com.reandroid.json.JSONTokener Maven / Gradle / Ivy
/*
* Copyright (c) 2002 JSON.org (now "Public Domain")
* This is NOT property of REAndroid
* This package is renamed from org.json.* to avoid class conflict when used on anroid platforms
*/
package com.reandroid.json;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
public class JSONTokener {
/** current read character position on the current line. */
private long character;
/** flag to indicate if the end of the input has been found. */
private boolean eof;
/** current read index of the input. */
private long index;
/** current line of the input. */
private long line;
/** previous character read from the input. */
private char previous;
/** Reader for the input. */
private final Reader reader;
/** flag to indicate that a previous character was requested. */
private boolean usePrevious;
/** the number of characters read in the previous line. */
private long characterPreviousLine;
public JSONTokener(Reader reader) {
this.reader = reader.markSupported()
? reader
: new BufferedReader(reader);
this.eof = false;
this.usePrevious = false;
this.previous = 0;
this.index = 0;
this.character = 1;
this.characterPreviousLine = 0;
this.line = 1;
}
public JSONTokener(InputStream inputStream) {
this(new InputStreamReader(inputStream));
}
public JSONTokener(String s) {
this(new StringReader(s));
}
public void back() throws JSONException {
if (this.usePrevious || this.index <= 0) {
throw new JSONException("Stepping back two steps is not supported");
}
this.decrementIndexes();
this.usePrevious = true;
this.eof = false;
}
private void decrementIndexes() {
this.index--;
if(this.previous=='\r' || this.previous == '\n') {
this.line--;
this.character=this.characterPreviousLine ;
} else if(this.character > 0){
this.character--;
}
}
public static int dehexchar(char c) {
if (c >= '0' && c <= '9') {
return c - '0';
}
if (c >= 'A' && c <= 'F') {
return c - ('A' - 10);
}
if (c >= 'a' && c <= 'f') {
return c - ('a' - 10);
}
return -1;
}
public boolean end() {
return this.eof && !this.usePrevious;
}
public boolean more() throws JSONException {
if(this.usePrevious) {
return true;
}
try {
this.reader.mark(1);
} catch (IOException e) {
throw new JSONException("Unable to preserve stream position", e);
}
try {
// -1 is EOF, but next() can not consume the null character '\0'
if(this.reader.read() <= 0) {
this.eof = true;
return false;
}
this.reader.reset();
} catch (IOException e) {
throw new JSONException("Unable to read the next character from the stream", e);
}
return true;
}
public char next() throws JSONException {
int c;
if (this.usePrevious) {
this.usePrevious = false;
c = this.previous;
} else {
try {
c = this.reader.read();
} catch (IOException exception) {
throw new JSONException(exception);
}
}
if (c <= 0) { // End of stream
this.eof = true;
return 0;
}
this.incrementIndexes(c);
this.previous = (char) c;
return this.previous;
}
private void incrementIndexes(int c) {
if(c > 0) {
this.index++;
if(c=='\r') {
this.line++;
this.characterPreviousLine = this.character;
this.character=0;
}else if (c=='\n') {
if(this.previous != '\r') {
this.line++;
this.characterPreviousLine = this.character;
}
this.character=0;
} else {
this.character++;
}
}
}
public char next(char c) throws JSONException {
char n = this.next();
if (n != c) {
if(n > 0) {
throw this.syntaxError("Expected '" + c + "' and instead saw '" +
n + "'");
}
throw this.syntaxError("Expected '" + c + "' and instead saw ''");
}
return n;
}
public String next(int n) throws JSONException {
if (n == 0) {
return "";
}
char[] chars = new char[n];
int pos = 0;
while (pos < n) {
chars[pos] = this.next();
if (this.end()) {
throw this.syntaxError("Substring bounds error");
}
pos += 1;
}
return new String(chars);
}
public char nextClean() throws JSONException {
for (;;) {
char c = this.next();
if (c == 0 || c > ' ') {
return c;
}
}
}
public String nextString(char quote) throws JSONException {
char c;
StringBuilder sb = new StringBuilder();
for (;;) {
c = this.next();
switch (c) {
case 0:
case '\n':
case '\r':
throw this.syntaxError("Unterminated string");
case '\\':
c = this.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':
try {
sb.append((char)Integer.parseInt(this.next(4), 16));
} catch (NumberFormatException e) {
throw this.syntaxError("Illegal escape.", e);
}
break;
case '"':
case '\'':
case '\\':
case '/':
sb.append(c);
break;
default:
throw this.syntaxError("Illegal escape.");
}
break;
default:
if (c == quote) {
return sb.toString();
}
sb.append(c);
}
}
}
public String nextTo(char delimiter) throws JSONException {
StringBuilder sb = new StringBuilder();
for (;;) {
char c = this.next();
if (c == delimiter || c == 0 || c == '\n' || c == '\r') {
if (c != 0) {
this.back();
}
return sb.toString().trim();
}
sb.append(c);
}
}
public String nextTo(String delimiters) throws JSONException {
char c;
StringBuilder sb = new StringBuilder();
for (;;) {
c = this.next();
if (delimiters.indexOf(c) >= 0 || c == 0 ||
c == '\n' || c == '\r') {
if (c != 0) {
this.back();
}
return sb.toString().trim();
}
sb.append(c);
}
}
public Object nextValue() throws JSONException {
char c = this.nextClean();
String string;
switch (c) {
case '"':
case '\'':
return this.nextString(c);
case '{':
this.back();
return new JSONObject(this);
case '[':
this.back();
return new JSONArray(this);
}
/*
* 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.
*/
StringBuilder sb = new StringBuilder();
while (c >= ' ' && ",:]}/\\\"[{;=#".indexOf(c) < 0) {
sb.append(c);
c = this.next();
}
if (!this.eof) {
this.back();
}
string = sb.toString().trim();
if ("".equals(string)) {
throw this.syntaxError("Missing value");
}
return JSONObject.stringToValue(string);
}
public char skipTo(char to) throws JSONException {
char c;
try {
long startIndex = this.index;
long startCharacter = this.character;
long startLine = this.line;
this.reader.mark(1000000);
do {
c = this.next();
if (c == 0) {
// in some readers, reset() may throw an exception if
// the remaining portion of the input is greater than
// the mark size (1,000,000 above).
this.reader.reset();
this.index = startIndex;
this.character = startCharacter;
this.line = startLine;
return 0;
}
} while (c != to);
this.reader.mark(1);
} catch (IOException exception) {
throw new JSONException(exception);
}
this.back();
return c;
}
public JSONException syntaxError(String message) {
return new JSONException(message + this.toString());
}
public JSONException syntaxError(String message, Throwable causedBy) {
return new JSONException(message + this.toString(), causedBy);
}
@Override
public String toString() {
return " at " + this.index + " [character " + this.character + " line " +
this.line + "]";
}
}
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