Java Mongo 自定义序列化笔记

从insert方法入手

1. org.springframework.data.mongodb.repository.support.SimpleMongoRepository.java insert

2. org.springframework.data.mongodb.core.MongoTemplate.java toDbObject

3. org.springframework.data.mongodb.core.convert.MappingMongoConverter.java writeInternal

看到关键代码：

        MongoPersistentEntity<?> entity = mappingContext.getPersistentEntity(entityType);
        writeInternal(obj, dbo, entity);
        addCustomTypeKeyIfNecessary(typeHint, obj, dbo);

第2处 writeInternal 出现：

    // Write the properties
        entity.doWithProperties(new PropertyHandler<MongoPersistentProperty>() {
            public void doWithPersistentProperty(MongoPersistentProperty prop) {

                if (prop.equals(idProperty) || !prop.isWritable()) {
                    return;
                }

                Object propertyObj = accessor.getProperty(prop);

                if (null != propertyObj) {

                    if (!conversions.isSimpleType(propertyObj.getClass())) {
                        writePropertyInternal(propertyObj, dbo, prop);
                    } else {
                        writeSimpleInternal(propertyObj, dbo, prop);
                    }
                }
            }
        });

其中:

entity = org.springframework.data.mapping.model.BasicPersistentEntity

writePropertyInternal 进入非简单属性的写入。

再调用 writeInternal 进行属性写入，可以看出是把非简单属性当成对象进行循环写入的。

在写入 id 时，调用：

org.springframework.data.mongodb.core.convert.QueryMapper.convertId 方法

/**
     * Converts the given raw id value into either {@link ObjectId} or {@link String}.
     * 
     * @param id
     * @return
     */
    public Object convertId(Object id) {

        if (id == null) {
            return null;
        }

        if (id instanceof String) {
            return ObjectId.isValid(id.toString()) ? conversionService.convert(id, ObjectId.class) : id;
        }

        try {
            return conversionService.canConvert(id.getClass(), ObjectId.class) ? conversionService.convert(id, ObjectId.class)
                    : delegateConvertToMongoType(id, null);
        } catch (ConversionException o_O) {
            return delegateConvertToMongoType(id, null);
        }
    }