在Java中创建mongodb封顶的集合 [英] Creating a mongodb capped collection in java
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问题描述
我想从Java代码创建一个有上限的集合.我找到了通过JavaScript创建语法的语法,但是找不到Java的示例.
I want to create a capped collection from Java code. I found the syntax for creating it through JavaScript, but could not find an example for Java.
Mongo mongo = new Mongo("127.0.0.1");
DB db = mongo.getDB("mydbid");
DBCollection collection;
if (db.collectionExists("mycollection")) {
collection = db.getCollection("mycollection");
} else {
collection = /* ????? Create the collection ?????? */
}
}
推荐答案
使用DB.createCollection操作,然后指定具有上限作为参数的DBObject.然后,您可以指定 size 和 max ,以控制字节大小和最大文档数. MongoDB网站在封顶集合上有一个教程,它解释了所有选项,但缺少每个示例的示例驱动程序.
Use the DB.createCollection operation and then specify a DBObject that has capped as a parameter. You can then specify size and max in order to control the byte size and the maximum number of documents. The MongoDB site has a tutorial on capped collections that explains all the options, but is missing an example for each driver.
Mongo mongo = new Mongo("127.0.0.1");
DB db = mongo.getDB("mydbid");
DBCollection collection;
if (db.collectionExists("mycollection")) {
collection = db.getCollection("mycollection");
} else {
DBObject options = BasicDBObjectBuilder.start().add("capped", true).add("size", 2000000000l).get();
collection = db.createCollection("mycollection", options);
}
}
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