我在一个交易引擎上工作，在运行时，我从engine.log得到日志，如下所示，
2018_01_02_03_28_20_684 INFO ZMQCommunicatorService REMOTE_EXECUTOR_MARKET_ADMIN-ALL_MARKETS-0-5 - no jzmq in java.library.path, sleeping 2 minutes then try again
2018_01_02_03_28_20_697 INFO ZMQCommunicatorService ENGINE_MARKET_ADMIN-ALL_MARKETS-0-4 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_30_20_696 INFO ZMQCommunicatorService REMOTE_EXECUTOR_MARKET_ADMIN-ALL_MARKETS-0-5 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_30_20_710 INFO ZMQCommunicatorService ENGINE_MARKET_ADMIN-ALL_MARKETS-0-4 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_32_20_697 INFO ZMQCommunicatorService REMOTE_EXECUTOR_MARKET_ADMIN-ALL_MARKETS-0-5 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_32_20_711 INFO ZMQCommunicatorService ENGINE_MARKET_ADMIN-ALL_MARKETS-0-4 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_34_20_698 INFO ZMQCommunicatorService REMOTE_EXECUTOR_MARKET_ADMIN-ALL_MARKETS-0-5 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_34_20_712 INFO ZMQCommunicatorService ENGINE_MARKET_ADMIN-ALL_MARKETS-0-4 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_36_20_699 INFO ZMQCommunicatorService REMOTE_EXECUTOR_MARKET_ADMIN-ALL_MARKETS-0-5 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
2018_01_02_03_36_20_713 INFO ZMQCommunicatorService ENGINE_MARKET_ADMIN-ALL_MARKETS-0-4 - Could not initialize class org.zeromq.ZMQ, sleeping 2 minutes then try again
我相信第一行讲述了主要问题，
No jzmq in java.library.path
我按照ZMQ binding for Java的安装手册，
cd /root
wget https://github.com/zeromq/jzmq/archive/v3.1.0.tar.gz -O jzmq-3.1.0.tar.gz
tar zxf jzmq-3.1.0.tar.gz
cd jzmq-3.1.0
./autogen.sh
./configure --prefix=/opt/jzmq-3.1.0
nice make
make install
加载项目后，需要在项目根目录中运行命令，
root@debian:~# export LD_LIBRARY_PATH=/opt/jzmq-3.1.0/lib
root@debian:~# java -Xss256k -cp /opt/jzmq-3.1.0/share/java/zmq.jar:draglet-common/target/lib/*:draglet-balser/target/lib/*:draglet-engine/target/lib/*:draglet-remote/target/lib/*:draglet-mapu/target/lib/*:draglet-shaba/target/lib/*:draglet-meba/target/lib/* -Dlog4j.configurationFile=draglet-common/src/main/resources/log4j2.xml -DisThreadContextMapInheritable=true com.draglet.batch.Batch draglet.yml
当时我得到的输出像，
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
Tue Jan 02 03:59:17 EST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
问题与Intellij终端提供的警告有什么关系吗？如何检查jzmq是否在java.library.path中？
在你的机器上看，如果这应该在应有的安装之后运行，或者不是：
最简单的形式原型之一是REQ/REP示例，它使用两个部分，一个 - “服务器”：
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.Context;
import org.zeromq.ZMQ.Socket;
public class rrserver{
public static void main (String[] args) {
Context context = ZMQ.context(1);
// Socket to talk to clients
Socket responder = context.socket(ZMQ.REP);
responder.bind("tcp://localhost:5560");
System.out.println("launch and connect server.");
while (!Thread.currentThread().isInterrupted()) {
// Wait for next request from client
byte[] request = responder.recv(0);
String string = new String(request);
System.out.println("Received request: ["+string+"].");
// Do some 'work'
try {
Thread.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Send reply back to client
responder.send("World".getBytes(), 0);
}
// We never get here but clean up anyhow
responder.close();
context.term();
}
}
另一部分是“客户”：
import org.zeromq.ZMQ;
import org.zeromq.ZMQ.Context;
import org.zeromq.ZMQ.Socket;
public class rrclient{
public static void main(String[] args) {
Context context = ZMQ.context(1);
// Socket to talk to server
Socket requester = context.socket(ZMQ.REQ);
requester.connect("tcp://localhost:5560"); // REF ABOVE AND LET START THIS AFTER "server"
System.out.println("launch and connect client.");
for (int request_nbr = 0; request_nbr < 10; request_nbr++) {
requester.send("Hello", 0);
String reply = requester.recvStr(0);
System.out.println("Received reply " + request_nbr + " [" + reply + "]");
}
// We never get here but clean up anyhow
requester.close();
context.term();
}
}
如果安装正确与否，这应该快速启动和运行。代码是借用ZeroMQ发布的琐碎案例来获取灵感的。
如果真的认真考虑进入分布式计算领域，请不要犹豫，阅读Pieter HINTJENS的一本好书，“Code Connected，Volume 1”（也可以pdf格式提供）。值得的时间和努力。
在OSX上我遇到了类似的问题。我安装了ZMQ using these instructions。
最后一步说用-Djava.library.path=/usr/local/lib设置库路径。
我发现简单地添加路径要容易得多
~/.bash_profile
例如：
echo "export JAVA_LIBRARY_PATH=$JAVA_LIBRARY_PATH:/usr/local/lib" >> ~/.bash_profile
重新启动Intellij后，它能够正确找到libjzmq。
如果您计划进行任何C / C ++开发，也可以导出DYLD_LIBRARY_PATH。
只需添加
export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:/usr/local/lib"
至
~/.bash_profile。