org.cuberact.json.parser.JsonParser Maven / Gradle / Ivy
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/*
* Copyright 2017 Michal Nikodim
*
* 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 org.cuberact.json.parser;
import org.cuberact.json.JsonException;
import org.cuberact.json.builder.JsonBuilder;
import org.cuberact.json.builder.JsonBuilderTree;
import org.cuberact.json.input.JsonInput;
import org.cuberact.json.input.JsonInputCharSequence;
import org.cuberact.json.input.JsonInputReader;
import java.io.Reader;
import java.util.Objects;
/**
* Parse {@link JsonInput} and build result with {@link JsonBuilder}
*
* JsonParser is thread-safe with {@link JsonBuilderTree}
*
* @author Michal Nikodim ([email protected])
*/
public class JsonParser {
private final JsonBuilder builder;
public JsonParser() {
this(JsonBuilder.DEFAULT);
}
public JsonParser(JsonBuilder builder) {
this.builder = Objects.requireNonNull(builder, "builder");
Objects.requireNonNull(builder.getNumberConverter(), "numberConverter");
}
/**
* @param input - {@link CharSequence}
* @param - {@link JsonBuilder#createJsonObject()} or {@link JsonBuilder#createJsonArray()}
* @return JsonBuilder result - {@link JsonBuilder#createJsonObject()} or {@link JsonBuilder#createJsonArray()}
*/
public E parse(CharSequence input) {
return parse(new JsonInputCharSequence(input));
}
/**
* @param input - {@link Reader} - JsonParser doesn't close input reader
* @param - {@link JsonBuilder#createJsonObject()} or {@link JsonBuilder#createJsonArray()}
* @return JsonBuilder result - {@link JsonBuilder#createJsonObject()} or {@link JsonBuilder#createJsonArray()}
*/
public E parse(Reader input) {
return parse(new JsonInputReader(input));
}
/**
* @param input - {@link JsonInput}
* @param - {@link JsonBuilder#createJsonObject()} or {@link JsonBuilder#createJsonArray()}
* @return JsonBuilder result - {@link JsonBuilder#createJsonObject()} or {@link JsonBuilder#createJsonArray()}
*/
@SuppressWarnings("unchecked")
public E parse(JsonInput input) {
Object root;
switch (input.nextImportantChar()) {
case '{':
root = builder.createJsonObject();
parseObject(input, root);
break;
case '[':
root = builder.createJsonArray();
parseArray(input, root);
break;
default:
throw new JsonException(input.buildExceptionMessage("Expected { or ["));
}
return (E) root;
}
private void parseObject(JsonInput input, Object jsonObject) {
for (; ; ) {
switch (input.nextImportantChar()) {
case '"':
final String attr = Token.consumeString(input);
if (input.nextImportantChar() != ':') {
throw new JsonException(input.buildExceptionMessage("Expected :"));
}
switch (input.nextImportantChar()) {
case '"':
builder.addToJsonObject(jsonObject, attr, Token.consumeString(input));
break;
case '{':
final Object jsonSubObject = builder.createJsonObject();
builder.addToJsonObject(jsonObject, attr, jsonSubObject);
parseObject(input, jsonSubObject);
break;
case '[':
final Object jsonSubArray = builder.createJsonArray();
builder.addToJsonObject(jsonObject, attr, jsonSubArray);
parseArray(input, jsonSubArray);
break;
case 't':
Token.consumeTrue(input);
builder.addToJsonObject(jsonObject, attr, Boolean.TRUE);
break;
case 'f':
Token.consumeFalse(input);
builder.addToJsonObject(jsonObject, attr, Boolean.FALSE);
break;
case 'n':
Token.consumeNull(input);
builder.addToJsonObject(jsonObject, attr, null);
break;
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
builder.addToJsonObject(jsonObject, attr, Token.consumeNumber(input, builder.getNumberConverter()));
break;
default:
throw new JsonException(input.buildExceptionMessage("Expected \" or ] or number or boolean or null"));
}
break;
case '}':
return;
default:
throw new JsonException(input.buildExceptionMessage("Expected \""));
}
switch (input.nextImportantChar()) {
case ',':
continue;
case '}':
return;
default:
throw new JsonException(input.buildExceptionMessage("Expected } or ,"));
}
}
}
private void parseArray(JsonInput input, Object jsonArray) {
for (; ; ) {
switch (input.nextImportantChar()) {
case '"':
builder.addToJsonArray(jsonArray, Token.consumeString(input));
break;
case '{':
final Object jsonSubObject = builder.createJsonObject();
builder.addToJsonArray(jsonArray, jsonSubObject);
parseObject(input, jsonSubObject);
break;
case '[':
final Object jsonSubArray = builder.createJsonArray();
builder.addToJsonArray(jsonArray, jsonSubArray);
parseArray(input, jsonSubArray);
break;
case 't':
Token.consumeTrue(input);
builder.addToJsonArray(jsonArray, Boolean.TRUE);
break;
case 'f':
Token.consumeFalse(input);
builder.addToJsonArray(jsonArray, Boolean.FALSE);
break;
case 'n':
Token.consumeNull(input);
builder.addToJsonArray(jsonArray, null);
break;
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
builder.addToJsonArray(jsonArray, Token.consumeNumber(input, builder.getNumberConverter()));
break;
case ']':
return;
default:
throw new JsonException(input.buildExceptionMessage("Expected \" or ] or number or boolean or null"));
}
switch (input.nextImportantChar()) {
case ',':
continue;
case ']':
return;
default:
throw new JsonException(input.buildExceptionMessage("Expected ] or ,"));
}
}
}
}