java - MongoSocketOpenException - 连接到 MongoDB 时出现问题

Question

这是我第一次尝试使用 MongoDB，所以如果你们有任何建议，我希望得到任何提示，但特别是，我在建立连接时遇到了困难...加载 jar 时会发生此错误。

这是我的堆栈跟踪:

[00:12:43 INFO]: Exception in monitor thread while connecting to server 127.0.0.1:27017
com.mongodb.MongoSocketOpenException: Exception opening socket
    at com.mongodb.connection.SocketStream.open(SocketStream.java:63) ~[GangWars-1.0-SNAPSHOT-shaded.jar:?]
    at com.mongodb.connection.InternalStreamConnection.open(InternalStreamConnection.java:115) ~[GangWars-1.0-SNAPSHOT-shaded.jar:?]
    at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:113) [GangWars-1.0-SNAPSHOT-shaded.jar:?]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_91]
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[?:1.8.0_91]
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source) ~[?:1.8.0_91]
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source) ~[?:1.8.0_91]
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source) ~[?:1.8.0_91]
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
    at java.net.PlainSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
    at java.net.SocksSocketImpl.connect(Unknown Source) ~[?:1.8.0_91]
    at java.net.Socket.connect(Unknown Source) ~[?:1.8.0_91]
    at com.mongodb.connection.SocketStreamHelper.initialize(SocketStreamHelper.java:57) ~[GangWars-1.0-SNAPSHOT-shaded.jar:?]
    at com.mongodb.connection.SocketStream.open(SocketStream.java:58) ~[GangWars-1.0-SNAPSHOT-shaded.jar:?]
    ... 3 more

这是我的代码(jar 运行时立即发生):

private void loadGangs() {
    MongoDB.getIDs().forEach(id -> GangUtils.addGang(new Gang(id)));
}

我的 MongoDB 类:

public final class MongoDB {

private static final String name = "data";
private static final MongoClient mongoClient = new MongoClient();

public static String getName() {
    return name;
}

public static MongoDatabase getDatabase() {
    return mongoClient.getDatabase(name);
}

public enum CollectionEnum {
    GANG, DRUGS, COPS
}

public static MongoCollection<Document> getCollection(CollectionEnum collection) {
    return getDatabase().getCollection(collection.name().toLowerCase());
}

public static List<Integer> getIDs() {
    List<Document> gangs = getCollection(CollectionEnum.GANG).find().into(new ArrayList<>());
    List<Integer> ids = new ArrayList<>();

    for (Document gang : gangs) {
        Object object = gang.get("_id");

        if (!(object instanceof Document)) continue;

        List<Document> idTags = (List<Document>) object;

        for (Document id : idTags) {
            ids.add(id.getInteger("_id"));
        }

    }

    return ids;
}

public static int getNextID() {
    int id = 0;
    for (int i = 0; i >= getIDs().size(); i++) {
        if (getIDs().get(i) != i) {
            id = i;
            break;
        }
        id++;
    }
    return id;
}

}

我做错了什么？ (我尝试在这里进行研究，但我找不到任何与 Java 相关的内容来帮助我使用 MongoDB)

Answer 1

我知道这篇文章有 9 个月的时间，但这可以帮助其他人。我遇到了同样的问题:问题是我不幸地将 test 作为 de.flapdoodle.embed.mongo 依赖项的 scope ，只需让它是默认(编译)通过注释范围解决了问题。

<dependency>
   <groupId>de.flapdoodle.embed</groupId>
   <artifactId>de.flapdoodle.embed.mongo</artifactId>
    <!-- <scope>test</scope>  -->
</dependency>

compile 是 maven 默认作用域。构建、测试和运行项目需要具有 compile 范围的依赖项。构建和运行项目不需要具有 test 范围的依赖项，而是编译和运行单元测试。因此，以 test 作为作用域的依赖项不会附加到构建过程的 jar/war 结果中，并且当我们运行项目时，所包含的类和其他资源不可用.
see here for more information about maven scopes