mondoDb java api 3.4 example

上代码吧

 

写道

import com.mongodb.Block;
import com.mongodb.client.AggregateIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoIterable;
import com.mongodb.client.model.Accumulators;
import com.mongodb.client.model.Aggregates;
import com.mongodb.client.model.Filters;
import com.mongodb.client.model.Projections;
import org.bson.Document;
import org.bson.conversions.Bson;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;


public class MongoDaoGroupQueryTest {
MongoCollection<Document> mc;

Block<Document> printBlock = document -> {
System.out.println("..start.....");
System.out.println(document.toJson());
//System.out.println("..gson.....");
//System.out.println(new Gson().toJson(document));
System.out.println("..end.....");
};

@Before
public void setUp() throws Exception {
//自适应 初始化mc
}



private void initData() {

//每次执行后清空集合以方便重复运行
mc.drop();
// title| owner | type| words | comments
// good day| tom |aaa |1|
// good | john|aaa|2
// good night| john|aaa|2
// happiness | tom|bbb|8
// a good thing | tom|aaa|16
//插入用于测试的文档
Document doc1 = new Document("title", "good day")
.append("owner", "tom")
.append("type", "aaa")
.append("words", 1)
.append("comments", Arrays.asList(
new Document("author", "joe").append("score", 3).append("comment", "good"),
new Document("author", "white").append("score", 1).append("comment", "oh no")
)
);
Document doc2 = new Document("title", "good")
.append("owner", "john")
.append("type", "aaa")
.append("words", 2)
.append("comments", Arrays.asList(
new Document("author", "william").append("score", 4).append("comment", "good"),
new Document("author", "white").append("score", 6).append("comment", "very good")
)
);
Document doc3 = new Document("title", "good night")
.append("owner", "mike")
.append("type", "bbb")
.append("words", 4)
.append("tag", Arrays.asList(1, 2, 3, 4));
Document doc4 = new Document("title", "happiness")
.append("owner", "tom")
.append("type", "bbb")
.append("words", 8)
.append("tag", Arrays.asList(2, 3, 4))
.append("comments", Arrays.asList(
new Document("author", "william").append("score", 10).append("comment", "haha")
)
);
Document doc5 = new Document("title", "a good thing")
.append("owner", "tom")
.append("type", "aaa")
.append("words", 16)
.append("tag", Arrays.asList(1, 2, 3, 4, 5));
mc.insertMany(Arrays.asList(doc1, doc2, doc3, doc4, doc5));
}

@Test
public void elemMatchTest() {
//嵌套内容的查询
Bson projection = Projections.elemMatch("comments", Filters.eq("author", "william"));
//BasicDBObject projection = new BasicDBObject(new BasicDBObject("statusLog",new BasicDBObject("$elemMatch",
// new BasicDBObject("status", "Submitted"))));
mc.find(projection).forEach(printBlock);
}

@Test
public void testGroup() throws Exception {
//简单聚合
//select owner, sum(words) as $words,count(*) as count, max(words),min(words),avg(words)
// from doc
// group by owner
AggregateIterable<Document> aggregate = mc.aggregate(Arrays.asList(
//Aggregates.match(Filters.exists("name")),
// Aggregates.project(new BasicDBObject("owner", "$owner")),
Aggregates.match(Filters.regex("title", "good")),
Aggregates.group("$owner",
//sum
Accumulators.sum("$words", "$words"),
//count
Accumulators.sum("count", 1),
//max
Accumulators.max("max", "$words"),
//min
Accumulators.min("min", "$words"),
//avg
Accumulators.avg("avg", "$words")
)
));
aggregate.forEach(printBlock);
/* 结果
{ "_id" : "mike", "totalWords" : 4, "count" : 1, "max" : 4, "min" : 4, "avg" : 4.0 }
{ "_id" : "john", "totalWords" : 2, "count" : 1, "max" : 2, "min" : 2, "avg" : 2.0 }
{ "_id" : "tom", "totalWords" : 17, "count" : 2, "max" : 16, "min" : 1, "avg" : 8.5 }
*/
}

@Test
public void testHaving() throws Exception {
//简单聚合
//select owner, sum(words) as $words,count(*) as count, max(words),min(words),avg(words)
// from doc
// where title='good'
// group by owner
AggregateIterable<Document> aggregate = mc.aggregate(Arrays.asList(
//Aggregates.match(Filters.exists("name")),
// Aggregates.project(new BasicDBObject("owner", "$owner")),
Aggregates.match(Filters.regex("title", "good")),
Aggregates.group("$owner",
//sum
Accumulators.sum("totalWords", "$words"),
//count
Accumulators.sum("count", 1)
),
// 其实这里就是一个流式处理, 前面的做完了,做后面的
//having totalWords>10
Aggregates.match(Filters.gt("totalWords", 10))

));
aggregate.forEach(printBlock);
/* 结果
{ "_id" : "tom", "totalWords" : 17, "count" : 2 }
*/
}

@Test
public void testGroupFilterInner() throws Exception {
//嵌套内容过滤的聚合
Bson projection = Projections.elemMatch("comments", Filters.eq("author", "william"));
AggregateIterable<Document> aggregate = mc.aggregate(Arrays.asList(
Aggregates.match(projection),
Aggregates.group("$owner", Accumulators.sum("totalWords", "$words"))
));
aggregate.forEach(printBlock);

}

@Test
public void testGroupByInner() throws Exception {
//基于嵌套内容的聚合
mc.aggregate(Arrays.asList(
//先分拆
Aggregates.unwind("$comments"),
//再聚合
Aggregates.group("$comments.author", Accumulators.sum("count", 1))
)).forEach(printBlock);
/* 结果:
{ "_id" : "william", "count" : 2 }
{ "_id" : "white", "count" : 2 }
{ "_id" : "joe", "count" : 1 }
*/
}

/**
* 多条件查询
*/
@Test
public void testCompoundQuery() throws Exception {
//select *
// from doc
// where owner='john' and word=20
mc.find(Filters.and(
Filters.eq("owner", "john"),
Filters.lt("word", 20)
)).forEach(printBlock);

}

@Test
public void testGroupMultiField() throws Exception {
//select owner,type,sum(words) as totalWords ,count(*)
// from doc
// group by owner,type
//多字段的聚合
Document groupFields = new Document()
.append("owner", "$owner")
.append("type", "$type");

AggregateIterable<Document> aggregate = mc.aggregate(Arrays.asList(
//过滤条件
//Aggregates.match(Filters.exists("name")),
//Aggregates.match(Filters.regex("title", "good")),
// Aggregates.project(new BasicDBObject("owner", "$owner")),
Aggregates.group(groupFields,
Accumulators.sum("totalWords", "$words")
, Accumulators.sum("count", 1))

));
aggregate.forEach(printBlock);

}



@Test
public void testGroupCountDistinct() throws Exception {
//SELECT COUNT(*) FROM (
// SELECT $owner,$type FROM ga_report_dict GROUP BY $owner,$type
//)a
Document groupFields = new Document()
.append("owner", "$owner")
.append("type", "$type");

AggregateIterable<Document> aggregate = mc.aggregate(
Arrays.asList(
Aggregates.group(groupFields),
Aggregates.group("_id", Accumulators.sum("count", 1))

)
);
aggregate.forEach(printBlock);
// 结果 : { "_id" : "_id", "count" : 4 }
}

}

 

吐槽:  iteye的代码自动格式化和高亮都做不到~~

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