com.google.api.client.json.gson.GsonParser Maven / Gradle / Ivy
/*
* Copyright (c) 2011 Google 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.google.api.client.json.gson;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.JsonParser;
import com.google.api.client.json.JsonToken;
import com.google.gson.stream.JsonReader;
import java.io.EOFException;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.List;
/**
* Low-level JSON serializer implementation based on GSON.
*
* Implementation is not thread-safe.
*
* @author Yaniv Inbar
*/
class GsonParser extends JsonParser {
private final JsonReader reader;
private final GsonFactory factory;
private List currentNameStack = new ArrayList();
private JsonToken currentToken;
private String currentText;
GsonParser(GsonFactory factory, JsonReader reader) {
this.factory = factory;
this.reader = reader;
reader.setLenient(false);
}
@Override
public void close() throws IOException {
reader.close();
}
@Override
public String getCurrentName() {
return currentNameStack.isEmpty() ? null : currentNameStack.get(currentNameStack.size() - 1);
}
@Override
public JsonToken getCurrentToken() {
return currentToken;
}
@Override
public JsonFactory getFactory() {
return factory;
}
@Override
public byte getByteValue() throws IOException {
checkNumber();
return Byte.parseByte(currentText);
}
@Override
public short getShortValue() throws IOException {
checkNumber();
return Short.parseShort(currentText);
}
@Override
public int getIntValue() throws IOException {
checkNumber();
return Integer.parseInt(currentText);
}
@Override
public float getFloatValue() throws IOException {
checkNumber();
return Float.parseFloat(currentText);
}
@Override
public BigInteger getBigIntegerValue() throws IOException {
checkNumber();
return new BigInteger(currentText);
}
@Override
public BigDecimal getDecimalValue() throws IOException {
checkNumber();
return new BigDecimal(currentText);
}
@Override
public double getDoubleValue() throws IOException {
checkNumber();
return Double.parseDouble(currentText);
}
@Override
public long getLongValue() throws IOException {
checkNumber();
return Long.parseLong(currentText);
}
private void checkNumber() throws IOException {
if (currentToken != JsonToken.VALUE_NUMBER_INT
&& currentToken != JsonToken.VALUE_NUMBER_FLOAT) {
throw new IOException("Token is not a number");
}
}
@Override
public String getText() {
return currentText;
}
@Override
public JsonToken nextToken() throws IOException {
if (currentToken != null) {
switch (currentToken) {
case START_ARRAY:
reader.beginArray();
currentNameStack.add(null);
break;
case START_OBJECT:
reader.beginObject();
currentNameStack.add(null);
break;
default:
break;
}
}
// work around bug in GSON parser that it throws an EOFException for an empty document
// see https://github.com/google/gson/issues/330
com.google.gson.stream.JsonToken peek;
try {
peek = reader.peek();
} catch (EOFException e) {
peek = com.google.gson.stream.JsonToken.END_DOCUMENT;
}
switch (peek) {
case BEGIN_ARRAY:
currentText = "[";
currentToken = JsonToken.START_ARRAY;
break;
case END_ARRAY:
currentText = "]";
currentToken = JsonToken.END_ARRAY;
currentNameStack.remove(currentNameStack.size() - 1);
reader.endArray();
break;
case BEGIN_OBJECT:
currentText = "{";
currentToken = JsonToken.START_OBJECT;
break;
case END_OBJECT:
currentText = "}";
currentToken = JsonToken.END_OBJECT;
currentNameStack.remove(currentNameStack.size() - 1);
reader.endObject();
break;
case BOOLEAN:
if (reader.nextBoolean()) {
currentText = "true";
currentToken = JsonToken.VALUE_TRUE;
} else {
currentText = "false";
currentToken = JsonToken.VALUE_FALSE;
}
break;
case NULL:
currentText = "null";
currentToken = JsonToken.VALUE_NULL;
reader.nextNull();
break;
case STRING:
currentText = reader.nextString();
currentToken = JsonToken.VALUE_STRING;
break;
case NUMBER:
currentText = reader.nextString();
currentToken =
currentText.indexOf('.') == -1
? JsonToken.VALUE_NUMBER_INT
: JsonToken.VALUE_NUMBER_FLOAT;
break;
case NAME:
currentText = reader.nextName();
currentToken = JsonToken.FIELD_NAME;
currentNameStack.set(currentNameStack.size() - 1, currentText);
break;
default:
currentText = null;
currentToken = null;
}
return currentToken;
}
@Override
public JsonParser skipChildren() throws IOException {
if (currentToken != null) {
switch (currentToken) {
case START_ARRAY:
reader.skipValue();
currentText = "]";
currentToken = JsonToken.END_ARRAY;
break;
case START_OBJECT:
reader.skipValue();
currentText = "}";
currentToken = JsonToken.END_OBJECT;
break;
default:
break;
}
}
return this;
}
}