如何使用 Spring 正确连接到 MongoDB？

Question

我是春天的初学者。 我想创建连接到 MongoDB 的简单 Spring 应用程序。 我使用 Spring Initializer 生成了 Spring Boot，并按照指南创建了必要的文件。

MongoDB 正在运行。 当我运行该应用程序时，出现以下错误：

SpringFramework 2.2.0 M3 MongoDB 4.0 依赖项（在 Spring Initializer 中选择）：Web、MongoDB

数据库配置.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

我相信答案的关键在于堆栈跟踪的末尾，它说：

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

检查MongoClients.create方法中传递的host + ":" + port是否以mongodb://或mongodb+srv://开头。 通过查看您发布的内容，我无法确定host值是什么。

Answer 2

如果您不确定 mongodb uri，只需从 application.properties 中删除“spring.data.mongodb.uri”属性。 它应该工作。

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**

}

：：解决方案：：

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，您无需显式配置 MongoDB 连接。 在application.properties ，您只需要在 config 下面设置（使用 MongoDB 在本地）

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