public void parse(ParseContext context) throws IOException {
        final List<Field> fields = new ArrayList<>(2);
        try {
            parseCreateField(context, fields);//實際Filed解析方法
            for (Field field : fields) {
                if (!customBoost()) {//設(shè)置boost
                    field.setBoost(boost);
                }
                if (context.listener().beforeFieldAdded(this, field, context)) {
                    context.doc().add(field);//將解析完成的Field加入到context中
                }
            }
        } catch (Exception e) {
            throw new MapperParsingException("failed to parse [" + names.fullName() + "]", e);
        }
        multiFields.parse(this, context);//進行mutiFields解析，MultiFields作用是對同一個field做不同的定義，如可以進行不同分詞方式的索引這樣便于通過各種方式查詢
        if (copyTo != null) {
            copyTo.parse(context);
        }
    }

protected void parseCreateField(ParseContext context, List<Field> fields) throws IOException {
        ValueAndBoost valueAndBoost = parseCreateFieldForString(context, nullValue, boost);//解析成值和boost
        if (valueAndBoost.value() == null) {
            return;
        }
        if (ignoreAbove > 0 && valueAndBoost.value().length() > ignoreAbove) {
            return;
        }
        if (context.includeInAll(includeInAll, this)) {
            context.allEntries().addText(names.fullName(), valueAndBoost.value(), valueAndBoost.boost());
        }
        if (fieldType.indexed() || fieldType.stored()) {//構(gòu)建LuceneField
            Field field = new Field(names.indexName(), valueAndBoost.value(), fieldType);
            field.setBoost(valueAndBoost.boost());
            fields.add(field);
        }
        if (hasDocValues()) {
            fields.add(new SortedSetDocValuesField(names.indexName(), new BytesRef(valueAndBoost.value())));
        }
        if (fields.isEmpty()) {
            context.ignoredValue(names.indexName(), valueAndBoost.value());
        }
    }
//解析出字段的值和boost
    public static ValueAndBoost parseCreateFieldForString(ParseContext context, String nullValue, float defaultBoost) throws IOException {
        if (context.externalValueSet()) {
            return new ValueAndBoost((String) context.externalValue(), defaultBoost);
        }
        XContentParser parser = context.parser();
        if (parser.currentToken() == XContentParser.Token.VALUE_NULL) {
            return new ValueAndBoost(nullValue, defaultBoost);
        }
        if (parser.currentToken() == XContentParser.Token.START_OBJECT) {
            XContentParser.Token token;
            String currentFieldName = null;
            String value = nullValue;
            float boost = defaultBoost;
            while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                if (token == XContentParser.Token.FIELD_NAME) {
                    currentFieldName = parser.currentName();
                } else {
                    if ("value".equals(currentFieldName) || "_value".equals(currentFieldName)) {
                        value = parser.textOrNull();
                    } else if ("boost".equals(currentFieldName) || "_boost".equals(currentFieldName)) {
                        boost = parser.floatValue();
                    } else {
                        throw new ElasticsearchIllegalArgumentException("unknown property [" + currentFieldName + "]");
                    }
                }
            }
            return new ValueAndBoost(value, boost);
        }
        return new ValueAndBoost(parser.textOrNull(), defaultBoost);
    }

private final DocumentMapperParser docMapperParser;
    private volatile ImmutableMap<String, Object> meta;
    private volatile CompressedString mappingSource;
    private final RootObjectMapper rootObjectMapper;
    private final ImmutableMap<Class<? extends RootMapper>, RootMapper> rootMappers;
    private final RootMapper[] rootMappersOrdered;
    private final RootMapper[] rootMappersNotIncludedInObject;
    private final NamedAnalyzer indexAnalyzer;
    private final NamedAnalyzer searchAnalyzer;
    private final NamedAnalyzer searchQuoteAnalyzer;

public ParsedDocument parse(SourceToParse source, @Nullable ParseListener listener) throws MapperParsingException {
        ParseContext.InternalParseContext context = cache.get();
        if (source.type() != null && !source.type().equals(this.type)) {
            throw new MapperParsingException("Type mismatch, provide type [" + source.type() + "] but mapper is of type [" + this.type + "]");
        }
        source.type(this.type);
        XContentParser parser = source.parser();
        try {
            if (parser == null) {
                parser = XContentHelper.createParser(source.source());
            }
            if (sourceTransforms != null) {
                parser = transform(parser);
            }
            context.reset(parser, new ParseContext.Document(), source, listener);
            // will result in START_OBJECT
            int countDownTokens = 0;
            XContentParser.Token token = parser.nextToken();
            if (token != XContentParser.Token.START_OBJECT) {
                throw new MapperParsingException("Malformed content, must start with an object");
            }
            boolean emptyDoc = false;
            token = parser.nextToken();
            if (token == XContentParser.Token.END_OBJECT) {
                // empty doc, we can handle it...
                emptyDoc = true;
            } else if (token != XContentParser.Token.FIELD_NAME) {
                throw new MapperParsingException("Malformed content, after first object, either the type field or the actual properties should exist");
            }
            // first field is the same as the type, this might be because the
            // type is provided, and the object exists within it or because
            // there is a valid field that by chance is named as the type.
            // Because of this, by default wrapping a document in a type is
            // disabled, but can be enabled by setting
            // index.mapping.allow_type_wrapper to true
            if (type.equals(parser.currentName()) && indexSettings.getAsBoolean(ALLOW_TYPE_WRAPPER, false)) {
                parser.nextToken();
                countDownTokens++;
            }
            for (RootMapper rootMapper : rootMappersOrdered) {
                rootMapper.preParse(context);
            }
            if (!emptyDoc) {
                rootObjectMapper.parse(context);
            }
            for (int i = 0; i < countDownTokens; i++) {
                parser.nextToken();
            }
            for (RootMapper rootMapper : rootMappersOrdered) {
                rootMapper.postParse(context);
            }
        } catch (Throwable e) {
            // if its already a mapper parsing exception, no need to wrap it...
            if (e instanceof MapperParsingException) {
                throw (MapperParsingException) e;
            }
            // Throw a more meaningful message if the document is empty.
            if (source.source() != null && source.source().length() == 0) {
                throw new MapperParsingException("failed to parse, document is empty");
            }
            throw new MapperParsingException("failed to parse", e);
        } finally {
            // only close the parser when its not provided externally
            if (source.parser() == null && parser != null) {
                parser.close();
            }
        }
        // reverse the order of docs for nested docs support, parent should be last
        if (context.docs().size() > 1) {
            Collections.reverse(context.docs());
        }
        // apply doc boost
        if (context.docBoost() != 1.0f) {
            Set<String> encounteredFields = Sets.newHashSet();
            for (ParseContext.Document doc : context.docs()) {
                encounteredFields.clear();
                for (IndexableField field : doc) {
                    if (field.fieldType().indexed() && !field.fieldType().omitNorms()) {
                        if (!encounteredFields.contains(field.name())) {
                            ((Field) field).setBoost(context.docBoost() * field.boost());
                            encounteredFields.add(field.name());
                        }
                    }
                }
            }
        }
        ParsedDocument doc = new ParsedDocument(context.uid(), context.version(), context.id(), context.type(), source.routing(), source.timestamp(), source.ttl(), context.docs(), context.analyzer(),
                context.source(), context.mappingsModified()).parent(source.parent());
        // reset the context to free up memory
        context.reset(null, null, null, null);
        return doc;
    }