Spring boot在添加mongo-java-driver maven依赖时尝试连接mongo

Question

我刚刚添加了：

    <dependency>
        <groupId>org.mongodb</groupId>
        <artifactId>mongo-java-driver</artifactId>
    </dependency>

到我的 Maven 春季启动项目。我也有这个测试：

/*
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 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
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 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * limitations under the License.
 */
package hello;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class GreetingControllerTests {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void noParamGreetingShouldReturnDefaultMessage() throws Exception {

        this.mockMvc.perform(get("/greeting")).andDo(print()).andExpect(status().isOk())
                .andExpect(jsonPath("$.content").value("Hello, World!"));
    }

    @Test
    public void paramGreetingShouldReturnTailoredMessage() throws Exception {

        this.mockMvc.perform(get("/greeting").param("name", "Spring Community"))
                .andDo(print()).andExpect(status().isOk())
                .andExpect(jsonPath("$.content").value("Hello, Spring Community!"));
    }

}

由于某种原因，当我使用 mvn clean package 构建项目时，spring boot 现在尝试连接到 mongodb：

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.1.7.RELEASE)

2019-10-11 20:36:58.418  INFO 14870 --- [           main] hello.GreetingControllerTests            : Starting GreetingControllerTests on user-ThinkPad-X390 with PID 14870 (started by user in /home/user/repos/frontend-backend/backend)
2019-10-11 20:36:58.423  INFO 14870 --- [           main] hello.GreetingControllerTests            : No active profile set, falling back to default profiles: default
2019-10-11 20:36:59.311  INFO 14870 --- [           main] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2019-10-11 20:36:59.565  INFO 14870 --- [           main] org.mongodb.driver.cluster               : Cluster created with settings {hosts=[localhost:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms', maxWaitQueueSize=500}
2019-10-11 20:36:59.591  INFO 14870 --- [localhost:27017] org.mongodb.driver.cluster               : Exception in monitor thread while connecting to server localhost:27017

com.mongodb.MongoSocketOpenException: Exception opening socket
    at com.mongodb.internal.connection.SocketStream.open(SocketStream.java:67) ~[mongo-java-driver-3.8.2.jar:na]
    at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:126) ~[mongo-java-driver-3.8.2.jar:na]
    at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:117) ~[mongo-java-driver-3.8.2.jar:na]
    at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]
Caused by: java.net.ConnectException: Connection refused (Connection refused)
    at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na]
    at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na]

如果我只是删除测试或 mongo 依赖，上述mongo 连接不会启动。

但是上面的测试中没有提到mongo，为什么spring会尝试启动mongo连接呢？

Answer 1

如果非要我一句话来回答，那是因为Springboot是自以为是的。一旦通过AutoConfiguration 类注意到您的pom 中的mongo 依赖项，它将尝试连接到mongo。

如果你想覆盖默认行为并告诉 Springboot 不要做 MongoAutoConfiguration 那么你可以这样做

@SpringBootApplication(exclude=MongoAutoConfiguration.class)
public class YourMainApplication {

    public static void main(String[] args) {
        SpringApplication.run(TestApplication.class, args);
    }
}

或者你可以在你的属性文件中使用这一行

spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration

如果您执行上述任一操作，那么它将从您的应用程序中排除 MongoAutoconfiguration（而不仅仅是从您的测试中）。这意味着当您启动应用程序时，您将无法访问 mongo（如果这是您想要的）。

由于SpringbootTest 注释加载了整个应用程序上下文，它会查找这个主应用程序类。如果您排除了一些自动配置，那么即使在您的测试中，它也会被排除。所以你不会有连接到 mongo 的问题。

如果您希望仅在测试中排除此自动配置（以便在运行您的应用程序时不会更改任何内容），您可以这样做

@TestPropertySource(properties=
{"spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration"})
@SpringBootTest
public class GreetingControllerTests {...}