package com.lupcode.JSON;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import com.lupcode.JSON.exceptions.JsonParseException;
import com.lupcode.JSON.exceptions.JsonParseUnfinishedException;
import com.lupcode.JSON.utils.LineColumnTracker;
import com.lupcode.Utilities.streams.UTF8CharInputStream;
/** Represents the null values in JSON
* @author LupCode.com (Luca Vogels)
* @since 2020-12-23
*/
public class JsonNull extends JSON {
@Override
protected void toJSON(OutputStream output, boolean prettyPrint, String whitespace) throws IOException {
output.write("null".getBytes(StandardCharsets.UTF_8));
}
@Override
protected JsonNull parseJSON(UTF8CharInputStream input, LineColumnTracker lct) throws JsonParseException, IOException {
// TODO Auto-generated method stub
String c = skipIgnorers(input, lct);
if(c==null){ throw new JsonParseUnfinishedException('n', lct); }
if(!c.equalsIgnoreCase("n")){ throw new JsonParseException('n', c, lct); }
lct.increaseColumn();
c = skipIgnorers(input, lct);
if(c==null){ throw new JsonParseUnfinishedException(new char[]{'u','i'}, lct); }
lct.increaseColumn();
if(c.equalsIgnoreCase("u")){
// parse null
for(int i=0; i<2; i++){
c = skipIgnorers(input, lct);
if(c==null){ throw new JsonParseUnfinishedException(new char[]{'l'}, lct); }
if(!c.equalsIgnoreCase("l")){ throw new JsonParseException('l', c, lct); }
lct.increaseColumn();
}
} else if(c.equalsIgnoreCase("i")){
// parse nil
c = skipIgnorers(input, lct);
if(c==null){ throw new JsonParseUnfinishedException(new char[]{'l'}, lct); }
if(!c.equalsIgnoreCase("l")){ throw new JsonParseException('l', c, lct); }
lct.increaseColumn();
} else {
throw new JsonParseException(new char[]{'u','i'}, c, lct);
}
return this;
}
/** Tries to parse a given JSON string as an {@link JsonNull}
* @param json String that should be parsed
* @return Parsed JSON null
* @throws JsonParseException if JSON string could not be parsed correctly
* @throws NullPointerException if JSON string is null
*/
public static JsonNull parse(String json) throws JsonParseException, NullPointerException {
return new JsonNull().parseJSON(json);
}
/** Tries to parse a given JSON string as an {@link JsonNull}
* @param json String that should be parsed
* @param offset Offset where to start reading the JSON string
* @return Parse JSON null
* @throws JsonParseException if JSON string could not be parsed correctly
* @throws NullPointerException if JSON string is null
*/
public static JsonNull parse(String json, int offset) throws JsonParseException, NullPointerException {
return new JsonNull().parseJSON(json, offset);
}
/** Tries to parse a {@link JsonNull} from a given {@link InputStream} in UTF-8
* @param json Stream in UTF-8 that should be parsed
* @return Parse JSON null
* @throws JsonParseException if input could not be parsed correctly
* @throws IOException if an error while reading {@link InputStream} occurred
* @throws NullPointerException if input is null
*/
public static JsonNull parse(UTF8CharInputStream input) throws JsonParseException, IOException, NullPointerException {
return new JsonNull().parseJSON(input);
}
/**
* Tries to parse a {@link JsonNull} from a given {@link File}
* @param file File the JSON data should be read from
* @return Parsed JSON null
* @throws JsonParseException if file could not be parsed correctly
* @throws NullPointerException if file is null
* @throws IOException if an error occurs while reading the {@link File}
*/
public static JsonNull parse(File file) throws JsonParseException, NullPointerException, IOException{
return new JsonNull().parseJSON(file);
}
/**
* Tries to parse a {@link JsonNull} from a given {@link URL}
* @param url URL the JSON data should be read from
* @return Parsed JSON null
* @throws JsonParseException if {@link URL} could not be parsed correctly
* @throws NullPointerException if {@link URL} is null
* @throws IOException if an error occurs while reading the from the {@link URL}
*/
public static JsonNull parse(URL url) throws JsonParseException, NullPointerException, IOException{
return new JsonNull().parseJSON(url);
}
}