因為今天開發遇到了性能問題，可能與MongoDB的連接配接有關，是以稍稍深入看了一下，正好搜到原來有人寫過這篇相關的内容，是以轉載過來。回頭有時間可以寫個擴充到SpringForAll裡，主體思路還是一樣的。感謝這位美女程式媛的文章！
https://blog.didispace.com/spring-boot-mongodb-connection-pool/#%E8%AF%B4%E6%98%8E 說明
Spring Boot中通過依賴
spring-boot-starter-data-mongodb
，來實作
spring-data-mongodb
的自動配置。
但是預設情況下，Spring Boot 中，并沒有像使用MySQL或者Redis一樣，提供了連接配接池配置的功能。是以，我們需要自行重寫
MongoDbFactory
，實作MongoDB用戶端連接配接的參數配置擴充。
需要說明的是，MongoDB的用戶端本身就是一個連接配接池，是以，我們隻需要配置用戶端即可。
https://blog.didispace.com/spring-boot-mongodb-connection-pool/#%E9%85%8D%E7%BD%AE%E6%96%87%E4%BB%B6 配置檔案
為了統一Spring Boot的配置，我們要将重寫的配置也配置到
application.yml
中，字首為
spring.data.mongodb.custom
下（字首可自己随意配置）：
spring:
data:
mongodb:
custom:
hosts:
- 10.0.5.1
- 10.0.5.1
ports:
- 27017
- 27018
replica-set: mgset-3590061
username: jancee
password: abc123
database: jancee
authentication-database: admin
connections-per-host: 20
min-connections-per-host: 20 該配置例子中，配置了副本集，其中包含了主機
10.0.5.1:27017
和
10.0.5.1:27018
，其它配置與Spring Boot的标準配置類似，另外，
connections-per-host
為用戶端的連接配接數，
in-connections-per-host
為用戶端最小連接配接數。
https://blog.didispace.com/spring-boot-mongodb-connection-pool/#%E5%B0%86%E9%85%8D%E7%BD%AE%E5%8C%85%E8%A3%85%E6%88%90%E7%B1%BB 将配置包裝成類
為友善調用和可讀性，将上述配置包裝成一個配置實體類，
MongoConfig.java
代碼如下:
|
package com.feidiao.jancee.fdiot.api.config.mongo;
import org.hibernate.validator.constraints.NotBlank;
import org.hibernate.validator.constraints.NotEmpty;
import org.springframework.stereotype.Component;
import org.springframework.validation.annotation.Validated;
import java.util.List;
@Component
@Validated
public class MongoSettingsProperties {
@NotBlank
private String database;
@NotEmpty
private List<String> hosts;
@NotEmpty
private List<Integer> ports;
private String replicaSet;
private String username;
private String password;
private String authenticationDatabase;
private Integer minConnectionsPerHost = 10;
private Integer connectionsPerHost = 2;
public MongoSettingsProperties() {
}
public String getDatabase() {
return database;
}
public void setDatabase(String database) {
this.database = database;
}
public List<String> getHosts() {
return hosts;
}
public void setHosts(List<String> hosts) {
this.hosts = hosts;
}
public List<Integer> getPorts() {
return ports;
}
public void setPorts(List<Integer> ports) {
this.ports = ports;
}
public String getReplicaSet() {
return replicaSet;
}
public void setReplicaSet(String replicaSet) {
this.replicaSet = replicaSet;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getAuthenticationDatabase() {
return authenticationDatabase;
}
public void setAuthenticationDatabase(String authenticationDatabase) {
this.authenticationDatabase = authenticationDatabase;
}
public Integer getMinConnectionsPerHost() {
return minConnectionsPerHost;
}
public void setMinConnectionsPerHost(Integer minConnectionsPerHost) {
this.minConnectionsPerHost = minConnectionsPerHost;
}
public Integer getConnectionsPerHost() {
return connectionsPerHost;
}
public void setConnectionsPerHost(Integer connectionsPerHost) {
this.connectionsPerHost = connectionsPerHost;
}
} 覆寫MongoDbFactory
接下來，就是覆寫Spring Boot原有的
MongoDbFactory
Bean，建立檔案
MongoConfig.java
，代碼如下：
import com.mongodb.MongoClient;
import com.mongodb.MongoClientOptions;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.MongoDbFactory;
import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
import java.util.ArrayList;
import java.util.List;
@Configuration
public class MongoConfig {
// 注入配置實體
@Autowired
private MongoSettingsProperties mongoSettingsProperties;
@Bean
@ConfigurationProperties(
prefix = "spring.data.mongodb.custom")
MongoSettingsProperties mongoSettingsProperties() {
return new MongoSettingsProperties();
}
// 覆寫預設的MongoDbFactory
@Bean
MongoDbFactory mongoDbFactory() {
//用戶端配置（連接配接數、副本叢集驗證）
MongoClientOptions.Builder builder = new MongoClientOptions.Builder();
builder.connectionsPerHost(mongoSettingsProperties.getConnectionsPerHost());
builder.minConnectionsPerHost(mongoSettingsProperties.getMinConnectionsPerHost());
if (mongoSettingsProperties.getReplicaSet() != null) {
builder.requiredReplicaSetName(mongoSettingsProperties.getReplicaSet());
}
MongoClientOptions mongoClientOptions = builder.build();
// MongoDB位址清單
List<ServerAddress> serverAddresses = new ArrayList<>();
for (String host : mongoSettingsProperties.getHosts()) {
Integer index = mongoSettingsProperties.getHosts().indexOf(host);
Integer port = mongoSettingsProperties.getPorts().get(index);
ServerAddress serverAddress = new ServerAddress(host, port);
serverAddresses.add(serverAddress);
}
System.out.println("serverAddresses:" + serverAddresses.toString());
// 連接配接認證
List<MongoCredential> mongoCredentialList = new ArrayList<>();
if (mongoSettingsProperties.getUsername() != null) {
mongoCredentialList.add(MongoCredential.createScramSha1Credential(
mongoSettingsProperties.getUsername(),
mongoSettingsProperties.getAuthenticationDatabase() != null ? mongoSettingsProperties.getAuthenticationDatabase() : mongoSettingsProperties.getDatabase(),
mongoSettingsProperties.getPassword().toCharArray()));
}
System.out.println("mongoCredentialList:" + mongoCredentialList.toString());
//建立用戶端和Factory
MongoClient mongoClient = new MongoClient(serverAddresses, mongoCredentialList, mongoClientOptions);
MongoDbFactory mongoDbFactory = new SimpleMongoDbFactory(mongoClient, mongoSettingsProperties.getDatabase());
return mongoDbFactory;
}
} 在這裡，實作了MongoDB連接配接時，前面配置的參數的設定，按照自己的實際情況，可以在
new SimpleMongoDbFactory
時，增加修改自己需要的配置參數。
至此，就完成了全部配置，運作測試即可。
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