Java constructs BSON data types

Java constructs BSON data types

• Integer/Fu Fu points

  Java BSON constructs integer/Fu Fu point types

  {a:123, B:3.14}bsonobject obj = new Basicbsonobject (); Obj.put ("a", 123); Obj.put ("B", 3.14);

• String

  Java BSON Construct String type

  {A: "hi"}bsonobject obj = new Basicbsonobject (); Obj.put ("A", "HI");

• Empty type

  Java BSON constructed null type

  {A:null}bsonobject obj = new Basicbsonobject (); Obj.put ("a", null);

• Object

  Java BSON Constructing nested object types

  {B:{a:1}}bsonobject subobj = new Basicbsonobject (); Subobj.put ("A", 1); Bsonobject obj = new Basicbsonobject (); Obj.put ("B", subobj);

• Array

  Java BSON using Org.bson.types.BasicBSONList to construct array types

  {A:[0,1,2]}bsonobject obj = new Basicbsonobject (); Bsonobject arr = new Basicbsonlist () Arr.put ("0", 0), Arr.put ("1", 1); Arr.put ("2", 2); Obj.put ("A", arr);

• Boolean

  Java BSON Constructs a Boolean type

  {a:true, B:false}bsonobject obj = new Basicbsonobject (); Obj.put ("A", true); Obj.put ("B", false);

• Object ID

  Java BSON uses org.bson.types.ObjectId to generate the "_id" field content for each record. Java BSON 12 bytes of ObjectId and database concepts-the database-document-Object ID section describes the object ID slightly different, currently, Java ObjectId 12-byte content consists of three parts: 4 bytes Accurate to the second timestamp, 4-byte system (physical machine) label The sequence number starting with a random number of 4 bytes. By default, the database generates a unique object ID for each record that has a field named "_id."

  Bsonobject obj = new Basicbsonobject () ObjectId id1 = new ObjectId (); ObjectId id2 = new ObjectId ("53BB5667C5D061D6F579D0BB "); Obj.put (" _id ", ID1);

• Regular expressions

  Java BSON uses Java.util.regex.Pattern to construct the regular expression data type.

  Bsonobject matcher = new Basicbsonobject (); Pattern obj = pattern.compile ("^2001", pattern.case_insensitive); Matcher.put ("Serial_num", obj); Bsonobject modifier = new Basicbsonobject ("$set", New Basicbsonobject ("Count", +); Cl.update (matcher, modifier, NULL );

  The above uses regular expressions to construct a matching condition that changes the contents of the Count field of a record with a serial number beginning with "2001" to "1000".Note: The above uses the Patten constructs the Bson Matcher, when uses the Matcher.tostring (), the content is:

  {"Serial_num": {"$options": "I", "$regex": "^2001"}}

  the same content can also be obtained by the following Bson constructs:

  Bsonobject matcher2 = new Basicbsonobject (); Bsonobject obj2 = new Basicbsonobject () obj2.put ("$regex", "^2001"), Obj2.put ("$options", "I"), Matcher2.put ("Serial_ Num ", OBJ2);

  However, the data type of the Matcher2 constructed by the latter is a normal object nesting type, not a regular expression type.

• Date

  Java BSON uses java.util.Date to construct date types.

  Bsonobject obj = new Basicbsonobject ();D ate now = new Date (); Obj.put ("Date", now);

• Binary

  Java BSON uses org.bson.types.Binary to construct a binary type.

  Bsonobject obj = new Basicbsonobject (); String str = "Hello world"; byte[] arr = str.getbytes (); Binary bindata = new binary (arr); Obj.put ("Bindata", bindata);

• Time stamp

  Java BSON uses Org.bson.types.BSONTimestamp to construct timestamp types.

  int sec = 1404189030; 2014-07-01 12:30:30bsonobject obj = new Basicbsonobject (); Bsontimestamp ts = new Bsontimestamp (sec, 0); Obj.put ("timestamp", TS);

Java constructs BSON data types