[log4cxx]: log4cxx: Can't cast writer to FileOutputStream

[MtZandy]

Hi, I am trying to implement a small binarie that rotates logs using multiprocessrollingfileappender.h in C++ std20, it should create a log and then rotate it every 0.8mb, I want to execute multiple mains and have the log as a shared resource.

OS: Ubuntu 22.04.5 LTS, 64-bit.

make file:

all:
    clear
    g++ -v main.cpp -o main -I/usr/local/include \
    -I. -I/usr/local/include/log4cxx -L./lib -L/usr/local/lib -llog4cxx -lrt -lpthread

all2:
    clear
    g++ main.cpp -o main -I/usr/local/include -L/usr/local/lib -llog4cxx -lrt -lpthread

clean:
    rm main

main.cpp:

#include <log4cxx/logger.h>
#include <log4cxx/propertyconfigurator.h>
#include <log4cxx/rolling/rollingfileappender.h>
#include <log4cxx/rolling/multiprocessrollingfileappender.h>

#include <iostream>
#include <thread>
#include <vector>
#include <chrono>
#include <unistd.h>
using namespace log4cxx;
using namespace log4cxx::rolling;

LoggerPtr logger(Logger::getLogger("multiprocessRollingFile"));

void logMessages(int threadId) {

   
   
    for (int i = 0; i < 10; ++i) {
        LOG4CXX_INFO(logger, "Thread " << threadId << " logging message " << i << " pid: "<< getpid());
       
    }
}

int main() {
    // Load configuration
    PropertyConfigurator::configure("/home/andy/Documents/Scripts/cpp/multi/log4cxx.properties");

    const int numThreads = 1;
    std::vector<std::thread> threads;

    for (int i = 0; i < numThreads; ++i) {
        threads.emplace_back(logMessages, i);
    }

    for (auto& t : threads) {
        t.join();
    }

    return 0;
}

propertiesfile:

log4j.rootLogger=DEBUG, multiprocessRollingFile

# Multiprocess RollingFileAppender
log4j.appender.multiprocessRollingFile=org.apache.log4cxx.rolling.MultiprocessRollingFileAppender
log4j.appender.multiprocessRollingFile.fileName=/home/andy/Documents/Scripts/cpp/multi/var/log/myapp.log

# Rolling Policy
log4j.appender.multiprocessRollingFile.rollingPolicy=org.apache.log4cxx.rolling.FixedWindowRollingPolicy
log4j.appender.multiprocessRollingFile.rollingPolicy.fileNamePattern=/home/andy/Documents/Scripts/cpp/multi/var/log/myapp.log.%i
log4j.appender.multiprocessRollingFile.rollingPolicy.minIndex=1
log4j.appender.multiprocessRollingFile.rollingPolicy.maxIndex=5

# Triggering Policy
log4j.appender.multiprocessRollingFile.triggeringPolicy=org.apache.log4cxx.rolling.SizeBasedTriggeringPolicy
log4j.appender.multiprocessRollingFile.triggeringPolicy.maxFileSize=0.8MB
log4j.appender.multiprocessRollingFile.MaxBackupIndex=200

# Layout
log4j.appender.multiprocessRollingFile.layout=org.apache.log4cxx.PatternLayout
log4j.appender.multiprocessRollingFile.layout.conversionPattern=%d [%t] %-5p %c - %m%n

I will really appreciate your help and support. Thanks in advance.

[swebb2066]

This issue was fixed in Log4cxx 1.4.0. You will need to build Log4cxx 1.4.0 yourself defining LOG4CXX_MULTIPROCESS_ROLLING_FILE_APPENDER=on as 1.4.0 will not yet be available in distribution releases.

[MtZandy]

What if is already turned to ON in the build file? it lets me compile the main file however when I run the program it pops that problem

[swebb2066]

What version of Log4cxx did you build?

[MtZandy]

I am using apache-log4cxx-1.3.1

[swebb2066]

This issue was fixed in 1.4.0. You need to swithc to 1.4.0.