如何使用Java建立MongoDB连接？ [英] How to check if MongoDB connection is established with Java?

问题描述

在我的应用程序中， MongoDB 3.2.4在自定义端口上运行，我想实现逻辑，我的应用程序将试图达到 MongoDB 在自定义端口，如果失败，它将使用默认的 27018 端口。

In my app, MongoDB 3.2.4 runs on a custom port, I want to implement logic where my app will try to reach MongoDB on a custom port and if it fails it will use the default 27018 port.

为了做到这一点，我使用以下代码：

In order to do that I use the following code:

String mongoClientURI = "mongodb://" + DB_SRV_USR + ":" + DB_SRV_PWD + "@" + DB_URL + ":" + DB_PORT_CUS + "/" + dbName;
MongoClientURI connectionString = new MongoClientURI(mongoClientURI);

// enable SSL connection
MongoClientOptions.builder().sslEnabled(true).build();

if (this.mongoClient == null) {
    this.mongoClient = new MongoClient(connectionString);
}

// create database if doesn't exist
MongoDatabase mdb = this.mongoClient.getDatabase(dbName);

try {
    this.mongoClient.getAddress();
} catch (com.mongodb.MongoSocketOpenException e) {
    System.out.println("Switch to default port");
    /*…use default port logic…*/
}

是这个例外没有被抓住。
虽然 MongoDB 抛出以下异常：

The problem is that this exception is not caught. Although MongoDB throws the following exception:

com.mongodb。 MongoSocketOpenException：
com.mongodb.connection.SocketStream.open（SocketStream.java:63）的异常打开套接字
com.mongodb.connection.InternalStreamConnection.open（InternalStreamConnection.java:114）
在
com.mongodb.connection.DefaultServerMonitor $ ServerMonitorRunnable.run（DefaultServerMonitor.java:128）
在java.lang.Thread.run（Thread.java:745）导致：
java.net.ConnectException：连接拒绝：connect at
java.net.DualStackPlainSocketImpl.waitForConnect（Native Method）at
java.net.DualStackPlainSocketImpl.socketConnect（DualStackPlainSocketImpl.java:85）
at
java.net.AbstractPlainSocketImpl.doConnect（AbstractPlainSocketImpl.java:350）
at
java.net.AbstractPlainSocketImpl.connectToAddress（AbstractPlainSocketImpl.java:206）
at
java.net.AbstractPlainS ocketImpl.connect（AbstractPlainSocketImpl.java:188）
在java.net.PlainSocketImpl.connect（PlainSocketImpl.java:172）at
java.net.SocksSocketImpl.connect（SocksSocketImpl.java:392）at
java.net.Socket.connect（Socket.java:589）at
com.mongodb.connection.SocketStreamHelper.initialize（SocketStreamHelper.java:50）
at com.mongodb.connection.SocketStream .open（SocketStream.java:58）
... 3更多

com.mongodb.MongoSocketOpenException: Exception opening socket at com.mongodb.connection.SocketStream.open(SocketStream.java:63) at com.mongodb.connection.InternalStreamConnection.open(InternalStreamConnection.java:114) at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:128) at java.lang.Thread.run(Thread.java:745) Caused by: java.net.ConnectException: Connection refused: connect at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:589) at com.mongodb.connection.SocketStreamHelper.initialize(SocketStreamHelper.java:50) at com.mongodb.connection.SocketStream.open(SocketStream.java:58) ... 3 more

我的 catch 表达式无法捕获此异常。

my try-catch expression can't catch this exception.

我尝试了多种方法，例如：抓取：

I tried multiple approaches, such as to catch:

• 异常


• RuntimeException


• MongoSocketOpenException


• MongoException


• MongoCommandException

• Exception
• RuntimeException
• MongoSocketOpenException
• MongoException
• MongoCommandException

没有一个不起作用。

我的问题：

1. 如何检查 MongoDB 连接建立？


2. 如何捕获异常 MongoSocketOpenException ？<
   

1. How can I check if MongoDB connection is established?
2. How can catch the exception MongoSocketOpenException?

推荐答案

1. 我使用这段代码检查连接： / p>
   
   

1. I use this code to check connection:

try {
    mongo.getAddress();
} catch (Exception e) {
    System.out.println("Database unavailable!");
    mongo.close();
    return;
}

不确定这里我的猜测是 this.mongoClient.getAddress（）; 不会抛出该异常，但我不太了解

Not sure here my guess would be that this.mongoClient.getAddress(); does not throw that exception, but I don't really know

编辑：我初始化了：

Builder builder = MongoClientOptions.builder().connectTimeout(3000);  
MongoClient mongo = new MongoClient(new ServerAddress("192.168.0.1", 3000), builder.build());

这篇关于如何使用Java建立MongoDB连接？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！