MongoDB的增删改查

MongoDB操作指南

最新推荐文章于 2020-09-14 16:41:36 发布

转载最新推荐文章于 2020-09-14 16:41:36 发布 · 307 阅读

本文介绍了一个基于MongoDB API 3.2.0的Java应用程序，演示了如何连接MongoDB数据库并执行基本操作，如插入、查询、更新和删除文档。

如何安装mongodb，请参考http://blog.youkuaiyun.com/zpf336/article/details/50765789

注：此文基于mongoDb API 3.2.0进行的测试。

测试代码如下：

pom.xml文件

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation= "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0 </modelVersion>
<groupId>mongo </groupId>
<artifactId>mongodb </artifactId>
<version>0.0.1-SNAPSHOT </version>
<packaging>jar </packaging>
<name>mongodb </name>
<url>http://maven.apache.org </url>
<properties>
<project.build.sourceEncoding>UTF-8 </project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit </groupId>
<artifactId>junit </artifactId>
<version>4.12 </version>
<scope>test </scope>
</dependency>
<dependency>
<groupId>org.mongodb </groupId>
<artifactId>mongo-java-driver </artifactId>
<version>3.2.0 </version>
</dependency>
</dependencies>
</project>

MongoDb API 类：

package mongo.mongodb;
import java.util.ArrayList;
import java.util.List;
import org.bson.Document;
import org.bson.conversions.Bson;
import com.mongodb.MongoClient;
import com.mongodb.client.FindIterable;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.result.UpdateResult;
public class MongoDb {
private static MongoCollection<Document> collection;
/**
* 链接数据库
*
* @param databaseName
* 数据库名称
* @param collectionName
* 集合名称
* @param hostName
* 主机名
* @param port
* 端口号
*/
public static void connect(String databaseName, String collectionName,
String hostName, int port) {
@SuppressWarnings( "resource")
MongoClient client = new MongoClient(hostName, port);
MongoDatabase db = client.getDatabase(databaseName);
collection = db.getCollection(collectionName);
System.out.println(collection);
}
/**
* 插入一个文档
*
* @param document
* 文档
*/
public static void insert(Document document) {
collection.insertOne(document);
}
/**
* 查询所有文档
*
* @return 所有文档集合
*/
public static List<Document> findAll() {
List<Document> results = new ArrayList<Document>();
FindIterable<Document> iterables = collection.find();
MongoCursor<Document> cursor = iterables.iterator();
while (cursor.hasNext()) {
results.add(cursor.next());
}
return results;
}
/**
* 根据条件查询
*
* @param filter
* 查询条件 //注意Bson的几个实现类，BasicDBObject, BsonDocument,
* BsonDocumentWrapper, CommandResult, Document, RawBsonDocument
* @return 返回集合列表
*/
public static List<Document> findBy(Bson filter) {
List<Document> results = new ArrayList<Document>();
FindIterable<Document> iterables = collection.find(filter);
MongoCursor<Document> cursor = iterables.iterator();
while (cursor.hasNext()) {
results.add(cursor.next());
}
return results;
}
/**
* 更新查询到的第一个
*
* @param filter
* 查询条件
* @param update
* 更新文档
* @return 更新结果
*/
public static UpdateResult updateOne(Bson filter, Bson update) {
UpdateResult result = collection.updateOne(filter, update);
return result;
}
/**
* 更新查询到的所有的文档
*
* @param filter
* 查询条件
* @param update
* 更新文档
* @return 更新结果
*/
public static UpdateResult updateMany(Bson filter, Bson update) {
UpdateResult result = collection.updateMany(filter, update);
return result;
}
/**
* 更新一个文档, 结果是replacement是新文档，老文档完全被替换
*
* @param filter
* 查询条件
* @param replacement
* 跟新文档
*/
public static void replace(Bson filter, Document replacement) {
collection.replaceOne(filter, replacement);
}
/**
* 根据条件删除一个文档
*
* @param filter
* 查询条件
*/
public static void deleteOne(Bson filter) {
collection.deleteOne(filter);
}
/**
* 根据条件删除多个文档
*
* @param filter
* 查询条件
*/
public static void deleteMany(Bson filter) {
collection.deleteMany(filter);
}
}

测试类：

package mongo.mongodb;
import java.util.List;
import org.bson.Document;
import org.junit.Before;
import org.junit.Test;
import com.mongodb.client.result.UpdateResult;
public class MongoTest
{
@Before
public void before(){
MongoDb.connect( "test", "darren", "172.16.155.151", 27017);
}
@Test
public void testInsert(){
Document document = new Document();
document.append( "name", "wang").append( "gender", "female");
MongoDb.insert(document);
}
@Test
public void testFindAll(){
List<Document> results = MongoDb.findAll();
for(Document doc : results){
System.out.println(doc.toJson());
}
}
@Test
public void testFindBy(){
Document filter = new Document();
filter.append( "name", "li si");
List<Document> results = MongoDb.findBy(filter);
for(Document doc : results){
System.out.println(doc.toJson());
}
}
@Test
public void testUpdateOne(){
Document filter = new Document();
filter.append( "gender", "male");
//注意update文档里要包含"$set"字段
Document update = new Document();
update.append( "$set", new Document( "gender", "female"));
UpdateResult result = MongoDb.updateOne(filter, update);
System.out.println( "matched count = " + result.getMatchedCount());
}
@Test
public void testUpdateMany(){
Document filter = new Document();
filter.append( "gender", "female");
//注意update文档里要包含"$set"字段
Document update = new Document();
update.append( "$set", new Document( "gender", "male"));
UpdateResult result = MongoDb.updateMany(filter, update);
System.out.println( "matched count = " + result.getMatchedCount());
}
@Test
public void testReplace(){
Document filter = new Document();
filter.append( "name", "zhang");
//注意：更新文档时，不需要使用"$set"
Document replacement = new Document();
replacement.append( "value", 123);
MongoDb.replace(filter, replacement);
}
@Test
public void testDeleteOne(){
Document filter = new Document();
filter.append( "name", "li");
MongoDb.deleteOne(filter);
}
@Test
public void testDeleteMany(){
Document filter = new Document();
filter.append( "gender", "male");
MongoDb.deleteMany(filter);
}
}