如何使用 Spring 正確連接到 MongoDB？

Question

我是春天的初學者。 我想創建連接到 MongoDB 的簡單 Spring 應用程序。 我使用 Spring Initializer 生成了 Spring Boot，並按照指南創建了必要的文件。

MongoDB 正在運行。 當我運行該應用程序時，出現以下錯誤：

SpringFramework 2.2.0 M3 MongoDB 4.0 依賴項（在 Spring Initializer 中選擇）：Web、MongoDB

數據庫配置.java

package com.talkingflashcards.server.TalkingFlashcards.config;

import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;

@EnableMongoRepositories(basePackages = "com.talkingflashcards.server.TalkingFlashcards.repository")

@Configuration
public class DatabaseConfiguration extends AbstractMongoClientConfiguration {

    @Value("${spring.data.mongodb.host}")
    private String host;

    @Value("${spring.data.mongodb.port}")
    private String port;

    @Value("${spring.data.mongodb.username}")
    private String username;

    @Value("${spring.data.mongodb.password}")
    private String password;

    @Value("${spring.data.mongodb.database}")
    private String database;

    @Override
    public MongoClient mongoClient() {
        return MongoClients.create(host + ":" + port);
    }

    @Override
    protected String getDatabaseName() {
        return database;
    }
}

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
    2019-05-29 23:52:19.955 ERROR 10144 --- [           main] o.s.boot.SpringApplication               : Application run failed

    org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoTemplate' defined in class path resource [com/talkingflashcards/server/TalkingFlashcards/config/DatabaseConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.core.MongoTemplate]: Factory method 'mongoTemplate' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/talkingflashcards/server/TalkingFlashcards/config/DatabaseConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is java.lang.IllegalArgumentException: The connection string is invalid. Connection strings must start with either 'mongodb://' or 'mongodb+srv://
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:638) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:468) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1325) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1164) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:868) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.2.0.M3.jar:2.2.0.M3]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:782) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:404) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:319) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1275) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1263) [spring-boot-2.2.0.M3.jar:2.2.0.M3]
        at com.talkingflashcards.server.TalkingFlashcards.TalkingFlashcardsApplication.main(TalkingFlashcardsApplication.java:14) [classes/:na]
    Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.core.MongoTemplate]: Factory method 'mongoTemplate' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/talkingflashcards/server/TalkingFlashcards/config/DatabaseConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is java.lang.IllegalArgumentException: The connection string is invalid. Connection strings must start with either 'mongodb://' or 'mongodb+srv://
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:633) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        ... 19 common frames omitted
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mongoDbFactory' defined in class path resource [com/talkingflashcards/server/TalkingFlashcards/config/DatabaseConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is java.lang.IllegalArgumentException: The connection string is invalid. Connection strings must start with either 'mongodb://' or 'mongodb+srv://
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:638) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:468) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1325) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1164) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.resolveBeanReference(ConfigurationClassEnhancer.java:394) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:366) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration$$EnhancerBySpringCGLIB$$7a79cc38.mongoDbFactory(<generated>) ~[classes/:na]
        at org.springframework.data.mongodb.config.AbstractMongoClientConfiguration.mongoTemplate(AbstractMongoClientConfiguration.java:58) ~[spring-data-mongodb-2.2.0.M4.jar:2.2.0.M4]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration$$EnhancerBySpringCGLIB$$7a79cc38.CGLIB$mongoTemplate$3(<generated>) ~[classes/:na]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration$$EnhancerBySpringCGLIB$$7a79cc38$$FastClassBySpringCGLIB$$5311e25d.invoke(<generated>) ~[classes/:na]
        at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration$$EnhancerBySpringCGLIB$$7a79cc38.mongoTemplate(<generated>) ~[classes/:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        ... 20 common frames omitted
    Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.mongodb.MongoDbFactory]: Factory method 'mongoDbFactory' threw exception; nested exception is java.lang.IllegalArgumentException: The connection string is invalid. Connection strings must start with either 'mongodb://' or 'mongodb+srv://
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:633) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        ... 43 common frames omitted
    Caused by: java.lang.IllegalArgumentException: The connection string is invalid. Connection strings must start with either 'mongodb://' or 'mongodb+srv://
        at com.mongodb.ConnectionString.<init>(ConnectionString.java:288) ~[mongodb-driver-core-3.11.0-beta3.jar:na]
        at com.mongodb.client.MongoClients.create(MongoClients.java:61) ~[mongodb-driver-3.11.0-beta3.jar:na]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration.mongoClient(DatabaseConfiguration.java:32) ~[classes/:na]
        at org.springframework.data.mongodb.config.AbstractMongoClientConfiguration.mongoDbFactory(AbstractMongoClientConfiguration.java:71) ~[spring-data-mongodb-2.2.0.M4.jar:2.2.0.M4]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration$$EnhancerBySpringCGLIB$$7a79cc38.CGLIB$mongoDbFactory$2(<generated>) ~[classes/:na]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration$$EnhancerBySpringCGLIB$$7a79cc38$$FastClassBySpringCGLIB$$5311e25d.invoke(<generated>) ~[classes/:na]
        at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.2.0.M2.jar:5.2.0.M2]
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363) ~[spring-context-5.2.0.M2.jar:5.2.0.M2]
        at com.talkingflashcards.server.TalkingFlashcards.config.DatabaseConfiguration$$EnhancerBySpringCGLIB$$7a79cc38.mongoDbFactory(<generated>) ~[classes/:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.0.M2.jar:5.2.0.M2]
        ... 44 common frames omitted

    Disconnected from the target VM, address: '127.0.0.1:60940', transport: 'socket'

    Process finished with exit code 1

Answer 1

我相信答案的關鍵在於堆棧跟蹤的末尾，它說：

java.lang.IllegalArgumentException: The connection string is invalid. Connection strings must start with either 'mongodb://' or 'mongodb+srv://'

檢查MongoClients.create方法中傳遞的host + ":" + port是否以mongodb://或mongodb+srv://開頭。 通過查看您發布的內容，我無法確定host值是什么。

Answer 2

如果您不確定 mongodb uri，只需從 application.properties 中刪除“spring.data.mongodb.uri”屬性。 它應該工作。

Answer 3

@Override
public MongoClient mongoClient() {
    return MongoClients.create(host + ":" + port); // Error
    // trying to connect to **localhost:27017** it should be of form 
    // **mongodb://localhost:27017/yourDB**

}

：：解決方案：：

package com.talkingflashcards.server.TalkingFlashcards.config;

import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;

@EnableMongoRepositories(basePackages = "com.talkingflashcards.server.TalkingFlashcards.repository")

@Configuration
public class DatabaseConfiguration extends AbstractMongoClientConfiguration {


@Value("${spring.data.mongodb.uri}")
public String mongoUri;

@Override
protected void configureClientSettings(MongoClientSettings.Builder builder) {
    // customization hook
    builder.applyConnectionString(new ConnectionString(mongoUri));
}

@Override
protected String getDatabaseName() {
    return database;
}

}

在 application.propeties 中指定 mongodb uri 如下：

spring.data.mongodb.uri=mongodb://username:password@localhost:27017/yourDB

Answer 4

使用 Spring Boot，您無需顯式配置 MongoDB 連接。 在application.properties ，您只需要在 config 下面設置（使用 MongoDB 在本地）

spring.data.mongodb.uri=mongodb://localhost:27017/yourDB