private JsonToken nextInObject(boolean firstElement) throws IOException {
/*
* Read delimiters. Either a comma/semicolon separating this and the
* previous name-value pair, or a close brace to denote the end of the
* object.
*/
if (firstElement) {
/* Peek to see if this is the empty object. */
switch (nextNonWhitespace()) {
case '}':
pop();
return token = JsonToken.END_OBJECT;
default:
pos--;
}
} else {
switch (nextNonWhitespace()) {
case '}':
pop();
return token = JsonToken.END_OBJECT;
case ';':
case ',':
break;
default:
throw syntaxError("Unterminated object");
}
}
/* Read the name. */
int quote = nextNonWhitespace();
switch (quote) {
case '\'':
checkLenient(); // fall-through
case '"':
name = nextString((char) quote);
break;
default:
checkLenient();
pos--;
name = nextLiteral(false);
if (name.isEmpty()) {
throw syntaxError("Expected name");
}
}
replaceTop(JsonScope.DANGLING_NAME);
return token = JsonToken.NAME;
}
private JsonToken objectValue() throws IOException {
/*
* Read the name/value separator. Usually a colon ':'. In lenient mode
* we also accept an equals sign '=', or an arrow "=>".
*/
switch (nextNonWhitespace()) {
case ':':
break;
case '=':
checkLenient();
if ((pos < limit || fillBuffer(1)) && buffer[pos] == '>') {
pos++;
}
break;
default:
throw syntaxError("Expected ':'");
}
replaceTop(JsonScope.NONEMPTY_OBJECT);
return nextValue();
}
/** Returns the type of the next token without consuming it. */
public JsonToken peek() throws IOException {
if (token != null) {
return token;
}
switch (peekStack()) {
case EMPTY_DOCUMENT:
replaceTop(JsonScope.NONEMPTY_DOCUMENT);
JsonToken firstToken = nextValue();
if (!lenient && token != JsonToken.BEGIN_ARRAY && token != JsonToken.BEGIN_OBJECT) {
throw new IOException("Expected JSON document to start with '[' or '{' but was " + token);
}
return firstToken;
case EMPTY_ARRAY:
return nextInArray(true);
case NONEMPTY_ARRAY:
return nextInArray(false);
case EMPTY_OBJECT:
return nextInObject(true);
case DANGLING_NAME:
return objectValue();
case NONEMPTY_OBJECT:
return nextInObject(false);
case NONEMPTY_DOCUMENT:
try {
JsonToken token = nextValue();
if (lenient) {
return token;
}
throw syntaxError("Expected EOF");
} catch (EOFException e) {
return token = JsonToken.END_DOCUMENT; // TODO: avoid throwing here?
}
case CLOSED:
throw new IllegalStateException("JsonReader is closed");
default:
throw new AssertionError();
}
}
private JsonToken nextInArray(boolean firstElement) throws IOException {
if (firstElement) {
replaceTop(JsonScope.NONEMPTY_ARRAY);
} else {
/* Look for a comma before each element after the first element. */
switch (nextNonWhitespace()) {
case ']':
pop();
return token = JsonToken.END_ARRAY;
case ';':
checkLenient(); // fall-through
case ',':
break;
default:
throw syntaxError("Unterminated array");
}
}
switch (nextNonWhitespace()) {
case ']':
if (firstElement) {
pop();
return token = JsonToken.END_ARRAY;
}
// fall-through to handle ",]"
case ';':
case ',':
/* In lenient mode, a 0-length literal means 'null' */
checkLenient();
pos--;
value = "null";
return token = JsonToken.NULL;
default:
pos--;
return nextValue();
}
}