Error handling "null" String when Feature.MINIMIZE_QUOTES is active

[stefanleh]

When serializing a String with content "null" and Feature.MINIMIZE_QUOTES is active the "null" value does not get quoted. Therefore when deserializing the value is not a String but null.

In com.fasterxml.jackson.dataformat.yaml.YAMLGenerator.writeString(String) there is a special handling for boolean content like "true" and "false". Therefore id suggest to add special handling for "null" and "NULL" string values there as well.

What do you think about that?

[stefanleh]

This works for me:

package com.oxaion.open.gen.model.serializer;

import java.io.IOException;
import java.io.Writer;

import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.io.IOContext;
import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
import com.fasterxml.jackson.dataformat.yaml.YAMLGenerator;

@SuppressWarnings("serial")
public class OxaionYamlFactory extends YAMLFactory {

	// Strings quoted for fun
	private final static Character STYLE_QUOTED = Character.valueOf('"');
	// Strings in literal (block) style
	private final static Character STYLE_LITERAL = Character.valueOf('|');
	private final static Character STYLE_PLAIN = null;
	
	@Override
	protected YAMLGenerator _createGenerator(Writer out, IOContext ctxt) throws IOException {

		int feats = _yamlGeneratorFeatures;
		YAMLGenerator gen = new YAMLGenerator(ctxt, _generatorFeatures, feats, _objectCodec, out, _version) {
			
			@Override
			public void writeString(String text) throws IOException, JsonGenerationException {
			
				  if (text == null) {
						writeNull();
						return;
					}
					_verifyValueWrite("write String value");
					Character style = STYLE_QUOTED;
					if (Feature.MINIMIZE_QUOTES.enabledIn(_formatFeatures) && !isBooleanContent(text) && !isStringNullContent(text)) {
					  // If this string could be interpreted as a number, it must be quoted.
						if (Feature.ALWAYS_QUOTE_NUMBERS_AS_STRINGS.enabledIn(_formatFeatures)
								&& PLAIN_NUMBER_P.matcher(text).matches()) {
							style = STYLE_QUOTED;
						} else if (text.indexOf('\n') >= 0) {
							style = STYLE_LITERAL;
						} else {
							style = STYLE_PLAIN;
						}
					} else if (Feature.LITERAL_BLOCK_STYLE.enabledIn(_formatFeatures) && text.indexOf('\n') >= 0) {
						style = STYLE_LITERAL;
					}
					_writeScalar(text, "string", style);
			}
			
			private boolean isBooleanContent(String text) {
				return text.equals("true") || text.equals("false");
			}
			
			private boolean isStringNullContent(String text) {
				return text.equals("null") || text.equals("NULL");
			}


		};
		// any other initializations? No?
		return gen;
	}

}

[cowtowncoder]

Sorry, I had missed this one. Adding on my W-I-P list. Sounds like worthy addition, yes.

[cowtowncoder]

Thank you for reporting this, suggesting the fix. I manually merged fix in 2.10, will be in 2.10.0