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/*
* Copyright 2008-present MongoDB, 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.mongodb.util;
import org.bson.BSONCallback;
/**
* Helper methods for JSON serialization and de-serialization
*
* @see org.bson.json.JsonReader
* @see org.bson.json.JsonWriter
* @see com.mongodb.BasicDBObject#toJson()
* @see com.mongodb.BasicDBObject#parse(String)
*
* @deprecated This class has been superseded by to toJson and parse methods on BasicDBObject
*/
@Deprecated
@SuppressWarnings("deprecation")
public class JSON {
/**
* Serializes an object into its JSON form.
*
* This method delegates serialization to {@code JSONSerializers.getLegacy}
*
* @param object object to serialize
* @return String containing JSON form of the object
* @see JSONSerializers#getLegacy()
*/
public static String serialize(final Object object) {
StringBuilder buf = new StringBuilder();
serialize(object, buf);
return buf.toString();
}
/**
* Serializes an object into its JSON form.
*
* This method delegates serialization to {@code JSONSerializers.getLegacy}
*
* @param object object to serialize
* @param buf StringBuilder containing the JSON representation under construction
* @see JSONSerializers#getLegacy()
*/
public static void serialize(final Object object, final StringBuilder buf) {
JSONSerializers.getLegacy().serialize(object, buf);
}
/**
* Parses a JSON string and returns a corresponding Java object. The returned value is either a {@link com.mongodb.DBObject DBObject}
* (if the string is a JSON object or array), or a boxed primitive value according to the following mapping:
*
* - {@code java.lang.Boolean} for {@code true} or {@code false}
* - {@code java.lang.Integer} for integers between Integer.MIN_VALUE and Integer.MAX_VALUE
* - {@code java.lang.Long} for integers outside of this range
* - {@code java.lang.Double} for floating point numbers
*
* If the parameter is a string that contains a single-quoted or double-quoted string, it is returned as an unquoted {@code
* java.lang.String}. Parses a JSON string representing a JSON value
*
* @param jsonString the string to parse
* @return a Java object representing the JSON data
* @throws JSONParseException if jsonString is not valid JSON
*/
public static Object parse(final String jsonString) {
return parse(jsonString, null);
}
/**
* Parses a JSON string and constructs a corresponding Java object by calling the methods of a {@link org.bson.BSONCallback
* BSONCallback} during parsing. If the callback {@code c} is null, this method is equivalent to {@link JSON#parse(String)
* parse(String)}.
*
* @param s the string to parse
* @param c the BSONCallback to call during parsing
* @return a Java object representing the JSON data
* @throws JSONParseException if s is not valid JSON
*/
public static Object parse(final String s, final BSONCallback c) {
if (s == null || (s.trim()).equals("")) {
return null;
}
JSONParser p = new JSONParser(s, c);
return p.parse();
}
static void string(final StringBuilder a, final String s) {
a.append("\"");
for (int i = 0; i < s.length(); ++i) {
char c = s.charAt(i);
if (c == '\\') {
a.append("\\\\");
} else if (c == '"') {
a.append("\\\"");
} else if (c == '\n') {
a.append("\\n");
} else if (c == '\r') {
a.append("\\r");
} else if (c == '\t') {
a.append("\\t");
} else if (c == '\b') {
a.append("\\b");
} else if (c < 32) {
continue;
} else {
a.append(c);
}
}
a.append("\"");
}
}
/**
* Parser for JSON objects.
*
* Supports all types described at www.json.org, except for numbers with "e" or "E" in them.
*/
class JSONParser {
final String s;
int pos = 0;
final BSONCallback _callback;
JSONParser(final String s) {
this(s, null);
}
@SuppressWarnings("deprecation")
JSONParser(final String s, final BSONCallback callback) {
this.s = s;
_callback = (callback == null) ? new JSONCallback() : callback;
}
/**
* Parse an unknown type.
*
* @return Object the next item
* @throws JSONParseException if invalid JSON is found
*/
public Object parse() {
return parse(null);
}
/**
* Parse an unknown type.
*
* @return Object the next item
* @throws JSONParseException if invalid JSON is found
*/
protected Object parse(final String name) {
Object value = null;
char current = get();
switch (current) {
// null
case 'n':
read('n');
read('u');
read('l');
read('l');
value = null;
break;
// NaN
case 'N':
read('N');
read('a');
read('N');
value = Double.NaN;
break;
// true
case 't':
read('t');
read('r');
read('u');
read('e');
value = true;
break;
// false
case 'f':
read('f');
read('a');
read('l');
read('s');
read('e');
value = false;
break;
// string
case '\'':
case '\"':
value = parseString(true);
break;
// number
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
case '+':
case '-':
value = parseNumber();
break;
// array
case '[':
value = parseArray(name);
break;
// object
case '{':
value = parseObject(name);
break;
default:
throw new JSONParseException(s, pos);
}
return value;
}
/**
* Parses an object for the form {} and { members }.
*
* @return DBObject the next object
* @throws JSONParseException if invalid JSON is found
*/
public Object parseObject() {
return parseObject(null);
}
/**
* Parses an object for the form {} and { members }.
*
* @return DBObject the next object
* @throws JSONParseException if invalid JSON is found
*/
protected Object parseObject(final String name) {
if (name != null) {
_callback.objectStart(name);
} else {
_callback.objectStart();
}
read('{');
char current = get();
while (get() != '}') {
String key = parseString(false);
read(':');
Object value = parse(key);
doCallback(key, value);
if ((current = get()) == ',') {
read(',');
} else {
break;
}
}
read('}');
return _callback.objectDone();
}
protected void doCallback(final String name, final Object value) {
if (value == null) {
_callback.gotNull(name);
} else if (value instanceof String) {
_callback.gotString(name, (String) value);
} else if (value instanceof Boolean) {
_callback.gotBoolean(name, (Boolean) value);
} else if (value instanceof Integer) {
_callback.gotInt(name, (Integer) value);
} else if (value instanceof Long) {
_callback.gotLong(name, (Long) value);
} else if (value instanceof Double) {
_callback.gotDouble(name, (Double) value);
}
}
/**
* Read the current character, making sure that it is the expected character. Advances the pointer to the next character.
*
* @param ch the character expected
* @throws JSONParseException if the current character does not match the given character
*/
public void read(final char ch) {
if (!check(ch)) {
throw new JSONParseException(s, pos);
}
pos++;
}
public char read() {
if (pos >= s.length()) {
throw new IllegalStateException("string done");
}
return s.charAt(pos++);
}
/**
* Read the current character, making sure that it is a hexidecimal character.
*
* @throws JSONParseException if the current character is not a hexidecimal character
*/
public void readHex() {
if (pos < s.length()
&& ((s.charAt(pos) >= '0' && s.charAt(pos) <= '9')
|| (s.charAt(pos) >= 'A' && s.charAt(pos) <= 'F')
|| (s.charAt(pos) >= 'a' && s.charAt(pos) <= 'f'))) {
pos++;
} else {
throw new JSONParseException(s, pos);
}
}
/**
* Checks the current character, making sure that it is the expected character.
*
* @param ch the character expected
* @throws JSONParseException if the current character does not match the given character
*/
public boolean check(final char ch) {
return get() == ch;
}
/**
* Advances the position in the string past any whitespace.
*/
public void skipWS() {
while (pos < s.length() && Character.isWhitespace(s.charAt(pos))) {
pos++;
}
}
/**
* Returns the current character. Returns -1 if there are no more characters.
*
* @return the next character
*/
public char get() {
skipWS();
if (pos < s.length()) {
return s.charAt(pos);
}
return (char) -1;
}
/**
* Parses a string.
*
* @return the next string.
* @throws JSONParseException if invalid JSON is found
*/
public String parseString(final boolean needQuote) {
char quot = 0;
if (check('\'')) {
quot = '\'';
} else if (check('\"')) {
quot = '\"';
} else if (needQuote) {
throw new JSONParseException(s, pos);
}
char current;
if (quot > 0) {
read(quot);
}
StringBuilder buf = new StringBuilder();
int start = pos;
while (pos < s.length()) {
current = s.charAt(pos);
if (quot > 0) {
if (current == quot) {
break;
}
} else {
if (current == ':' || current == ' ') {
break;
}
}
if (current == '\\') {
pos++;
char x = get();
char special = 0;
//CHECKSTYLE:OFF
switch (x) {
case 'u': // decode unicode
buf.append(s.substring(start, pos - 1));
pos++;
int tempPos = pos;
readHex();
readHex();
readHex();
readHex();
int codePoint = Integer.parseInt(s.substring(tempPos, tempPos + 4), 16);
buf.append((char) codePoint);
start = pos;
continue;
case 'n':
special = '\n';
break;
case 'r':
special = '\r';
break;
case 't':
special = '\t';
break;
case 'b':
special = '\b';
break;
case '"':
special = '\"';
break;
case '\\':
special = '\\';
break;
default:
break;
}
//CHECKSTYLE:ON
buf.append(s.substring(start, pos - 1));
if (special != 0) {
pos++;
buf.append(special);
}
start = pos;
continue;
}
pos++;
}
buf.append(s.substring(start, pos));
if (quot > 0) {
read(quot);
}
return buf.toString();
}
/**
* Parses a number.
*
* @return the next number (int or double).
* @throws JSONParseException if invalid JSON is found
*/
public Number parseNumber() {
get();
int start = this.pos;
boolean isDouble = false;
if (check('-') || check('+')) {
pos++;
}
outer:
while (pos < s.length()) {
switch (s.charAt(pos)) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
pos++;
break;
case '.':
isDouble = true;
parseFraction();
break;
case 'e':
case 'E':
isDouble = true;
parseExponent();
break;
default:
break outer;
}
}
try {
if (isDouble) {
return Double.valueOf(s.substring(start, pos));
}
Long val = Long.valueOf(s.substring(start, pos));
if (val <= Integer.MAX_VALUE && val >= Integer.MIN_VALUE) {
return val.intValue();
}
return val;
} catch (NumberFormatException e) {
throw new JSONParseException(s, start, e);
}
}
/**
* Advances the pointed through .digits.
*/
public void parseFraction() {
// get past .
pos++;
outer:
while (pos < s.length()) {
switch (s.charAt(pos)) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
pos++;
break;
case 'e':
case 'E':
parseExponent();
break;
default:
break outer;
}
}
}
/**
* Advances the pointer through the exponent.
*/
public void parseExponent() {
// get past E
pos++;
if (check('-') || check('+')) {
pos++;
}
outer:
while (pos < s.length()) {
switch (s.charAt(pos)) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
pos++;
break;
default:
break outer;
}
}
}
/**
* Parses the next array.
*
* @return the array
* @throws JSONParseException if invalid JSON is found
*/
public Object parseArray() {
return parseArray(null);
}
/**
* Parses the next array.
*
* @return the array
* @throws JSONParseException if invalid JSON is found
*/
protected Object parseArray(final String name) {
if (name != null) {
_callback.arrayStart(name);
} else {
_callback.arrayStart();
}
read('[');
int i = 0;
char current = get();
while (current != ']') {
String elemName = String.valueOf(i++);
Object elem = parse(elemName);
doCallback(elemName, elem);
if ((current = get()) == ',') {
read(',');
} else if (current == ']') {
break;
} else {
throw new JSONParseException(s, pos);
}
}
read(']');
return _callback.arrayDone();
}
}