附件类型
The attachment type allows to index different “attachment” type field (encoded as base64), for example, microsoft office formats, ODF, ePub, HTML, and so on (full list can be found here).
note："attachment" 编码为 base64 ,
The attachment type is provided as a plugin extension. The plugin is a simple zip file that can be downloaded and placed under $ES_HOME/plugins location. It will be automatically detected and the attachment type will be added.
click： https://github.com/goog/doc.elasticsearch.cn/blob/master/tutorials/_posts/2011-07-18-attachment-type-in-action.textile
Note, the attachment type is experimental(试验性的).
Using the attachment type is simple, in your mapping JSON, simply set a certain JSON element as attachment, for example:
使用attachment type 很简单, 在mapping JSON里面简单的设置一个JSON元素为attachment类型, 例如:
{
"person" : {
"properties" : {
"my_attachment" : { "type" : "attachment" }
}
}
}
In this case, the JSON to index can be:
{
"my_attachment" : "... base64 encoded attachment ..."
}
Or it is possible to use more elaborated JSON if content type or resource name need to be set explicitly:
如果内容类型或资源名称需要设置清楚，可能需要稍微一点复杂的JSON
{
“my_attachment” : {
“_content_type” : “application/pdf”,
“_name” : “resource/name/of/my.pdf”,
“content” : “… base64 encoded attachment …”
}
}
The attachment type not only indexes the content of the doc, but also automatically adds meta data on the attachment as well (when available). The metadata supported are: date, title, author, and keywords. They can be queried using the “dot notation”, for example: my_attachment.author.
The attachment type 会自动添加元数据，支持的元数据有: date, title, author, and keywords. 可能还不够用…
Both the meta data and the actual content are simple core type mappers (string, date, …), thus, they can be controlled in the mappings. For example:
meta data 和 实际的内容基本都是type mappers (string, date, …), 因此可以在 mappings里面设置. 例如:
{
"person" : {
"properties" : {
"file" : {
"type" : "attachment",
"fields" : {
"file" : {"index" : "no"},
"date" : {"store" : "yes"},
"author" : {"analyzer" : "myAnalyzer"}
}
}
}
}
}
“person” 为mapping type , “file” 为document的Key, 所以文件被 attachment type 解析
p. In the above example, the actual content indexed is mapped under fields name file, and we decide not to index it, so it will only be available in the _all field. The other fields map to their respective metadata names, but there is no need to specify the type (like string or date) since it is already known.
date 域 已经暴露了自己的string类型身份
The plugin uses Apache Tika to parse attachments, so many formats are supported, listed here.
