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feilong is a suite of core and expanded libraries that include utility classes, http, excel,cvs, io classes, and much much more.
/*
* Copyright 2002-2009 the original author or authors.
*
* 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.feilong.lib.json;
import static com.feilong.core.lang.StringUtil.EMPTY;
import com.feilong.lib.lang3.math.NumberUtils;
/**
* A JSONTokener takes a source string and extracts characters and tokens from it.
*
*
* It is used by the JSONObject and JSONArray constructors to parse JSON source strings.
*
*
* @author JSON.org
* @version 4
*/
public class JSONTokener{
/**
* The index of the next character.
*/
private int myIndex;
/**
* The source string being tokenized.
*/
private final String sourceJson;
//---------------------------------------------------------------
/**
* Construct a JSONTokener from a string.
*
* @param json
* A source string.
*/
public JSONTokener(String json){
this.myIndex = 0;
this.sourceJson = json != null ? json.trim() : EMPTY;
if (sourceJson.length() > 0){
char first = sourceJson.charAt(0);
char last = sourceJson.charAt(sourceJson.length() - 1);
if (first == '[' && last != ']'){
throw syntaxError("Found start '[' ,but miss ']' at the end.");
}
if (first == '{' && last != '}'){
throw syntaxError("Found start '{' ,but miss '}' at the end.");
}
}
}
//---------------------------------------------------------------
/**
* Back up one character. This provides a sort of lookahead capability, so
* that you can test for a digit or letter before attempting to parse the
* next number or identifier.
*/
public void back(){
if (this.myIndex > 0){
this.myIndex -= 1;
}
}
/**
* Get the next character in the source string.
*
* @return The next character, or 0 if past the end of the source string.
*/
public char next(){
if (more()){
char c = this.sourceJson.charAt(this.myIndex);
this.myIndex += 1;
return c;
}
return 0;
}
/**
* Get the next n characters.
*
* @param n
* The number of characters to take.
* @return A string of n characters.
* @throws JSONException
* Substring bounds error if there are not n characters remaining in the source string.
*/
public String next(int n){
int i = this.myIndex;
int j = i + n;
if (j >= this.sourceJson.length()){
throw syntaxError("Substring bounds error");
}
this.myIndex += n;
return this.sourceJson.substring(i, j);
}
/**
* Get the next char in the string, skipping whitespace and comments (slashslash, slashstar, and hash).
*
* @return A character, or 0 if there are no more characters.
*/
public char nextClean(){
for (;;){
char c = next();
if (c == '/'){
switch (next()) {
case '/':
do{
c = next();
}while (c != '\n' && c != '\r' && c != 0);
break;
case '*':
for (;;){
c = next();
if (c == 0){
throw syntaxError("Unclosed comment.");
}
if (c == '*'){
if (next() == '/'){
break;
}
back();
}
}
break;
default:
back();
return '/';
}
}else if (c == '#'){
do{
c = next();
}while (c != '\n' && c != '\r' && c != 0);
}else if (c == 0 || c > ' '){
return c;
}
}
}
/**
* Return the characters up to the next close quote character.
*
* Backslash processing is done.
*
* The formal JSON format does not allow strings in single quotes, but an implementation is allowed to accept them.
*
* @param quote
* The quoting character, either " (double quote) or ' (single
* quote).
* @return A String.
*/
private String nextString(char quote){
char c;
StringBuffer sb = new StringBuffer();
for (;;){
c = next();
switch (c) {
case 0:
case '\n':
case '\r':
throw syntaxError("Unterminated string");
case '\\':
c = next();
switch (c) {
case 'b':
sb.append('\b');
break;
case 't':
sb.append('\t');
break;
case 'n':
sb.append('\n');
break;
case 'f':
sb.append('\f');
break;
case 'r':
sb.append('\r');
break;
case 'u':
sb.append((char) Integer.parseInt(next(4), 16));
break;
case 'x':
sb.append((char) Integer.parseInt(next(2), 16));
break;
default:
sb.append(c);
}
break;
default:
if (c == quote){
return sb.toString();
}
sb.append(c);
}
}
}
/**
* Get the next value.
*
*
* The value can be a Boolean, Double, Integer, JSONArray, JSONObject, Long, or String, or the JSONObject.NULL
* object.
*
*
* @param jsonConfig
*
* @return An object.
*/
public Object nextValue(JsonConfig jsonConfig){
char c = nextClean();
String s;
switch (c) {
case '"':
case '\'':
return nextString(c);
case '{':
back();
return JSONTokenerParser.toJSONObject(this, jsonConfig);
case '[':
back();
return JSONTokenerParser.toJSONArray(this, jsonConfig);
default:
// empty
}
//---------------------------------------------------------------
//Handle unquoted text. This could be the values true, false, or null, or it can be a number. An implementation (such as this one) is allowed to also accept non-standard forms. Accumulate characters until we reach the end of the text or a formatting character.
StringBuffer sb = new StringBuffer();
char b = c;
while (c >= ' ' && ",:]}/\\\"[{;=#".indexOf(c) < 0){
sb.append(c);
c = next();
}
back();
//---------------------------------------------------------------
//If it is true, false, or null, return the proper value.
s = sb.toString().trim();
if (s.equals("")){
throw syntaxError("Missing value.");
}
if (s.equalsIgnoreCase("true")){
return Boolean.TRUE;
}
if (s.equalsIgnoreCase("false")){
return Boolean.FALSE;
}
if (s.equals("null")){
return JSONNull.getInstance();
}
//---------------------------------------------------------------
//If it might be a number, try converting it. We support the 0- and 0x-conventions. If a number cannot be produced, then the value will just be a string. Note that the 0-, 0x-, plus, and implied string conventions are non-standard. A JSON parser is free to accept non-JSON forms as long as it accepts all correct JSON forms.
if ((b >= '0' && b <= '9') || b == '.' || b == '-' || b == '+'){
if (b == '0'){
if (s.length() > 2 && (s.charAt(1) == 'x' || s.charAt(1) == 'X')){
try{
return Integer.parseInt(s.substring(2), 16);
}catch (Exception e){
/* Ignore the error */
}
}else{
try{
return Integer.parseInt(s, 8);
}catch (Exception e){
/* Ignore the error */
}
}
}
try{
return NumberUtils.createNumber(s);
}catch (Exception e){
return s;
}
}
//---------------------------------------------------------------
switch (peek()) {
case ',':
case '}':
case '{':
case '[':
case ']':
throw new JSONException("Unquotted string '" + s + "'");
default:
break;
}
//---------------------------------------------------------------
return s;
}
/**
* Look at the next character in the source string.
*
* @return The next character, or 0 if past the end of the source string.
*/
public char peek(){
if (more()){
char c = this.sourceJson.charAt(this.myIndex);
return c;
}
return 0;
}
public void reset(){
this.myIndex = 0;
}
/**
* Determine if the source string still contains characters that next() can
* consume.
*
* @return true if not yet at the end of the source.
*/
private boolean more(){
return this.myIndex < this.sourceJson.length();
}
//---------------------------------------------------------------
/**
* Make a JSONException to signal a syntax error.
*
* @param message
* The error message.
* @return A JSONException object, suitable for throwing
*/
public JSONException syntaxError(String message){
return new JSONException(message + toString());
}
/**
* Make a printable string of this JSONTokener.
*
* @return " at character [this.myIndex] of [this.mySource]"
*/
@Override
public String toString(){
return " at character " + this.myIndex + " of " + this.sourceJson;
}
}