java操控MongoDB简单使用，以及如何使用jfinal操控MongoDB

1. jfinal使用时封装的插件类

   操控MongoDatabase的MongoDb类。

   public class MongoDb {
       private static MongoDatabase mongoDatabase;
   
       public static void setMongoDatabase(MongoDatabase mongoDatabase) {
           MongoDb.mongoDatabase = mongoDatabase;
       }
   
       public static MongoDatabase use() {
           return mongoDatabase;
       }
   
       public static MongoCollection<Document> getCollection(String collName) {
           return mongoDatabase.getCollection(collName);
       }
   }
   

   控制连接的MongoDbPlugin类。

   public class MongoDbPlugin implements IPlugin {
       private MongoClient client;
   
       public MongoDbPlugin(String host, int port, String database) {
           client = new MongoClient(host, port);
           MongoDb.setMongoDatabase(client.getDatabase(database));
       }
   
       public MongoDbPlugin(String database) {
           this("localhost", 27017, database);
       }
   
       @Override
       public boolean start() {
           return true;
       }
   
       @Override
       public boolean stop() {
           client.close();
           return true;
       }
   }
   

2. 简单使用(流式)

   1. 使用正则字符串过滤指定字段

      MongoDb.getCollection("new_exam")
          	.find(Filters.regex("main_teacher", regStr))
           	.iterator()
          	.forEachRemaining(doc -> {
                resTeacherSet.add(doc.getString("main_teacher"));
            });
      

      多个条件或并且再排序

      MongoDb.getCollection("new_exam")
          .find(Filters.or(
                              Filters.regex("main_teacher", regTeacherName),
                              Filters.regex("deputy_teacher", regTeacherName)))
                      .sort(Sorts.ascending("timestamp"))