如何将mongo查询转换为java代码

Question

我有一个复杂的javascript代码来查询来自mongo shell的数据。如何在没有太多努力的情况下获得这方面的java等价，我经历了很多教程，但似乎都需要付出巨大的努力才能从查询中获得相同的结果

var trendForDate = new Date('2016-01-08T18:30:00.000Z');
 var oneMonthBack = new Date(trendForDate.getTime() - 1000 * 60 * 60 * 24 * 31);
 var trendToDate = new Date(trendForDate.getTime() + 1000 * 60 * 60 * 24);
 var loyal = "loyal";
 var newCustomer = "newCustomer";
 var loyalLost = "loyalLost";
 var dormant = "dormant";
 var lost = "lost";
 var usersForOrderDate = db.order.find({
     "status": "DELIVERED",
     "orderDate.interval_start": {
         $gte: trendForDate,
         $lt: trendToDate
     }
 }).map(function(o) {
     return o.customer
 });
 db.order.mapReduce(function() {
     emit(this.customer, {
         count: 1,
         orderDate: this.orderDate.interval_start
     })
 }, function(key, values) {
     var sum = 0;
     var lastOrderDate;
     var category;
     values.forEach(function(value) {
         if (value['orderDate']) {
             lastOrderDate = value['orderDate'];
         } else {
             lastOrderDate = value['lastOrderDate'];
         }
         sum += value['count'];
     });
     if (sum >= 5 & lastOrderDate > oneMonthBack) {
         category = loyal;
     }
     if (sum <= 4 & sum >= 1 & lastOrderDate > oneMonthBack) {
         category = newCustomer;
     }
     if (sum >= 5 & lastOrderDate < oneMonthBack) {
         category = loyalLost;
     }
     if (sum <= 4 & sum > 1 & lastOrderDate < oneMonthBack) {
         category = dormant;
     }
     if (sum == 1 & lastOrderDate < oneMonthBack) {
         category = lost;
     }
     return {
         count: sum,
         lastOrderDate: lastOrderDate,
         category: category
     };
 }, {
     query: {
         status: "DELIVERED",
         "orderDate.interval_start": {
             $lt: trendForDate
         }
     },
     out: {
         merge: "customerTrend"
     },
     finalize: function(key, value) {
         if (value.count == 1) {
             value.category = lost;
         }
         return value;
     },
     scope: {
         oneMonthBack: oneMonthBack,
         trendDate: trendForDate,
         loyal: loyal,
         newCustomer: newCustomer,
         loyalLost: loyalLost,
         dormant: dormant,
         lost: lost
     }
 });
 print(trendForDate);
 print(trendToDate);
 db.customerTrend.aggregate([{
     $match: {
         _id: {
             $in: usersForOrderDate
         }
     }
 }, {
     $group: {
         "_id": "$value.category",
         "users": {
             $sum: 1
         }
     }
 }]);

编辑：

通过此查询，我得到如下输出

{ "_id" : "dormant", "users" : 7 }
{ "_id" : "lost", "users" : 9 }
{ "_id" : "newCustomer", "users" : 53 }
{ "_id" : "loyalLost", "users" : 23 }
{ "_id" : "loyal", "users" : 160 }

要为查询运行的示例文档

{ "_id" : ObjectId("546b1018e4b0ce7d5ee021ce"), "customer" : ObjectId("546b0fdde4b0ce7d5ee021cc"), "orderDate" : { "jodaType" : "org.joda.time.DateTime", "interval_start" : ISODate("2014-11-17T18:30:00Z"), "interval_end" : ISODate("2014-11-17T18:30:00Z"), "jodaField_zone" : "UTC", "time" : NumberLong("1416249000000"), "jodaField_dayOfMonth" : 17, "jodaField_hourOfDay" : 18, "jodaField_minuteOfHour" : 30, "jodaField_millisOfSecond" : 0, "jodaField_monthOfYear" : 11, "jodaField_year" : 2014 }, "status" : "DELIVERED" }
{ "_id" : ObjectId("546b6d87e4b0ce7d5ee021e0"), "customer" : ObjectId("545f64e7e4b07a0a501276db"), "orderDate" : { "jodaType" : "org.joda.time.DateTime", "interval_start" : ISODate("2014-11-17T18:30:00Z"), "interval_end" : ISODate("2014-11-17T18:30:00Z"), "jodaField_zone" : "UTC", "time" : NumberLong("1416249000000"), "jodaField_dayOfMonth" : 17, "jodaField_hourOfDay" : 18, "jodaField_minuteOfHour" : 30, "jodaField_millisOfSecond" : 0, "jodaField_monthOfYear" : 11, "jodaField_year" : 2014 }, "status" : "DELIVERED" }
{ "_id" : ObjectId("546c13e3e4b0ce7d5ee021f0"), "customer" : ObjectId("54696c64e4b07f3c07010b4a"), "orderDate" : { "jodaType" : "org.joda.time.DateTime", "interval_start" : ISODate("2014-11-18T18:30:00Z"), "interval_end" : ISODate("2014-11-18T18:30:00Z"), "jodaField_zone" : "UTC", "time" : NumberLong("1416335400000"), "jodaField_dayOfMonth" : 18, "jodaField_hourOfDay" : 18, "jodaField_minuteOfHour" : 30, "jodaField_millisOfSecond" : 0, "jodaField_monthOfYear" : 11, "jodaField_year" : 2014 }, "status" : "DELIVERED" }
{ "_id" : ObjectId("546c2357e4b0ce7d5ee021fb"), "customer" : ObjectId("546c2208e4b0ce7d5ee021f9"), "orderDate" : { "jodaType" : "org.joda.time.DateTime", "interval_start" : ISODate("2014-11-18T18:30:00Z"), "interval_end" : ISODate("2014-11-18T18:30:00Z"), "jodaField_zone" : "UTC", "time" : NumberLong("1416335400000"), "jodaField_dayOfMonth" : 18, "jodaField_hourOfDay" : 18, "jodaField_minuteOfHour" : 30, "jodaField_millisOfSecond" : 0, "jodaField_monthOfYear" : 11, "jodaField_year" : 2014 }, "status" : "DELIVERED" }
{ "_id" : ObjectId("54b0db4ee4b08e29cd9309e0"), "customer" : ObjectId("549e790fe4b09508addfcc34"), "orderDate" : { "jodaType" : "org.joda.time.DateTime", "interval_start" : ISODate("2015-01-09T18:30:00Z"), "interval_end" : ISODate("2015-01-09T18:30:00Z"), "jodaField_zone" : "UTC", "time" : NumberLong("1420828200000"), "jodaField_dayOfMonth" : 9, "jodaField_hourOfDay" : 18, "jodaField_minuteOfHour" : 30, "jodaField_millisOfSecond" : 0, "jodaField_monthOfYear" : 1, "jodaField_year" : 2015 }, "status" : "DELIVERED" }
.....