在本章中,我们将学习如何设置和使用MongoDB JDBC驱动程序。
安装 MongoDB JDBC驱动程序
要在Java程序中使用MongoDB之前,需要确保在机器上设置了MongoDB JDBC驱动程序和Java。 可以在机器上检查Java环境可通过:Java教程。 现在,我们来看一下如何设置MongoDB JDBC驱动。
- 下载 mongo.jar(http://mongodb.github.io/mongo-java-driver/),确保下载最新版本。
- 将 mongo.jar 包含到类路径中。
连接到数据库
要连接数据库,需要指定数据库名称,如果数据库不存在,那么MongoDB会自动创建它。
使用 Eclipse 创建一个 Maven 工程 - MongoDBJDBC ,其目录结果如下所示 -
有关 pom.xml
文件的内容如下 -
<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>com.yiibai</groupId>
<artifactId>MongoDBJDBC</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>MongoDBJDBC</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>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongodb-driver</artifactId>
<version>3.4.2</version>
</dependency>
</dependencies>
<build>
<defaultGoal>compile</defaultGoal>
</build>
</project>
以下是连接到数据库的代码片段 -
package com.yiibai.MongoDBJDBC;
/**
* Hello world!
*
*/
import com.mongodb.MongoClient;
import com.mongodb.client.MongoDatabase;
public class App {
public static void main(String args[]) {
try {
// To connect to mongodb server
MongoClient mongoClient = new MongoClient("localhost", 27017);
// Now connect to your databases
MongoDatabase mgdb = mongoClient.getDatabase("mycol");
System.out.println("Connect to database successfully!");
System.out.println("MongoDatabase inof is : "+mgdb.getName());
// If MongoDB in secure mode, authentication is required.
// boolean auth = db.authenticate(myUserName, myPassword);
// System.out.println("Authentication: "+auth);
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
}
}
默认认证机制
String user; // the user name
String database; // the name of the database in which the user is defined
char[] password; // the password as a character array
// ...
MongoCredential credential = MongoCredential.createCredential(user, database, password);
MongoClient mongoClient = new MongoClient(new ServerAddress("host1", 27017),
Arrays.asList(credential));
或者使用连接字符串而不明确指定认证机制:
MongoClientURI uri = new MongoClientURI("mongodb://user1:pwd1@host1/?authSource=db1");
MongoClient mongoClient = new MongoClient(uri);
执行上面代码,得到以下结果 -
com.mongodb.diagnostics.logging.JULLogger log
信息: Cluster created with settings {hosts=[localhost:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms', maxWaitQueueSize=500}
Connect to database successfully!
MongoDatabase inof is : mycol
创建和列出集合
要创建集合,可使用 com.mongodb.DB
类的 createCollection()
方法。
以下是创建集合的代码片段 -
package com.yiibai.MongoDBJDBC;
import org.bson.Document;
import com.mongodb.DBCollection;
import com.mongodb.client.model.CreateCollectionOptions;
/**
* Hello world!
*
*/
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
public class CreateCollection {
public static void main(String args[]) {
try {
// To connect to mongodb server
MongoClient mongoClient = new MongoClient("localhost", 27017);
// Now connect to your databases
MongoDatabase database = mongoClient.getDatabase("test");
//database.createCollection("NewCollection",new CreateCollectionOptions().capped(true).sizeInBytes(0x100000));
MongoCollection<Document> coll = database.getCollection("myTestCollection");
System.out.println("Collection created successfully");
System.out.println("当前数据库中的所有集合是:");
for (String name : database.listCollectionNames()) {
System.out.println(name);
}
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
}
}
执行上面代码,得到以下结果 -
Collection created successfully
当前数据库中的所有集合是:
mycol
inventory
post
mycollection
newcollection
插入文档
要将文档插入到MongoDB中,使用com.mongodb.DBCollection
类的insertOne()
方法。
以下是插入文档的代码片段 -
package com.yiibai.MongoDBJDBC;
import java.util.Arrays;
import org.bson.Document;
import com.mongodb.BasicDBObject;
import com.mongodb.Block;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
/**
* Hello world!
*
*/
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.CreateCollectionOptions;
public class InsertDocument {
public static void main(String args[]) {
try {
// To connect to mongodb server
MongoClient mongoClient = new MongoClient("localhost", 27017);
// Now connect to your databases
MongoDatabase database = mongoClient.getDatabase("test");
// database.createCollection("NewCollection", new
// CreateCollectionOptions().capped(true).sizeInBytes(0x100000));
System.out.println("Collection created successfully");
System.out.println("当前数据库中的所有集合是:");
for (String name : database.listCollectionNames()) {
System.out.println(name);
}
MongoCollection coll = database.getCollection("mycol");
System.out.println("Collection mycol selected successfully");
MongoCollection<Document> collection = database.getCollection("mycol");
Document document = new Document("_id", 1999).append("title", "MongoDB Insert Demo")
.append("description","database")
.append("likes", 30)
.append("by", "yiibai point")
.append("url", "http://www.yiibai.com/mongodb/");
collection.insertOne(document);
collection.find().forEach(printBlock);
System.out.println("Document inserted successfully");
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
}
static Block<Document> printBlock = new Block<Document>() {
public void apply(final Document document) {
System.out.println(document.toJson());
}
};
}
执行上面代码,得到以下结果 -
NewCollection
mycol
inventory
post
Collection
mycollection
newcollection
Collection mycol selected successfully
{ "_id" : 123.0, "title" : "MongoDB Overview", "description" : "MongoDB is no sql database", "by" : "yiibai tutorials", "url" : "http://www.yiibai.com", "tags" : ["mongodb", "database", "NoSQL"], "likes" : 100.0 }
{ "_id" : 100.0, "title" : "MongoDB Overview", "description" : "MongoDB is no sql database", "by" : "yiibai tutorials", "url" : "http://www.yiibai.com", "tags" : ["mongodb", "database", "NoSQL"], "likes" : 100.0 }
{ "_id" : 1999, "title" : "MongoDB Insert Demo", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }
Document inserted successfully
如何插入多行?
Document doc1 = new Document("name", "Amarcord Pizzeria")
.append("contact", new Document("phone", "264-555-0193")
.append("email", "amarcord.pizzeria@example.net")
.append("location",Arrays.asList(-73.88502, 40.749556)))
.append("stars", 2)
.append("categories", Arrays.asList("Pizzeria", "Italian", "Pasta"));
Document doc2 = new Document("name", "Blue Coffee Bar")
.append("contact", new Document("phone", "604-555-0102")
.append("email", "bluecoffeebar@example.com")
.append("location",Arrays.asList(-73.97902, 40.8479556)))
.append("stars", 5)
.append("categories", Arrays.asList("Coffee", "Pastries"));
List<Document> documents = new ArrayList<Document>();
documents.add(doc1);
documents.add(doc2);
collection.insertMany(documents);
更新文档
要从集合更新文档,使用com.mongodb.DBCollection
类的update()
和updateMany()
方法。以下是选择第一个文档的代码片段 -
package com.yiibai.MongoDBJDBC;
import org.bson.Document;
import com.mongodb.Block;
/**
* Hello world!
*
*/
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoCollection;
import org.bson.Document;
import com.mongodb.client.MongoCursor;
import static com.mongodb.client.model.Filters.*;
import com.mongodb.client.result.DeleteResult;
import static com.mongodb.client.model.Updates.*;
import com.mongodb.client.result.UpdateResult;
import java.util.ArrayList;
import java.util.List;
public class App {
public static void main(String args[]) {
try {
// To connect to mongodb server
MongoClient mongoClient = new MongoClient("127.0.0.1", 27017);
// Now connect to your databases
MongoDatabase database = mongoClient.getDatabase("mycol");
System.out.println("Connect to database successfully!");
System.out.println("MongoDatabase inof is : "+database.getName());
MongoCollection<Document> collection = database.getCollection("mycol");
//collection.updateOne(eq("_id", 1999),new Document("$set", new Document("title", "更新了标题2")));
Document document = new Document("_id", 9999).append("title", "MongoDB Insert Demo")
.append("description","database")
.append("likes", 30)
.append("by", "yiibai point")
.append("url", "http://www.yiibai.com/mongodb/");
collection.insertOne(document);
collection.find().forEach(printBlock);
collection.updateOne(eq("_id", 9999),new Document("$set", new Document("title", "更新了标题2")));
collection.find().forEach(printBlock);
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
}
static Block<Document> printBlock = new Block<Document>() {
public void apply(final Document document) {
System.out.println(document.toJson());
}
};
}
执行上面代码,得到以下结果 -
{ "_id" : 1999, "title" : "更新了标题2", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }
{ "_id" : 9999, "title" : "MongoDB Insert Demo", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }
{ "_id" : 1999, "title" : "更新了标题2", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }
{ "_id" : 9999, "title" : "更新了标题2", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }
删除文档
要从集合中删除第一个文档,需要首先使用findOne()
方法选择文档,然后使用com.mongodb.DBCollection
类的remove()
方法。
以下是删除第一个文档的代码片段 -
package com.yiibai.MongoDBJDBC;
import org.bson.Document;
import com.mongodb.Block;
/**
* Hello world!
*
*/
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoCollection;
import org.bson.Document;
import com.mongodb.client.MongoCursor;
import static com.mongodb.client.model.Filters.*;
import com.mongodb.client.result.DeleteResult;
import static com.mongodb.client.model.Updates.*;
import com.mongodb.client.result.UpdateResult;
import java.util.ArrayList;
import java.util.List;
public class App {
public static void main(String args[]) {
try {
// To connect to mongodb server
MongoClient mongoClient = new MongoClient("127.0.0.1", 27017);
// Now connect to your databases
MongoDatabase database = mongoClient.getDatabase("mycol");
System.out.println("Connect to database successfully!");
System.out.println("MongoDatabase inof is : "+database.getName());
// 更新文档
MongoCollection<Document> collection = database.getCollection("mycol");
/**
Document document = new Document("_id", 9999).append("title", "MongoDB Insert Demo")
.append("description","database")
.append("likes", 30)
.append("by", "yiibai point")
.append("url", "http://www.yiibai.com/mongodb/");
collection.insertOne(document);
//collection.find().forEach(printBlock);
//collection.updateOne(eq("_id", 9999),new Document("$set", new Document("title", "更新了标题2")));
*/
collection.find().forEach(printBlock);
// 删除文档
collection.deleteOne(eq("_id", 9999));
System.out.println("After Delete Document:");
collection.find().forEach(printBlock);
} catch (Exception e) {
System.err.println(e.getClass().getName() + ": " + e.getMessage());
}
}
static Block<Document> printBlock = new Block<Document>() {
public void apply(final Document document) {
System.out.println(document.toJson());
}
};
}
执行上面代码,得到以下结果 -
{ "_id" : 1999, "title" : "更新了标题2", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }
{ "_id" : 9999, "title" : "更新了标题2", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }
After Delete Document:
{ "_id" : 1999, "title" : "更新了标题2", "description" : "database", "likes" : 30, "by" : "yiibai point", "url" : "http://www.yiibai.com/mongodb/" }