情景

项目中需要使用多个不同系统的mongodb，而常规下，在配置文件使用的自动配置方式无法满足业务。所以，自定义多数据源可以满足以下需求：

使用多个mongodb。
对mongodb的信息进行加密。

废话少说，直接上代码。

1. 导包

重点是：spring-boot-starter-data-mongodb包

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.xywei.springboot</groupId>
    <artifactId>demo-mongo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo-mongo</name>
    <description>Demo project for Spring Boot using mongoTemplate</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring-boot.version>2.6.7</spring-boot.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.7.17</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>31.1-jre</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.fastjson2</groupId>
            <artifactId>fastjson2</artifactId>
            <version>2.0.15</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring-boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

2. 添加自定义配置文件

server:
  port: 8090

mongodb:
  primary:
#    uri: 192.168.126.147:27017
    username: test1
    password: test1
    database: test1
    address:
      192.168.126.147: 27017
    serverSelectionTimeoutMs: 5000
    connectTimeoutMs: 3000
    maxSize: 100
    minSize: 3
    maxWaitTimeMs: 5000
    maxConnectionIdleTime: 300000
  admin:
#    uri: 192.168.126.147:27017
    username: admin
    password: admin
    database: admin
    address:
      192.168.126.147: 27017
    serverSelectionTimeoutMs: 5000
    connectTimeoutMs: 3000
    maxSize: 100
    minSize: 3
    maxWaitTimeMs: 5000
    maxConnectionIdleTime: 300000

3. 添加配置多数据源

3.1 AbstractMongoDbConfig.java，配置factory使用

方法1：

package com.xywei.springboot.demomongo.config.mongodb;

import com.mongodb.MongoClientSettings;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import lombok.Data;
import org.springframework.data.mongodb.MongoDatabaseFactory;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.SimpleMongoClientDatabaseFactory;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

@Data
public abstract class AbstractMongoDbConfig {
    private String uri;
    private String username;
    private String password;
    private String database;
    private Map<String, Integer> address;
    private long serverSelectionTimeoutMs;
    private int connectTimeoutMs;
    private int maxSize;
    private int minSize;
    private long maxWaitTimeMs;
    private long maxConnectionIdleTime;

    public MongoDatabaseFactory mongoDatabaseFactory() {
        List<ServerAddress> serverAddresses = new ArrayList<>();
        address.forEach((host, port) -> {
            ServerAddress serverAddress = new ServerAddress(host, port);
            serverAddresses.add(serverAddress);
        });
        MongoClientSettings settings = MongoClientSettings.builder()
                .applyToClusterSettings(builder -> {
                    builder.hosts(serverAddresses);
                    builder.serverSelectionTimeout(serverSelectionTimeoutMs, TimeUnit.MILLISECONDS);
                })
                .applyToSocketSettings(builder -> {
                    builder.connectTimeout(connectTimeoutMs, TimeUnit.MILLISECONDS);
                })
                .applyToConnectionPoolSettings(builder -> {
                    builder.maxSize(maxSize);
                    builder.minSize(minSize);
                    builder.maxWaitTime(maxWaitTimeMs, TimeUnit.MILLISECONDS);
                    builder.maxConnectionIdleTime(maxConnectionIdleTime, TimeUnit.MILLISECONDS);
                })
                .credential(MongoCredential.createCredential(username, database, password.toCharArray()))
                .build();
        MongoClient mongoClient = MongoClients.create(settings);
        return new SimpleMongoClientDatabaseFactory(mongoClient, database);
    }
    public abstract MongoTemplate getMongoTemplate();
}

方法2：

package com.xywei.springboot.demomongo.config.mongodb;

import lombok.Data;
import org.springframework.data.mongodb.MongoDatabaseFactory;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.SimpleMongoClientDatabaseFactory;

@Data
public abstract class AbstractMongoDbConfig {
    private String uri;
    private String username;
    private String password;
    private String database;
    public MongoDatabaseFactory mongoDatabaseFactory() {
        String connectionString = "mongodb://" + username + ":" + password+ "@"+ uri +"/" + database;
        return new SimpleMongoClientDatabaseFactory(connectionString);
    }
    public abstract MongoTemplate getMongoTemplate();
}

3.2 配置数据源1，MongoDbConfigAdmin.java

package com.xywei.springboot.demomongo.config.mongodb;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.mongodb.core.MongoTemplate;

@Configuration
@ConfigurationProperties("mongodb.admin")
public class MongoDbConfigAdmin extends AbstractMongoDbConfig{

    @Bean(name = "mongoTemplateAdmin")
    @Override
    public MongoTemplate getMongoTemplate() {
        return new MongoTemplate(mongoDatabaseFactory());
    }
}

3.3 配置数据源2，MongoDbConfigPrimary.java

package com.xywei.springboot.demomongo.config.mongodb;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.data.mongodb.core.MongoTemplate;

@Configuration
@ConfigurationProperties("mongodb.primary")
public class MongoDbConfigPrimary extends AbstractMongoDbConfig{

    @Primary
    @Bean(name = "mongoTemplatePrimary")
    @Override
    public MongoTemplate getMongoTemplate() {
        return new MongoTemplate(mongoDatabaseFactory());
    }
}

3.4 使用

package com.xywei.springboot.demomongo;

import com.xywei.springboot.demomongo.entity.MergeRequest;
import com.xywei.springboot.demomongo.entity.TestUser;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
public class TestController {
    @Resource(name = "mongoTemplatePrimary")
    private MongoTemplate mongoTemplatePrimary;

    @Resource(name = "mongoTemplateAdmin")
    private MongoTemplate mongoTemplateAdmin;

    @GetMapping("/pk")
    public MergeRequest testFind() {
        MergeRequest mergeRequest = mongoTemplatePrimary.findById("633d97d27b6fbe75860e4c21", MergeRequest.class);
        System.out.println(mergeRequest);
        return mergeRequest;
    }

    @GetMapping("/admin")
    public TestUser testFind2() {
        return mongoTemplateAdmin.findById("633e7b9ddf226efab809741b", TestUser.class);
    }
}