//return null;
	}

	private Map getDictionary() {
		if(!peekToken().equals("{")) {
			throw new IllegalArgumentException("Expecting { but found " + peekToken());
		}
		nextToken();
		Map dictionary = new Hashtable<>();

		while(true) {

			// Get name
			String name = nextToken();
			if(name == null) {
				throw new IllegalArgumentException("Expecting name, but found nothing");
			}
			if(name.equals("}")) {
				break;
			}

			// Get separator
			String colon = nextToken();
			if(colon == null) {
				throw new IllegalArgumentException("Expecting colon, but found nothing");
			}
			if(!colon.equals(":")) {
				throw new IllegalArgumentException("Expecting colon, but found nothing");
			}

			// Get value
			String peek = peekToken();
			if(peek.equals("[")) {
				dictionary.put(name, getArray());
			} else {
				if(peek.equals("{")) {
					dictionary.put(name, getDictionary());
				} else {
					dictionary.put(name, nextToken());
				}
			}

			if(peekToken().equals(",")) {
				nextToken();
			} else if(!peekToken().equals("}")) {
				throw new IllegalArgumentException("Expecting , or } but saw " + peekToken());
			}
		}

		return dictionary;
	}

	private String nextToken() {
		if(tokenindex == tokens.size()) {
			return null;
		}
		String token = tokens.get(tokenindex);
		tokenindex++;
		return token;
	}

	private String peekToken() {
		if(tokenindex >= tokens.size()) {
			return null;
		}
		return tokens.get(tokenindex);
	}

	private List