mongoDB 擷取最後插入的文檔的ObjectID/_id方法

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http://stackoverflow.com/questions/3338999/get-id-of-last-inserted-document-in-a-mongodb-w-java-driver
mongoDB api就可以實現，請仔細查看集合insert方法的原始碼   a.文檔插入後可以擷取到插入的文檔的ObjectID代碼：BasicDBObject doc = new BasicDBObject( "name", "Matt" );
collection.insert( doc );
ObjectId id = (ObjectId)doc.get( "_id" );  b.文檔插入之前，可以自己產生一個ObjectID，簡單的方法如下代碼：//It‘s safe to do

doc.set("_id", new ObjectId())
//if you look at driver code

if ( ensureID && id == null ){
    id = ObjectId.get();
    jo.put( "_id" , id );      
}

public static ObjectId get(){
    return new ObjectId();
}   參看文章連結：http://www.thebirdietoldme.com/userActions/thread/Question.aspx?id=3338999http://stackoverflow.com/questions/7720256/mongodb-getting-objectid-of-last-inserted-document-with-multiple-concurrent-wr

mongoDB 擷取最後插入的文檔的ObjectID/_id方法