为什么ElasticSearch批量API使用“content-type:application/json”头?

我只是想知道,如果请求的主体不是JSON,而是包含多行的文本(每个行都是JSON),那么ES为什么要使用这个头部。例如:

{ "create" : { "_index" : "movies", "_type" : "movie", "_id" : "135569" } }
{ "id": "135569", "title" : "Star Trek Beyond", "year":2016 , "genre":["Action", "Adventure", "Sci-Fi"] }
{ "create" : { "_index" : "movies", "_type" : "movie", "_id" : "122886" } }
{ "id": "122886", "title" : "Star Wars: Episode VII - The Force Awakens", "year":2015 , "genre":["Action", "Adventure", "Fantasy", "Sci-Fi", "IMAX"] }
{ "create" : { "_index" : "movies", "_type" : "movie", "_id" : "109487" } }
{ "id": "109487", "title" : "Interstellar", "year":2014 , "genre":["Sci-Fi", "IMAX"] }
{ "create" : { "_index" : "movies", "_type" : "movie", "_id" : "58559" } }
{ "id": "58559", "title" : "Dark Knight, The", "year":2008 , "genre":["Action", "Crime", "Drama", "IMAX"] }
{ "create" : { "_index" : "movies", "_type" : "movie", "_id" : "1924" } }
{ "id": "1924", "title" : "Plan 9 from Outer Space", "year":1959 , "genre":["Horror", "Sci-Fi"] }

这将是一个有效的请求,尽管它不是一个格式良好的JSON。在RESTful接口中,将某个东西定义为application/json(即使不是)是常见的吗?您甚至不能从邮递员那里发送它,只能从curl那里发送,curl不能验证body语法。