我刚刚开始使用 C++ 并且正在学习如何使用 QT creator 作为 IDE，所以我怀疑这可能真的很容易，但我可能会遗漏一些东西。我安装了 apollo MQ 并安装了 apache CMS（C++ 消息服务），所以我可以用 C++ 与服务器交互。问题是，我不知道自己在做什么:-)（还），并且不确定为什么在使用示例时会出现上述错误。
我很确定这些示例很好，因为它们包含在源代码的示例文件夹中，所以它让我怀疑项目的配置不正确（因为它是我真正有影响的唯一因素）。
这是 .pro 文件：
TEMPLATE = app
CONFIG += console
CONFIG -= qt
SOURCES += main.cpp
INCLUDEPATH += /usr/local/include/activemq-cpp-3.4.2/
INCLUDEPATH += /opt/local/lib/
这是我指向的文件夹内容（我想要的文件都在那里的子目录中）：
drwxr-xr-x 13 root admin 442 May 11 19:09 activemq
drwxr-xr-x 48 root admin 1632 May 11 19:09 cms
drwxr-xr-x 9 root admin 306 May 11 19:09 decaf
这是我得到的错误：
20:54:22: Running build steps for project stackexchangeexample...
20:54:22: Configuration unchanged, skipping qmake step.
20:54:22: Starting: "/usr/bin/make" -w
make: Entering directory `/Users/lostsoul/Dropbox/qt_cuda/stackexchangeexample-build-desktop-Desktop_Qt_4_8_1_for_GCC__Qt_SDK__Debug'
/Users/lostsoul/QtSDK/Desktop/Qt/4.8.1/gcc/bin/qmake -spec ../../../QtSDK/Desktop/Qt/4.8.1/gcc/mkspecs/macx-g++ CONFIG+=declarative_debug -o Makefile ../stackexchangeexample/stackexchangeexample.pro
make: Leaving directory `/Users/lostsoul/Dropbox/qt_cuda/stackexchangeexample-build-desktop-Desktop_Qt_4_8_1_for_GCC__Qt_SDK__Debug'
make: Entering directory `/Users/lostsoul/Dropbox/qt_cuda/stackexchangeexample-build-desktop-Desktop_Qt_4_8_1_for_GCC__Qt_SDK__Debug'
g++ -headerpad_max_install_names -arch x86_64 -Xarch_x86_64 -mmacosx-version-min=10.5 -o stackexchangeexample.app/Contents/MacOS/stackexchangeexample main.o
Undefined symbols for architecture x86_64:
"activemq::library::ActiveMQCPP::initializeLibrary()", referenced from:
_main in main.o
"activemq::library::ActiveMQCPP::shutdownLibrary()", referenced from:
_main in main.o
"activemq::core::ActiveMQConnectionFactory::ActiveMQConnectionFactory(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)", referenced from:
SimpleProducer::run() in main.o
"cms::CMSException::CMSException(cms::CMSException const&)", referenced from:
SimpleProducer::run() in main.o
"typeinfo for cms::CMSException", referenced from:
GCC_except_table15 in main.o
GCC_except_table16 in main.o
SimpleProducer::run() in main.o
"cms::CMSException::~CMSException()", referenced from:
SimpleProducer::run() in main.o
"decaf::lang::Thread::getId()", referenced from:
SimpleProducer::run() in main.o
"decaf::lang::Long::toString(long long)", referenced from:
SimpleProducer::run() in main.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
make: *** [stackexchangeexample.app/Contents/MacOS/stackexchangeexample] Error 1
make: Leaving directory `/Users/lostsoul/Dropbox/qt_cuda/stackexchangeexample-build-desktop-Desktop_Qt_4_8_1_for_GCC__Qt_SDK__Debug'
20:54:22: The process "/usr/bin/make" exited with code 2.
Error while building project stackexchangeexample (target: Desktop)
When executing build step 'Make'
如果它有帮助，这是我运行的代码（它可能对任何人都没有帮助，因为你需要安装一堆东西才能让它工作，但以防万一它有帮助）：
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <decaf/lang/Thread.h>
#include <decaf/lang/Runnable.h>
#include <decaf/util/concurrent/CountDownLatch.h>
#include <decaf/lang/Long.h>
#include <decaf/util/Date.h>
#include <activemq/core/ActiveMQConnectionFactory.h>
#include <activemq/util/Config.h>
#include <activemq/library/ActiveMQCPP.h>
#include <cms/Connection.h>
#include <cms/Session.h>
#include <cms/TextMessage.h>
#include <cms/BytesMessage.h>
#include <cms/MapMessage.h>
#include <cms/ExceptionListener.h>
#include <cms/MessageListener.h>
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <memory>
using namespace activemq;
using namespace activemq::core;
using namespace decaf;
using namespace decaf::lang;
using namespace decaf::util;
using namespace decaf::util::concurrent;
using namespace cms;
using namespace std;
////////////////////////////////////////////////////////////////////////////////
class SimpleProducer : public Runnable {
private:
Connection* connection;
Session* session;
Destination* destination;
MessageProducer* producer;
bool useTopic;
bool clientAck;
unsigned int numMessages;
std::string brokerURI;
std::string destURI;
private:
SimpleProducer( const SimpleProducer& );
SimpleProducer& operator= ( const SimpleProducer& );
public:
SimpleProducer( const std::string& brokerURI, unsigned int numMessages,
const std::string& destURI, bool useTopic = false, bool clientAck = false ) :
connection(NULL),
session(NULL),
destination(NULL),
producer(NULL),
useTopic(useTopic),
clientAck(clientAck),
numMessages(numMessages),
brokerURI(brokerURI),
destURI(destURI) {
}
virtual ~SimpleProducer(){
cleanup();
}
void close() {
this->cleanup();
}
virtual void run() {
try {
// Create a ConnectionFactory
auto_ptr<ActiveMQConnectionFactory> connectionFactory(
new ActiveMQConnectionFactory( brokerURI ) );
// Create a Connection
try{
connection = connectionFactory->createConnection();
connection->start();
} catch( CMSException& e ) {
e.printStackTrace();
throw e;
}
// Create a Session
if( clientAck ) {
session = connection->createSession( Session::CLIENT_ACKNOWLEDGE );
} else {
session = connection->createSession( Session::AUTO_ACKNOWLEDGE );
}
// Create the destination (Topic or Queue)
if( useTopic ) {
destination = session->createTopic( destURI );
} else {
destination = session->createQueue( destURI );
}
// Create a MessageProducer from the Session to the Topic or Queue
producer = session->createProducer( destination );
producer->setDeliveryMode( DeliveryMode::NON_PERSISTENT );
// Create the Thread Id String
string threadIdStr = Long::toString( Thread::getId() );
// Create a messages
string text = (string)"Hello world! from thread " + threadIdStr;
for( unsigned int ix=0; ix<numMessages; ++ix ){
TextMessage* message = session->createTextMessage( text );
message->setIntProperty( "Integer", ix );
// Tell the producer to send the message
printf( "Sent message #%d from thread %s\n", ix+1, threadIdStr.c_str() );
producer->send( message );
delete message;
}
}catch ( CMSException& e ) {
e.printStackTrace();
}
}
private:
void cleanup(){
// Destroy resources.
try{
if( destination != NULL ) delete destination;
}catch ( CMSException& e ) { e.printStackTrace(); }
destination = NULL;
try{
if( producer != NULL ) delete producer;
}catch ( CMSException& e ) { e.printStackTrace(); }
producer = NULL;
// Close open resources.
try{
if( session != NULL ) session->close();
if( connection != NULL ) connection->close();
}catch ( CMSException& e ) { e.printStackTrace(); }
try{
if( session != NULL ) delete session;
}catch ( CMSException& e ) { e.printStackTrace(); }
session = NULL;
try{
if( connection != NULL ) delete connection;
}catch ( CMSException& e ) { e.printStackTrace(); }
connection = NULL;
}
};
////////////////////////////////////////////////////////////////////////////////
int main(int argc AMQCPP_UNUSED, char* argv[] AMQCPP_UNUSED) {
activemq::library::ActiveMQCPP::initializeLibrary();
std::cout << "=====================================================\n";
std::cout << "Starting the example:" << std::endl;
std::cout << "-----------------------------------------------------\n";
// Set the URI to point to the IPAddress of your broker.
// add any optional params to the url to enable things like
// tightMarshalling or tcp logging etc. See the CMS web site for
// a full list of configuration options.
//
// http://activemq.apache.org/cms/
//
// Wire Format Options:
// =====================
// Use either stomp or openwire, the default ports are different for each
//
// Examples:
// tcp://127.0.0.1:61616 default to openwire
// tcp://127.0.0.1:61616?wireFormat=openwire same as above
// tcp://127.0.0.1:61613?wireFormat=stomp use stomp instead
//
std::string brokerURI =
"failover://(tcp://127.0.0.1:61616"
// "?wireFormat=openwire"
// "&connection.useAsyncSend=true"
// "&transport.commandTracingEnabled=true"
// "&transport.tcpTracingEnabled=true"
// "&wireFormat.tightEncodingEnabled=true"
")";
//============================================================
// Total number of messages for this producer to send.
//============================================================
unsigned int numMessages = 2000;
//============================================================
// This is the Destination Name and URI options. Use this to
// customize where the Producer produces, to have the producer
// use a topic or queue set the 'useTopics' flag.
//============================================================
std::string destURI = "TEST.FOO";
//============================================================
// set to true to use topics instead of queues
// Note in the code above that this causes createTopic or
// createQueue to be used in the producer.
//============================================================
bool useTopics = false;
// Create the producer and run it.
SimpleProducer producer( brokerURI, numMessages, destURI, useTopics );
// Publish the given number of Messages
producer.run();
// Before exiting we ensure that all CMS resources are closed.
producer.close();
std::cout << "-----------------------------------------------------\n";
std::cout << "Finished with the example." << std::endl;
std::cout << "=====================================================\n";
activemq::library::ActiveMQCPP::shutdownLibrary();
}
我刚刚创建了一个空的 c++ 项目，修改了 .pro 文件以包含库的路径，然后将代码复制/粘贴到 main.cpp 中。知道是什么原因造成的吗？以及如何防止它？