File Permissions and Environment Setup

Configure executable privileges for build scripts:

chmod u+x configure.sh
chmod -R 755 ./

Install the required compilation toolchani: automake 1.4.1, autoconf, libtool, and CMake. For CentOS environments, replace OpenJDK with the Oracle JDK.

Build System Fundamentals

CMake provides cross-platform project management, generating native Makefiles or IDE projects from CMakeLists.txt definitions. For Linux development, small projects may use hand-written Makefiles, while complex cross-platform codebases benefit from CMake's abstraction.

Core CMake Directives

cmake_minimum_required(VERSION 3.10)
project(GeometryParser)

aux_source_directory(. SRC_LIST)
add_subdirectory(math)

add_executable(ParserApp main.cpp)
target_link_libraries(ParserApp MathUtils)

Subdirectory library configuration:

aux_source_directory(. LIB_SOURCES)
add_library(MathUtils ${LIB_SOURCES})

Essential Variables

Variable	Purpose
CMAKE_SOURCE_DIR	Root project path containing top-level CMakeLists.txt
CMAKE_BINARY_DIR	Build output directory (typically ./build)
CMAKE_CXX_STANDARD	C++ standard enforcement (e.g., set(CMAKE_CXX_STANDARD 11))
CMAKE_BUILD_TYPE	Compilation mode (Release/Debug)

Execute compilation:

cmake -B build -S .
cmake --build build

Compiling Dependencies

JSON Processing Library

Retrieve jsoncpp 0.10.7 (newer versions may trigger hexfloat namespace errors on CentOS despite C++11 flags):

wget https://github.com/open-source-parsers/jsoncpp/archive/refs/tags/0.10.7.tar.gz
tar -xzf 0.10.7.tar.gz
cd jsoncpp-0.10.7/

Generate both static and shared libraries:

cmake -DCMAKE_BUILD_TYPE=Release \
      -DBUILD_STATIC_LIBS=ON \
      -DBUILD_SHARED_LIBS=ON \
      -DARCHIVE_INSTALL_DIR=. \
      -G "Unix Makefiles" .
make && make install

DWF Core Libraries

Establish the directory hierarchy under /opt/dwf-build/, placing gnu and src folders accordingly.

DWFCore Compilation:

cd /opt/dwf-build/develop/global/build/gnu/dwfcore
./init-build.sh  # Convert line endings with dos2unix if errors occur

cd ../../../src/dwfcore
CXX="g++ -std=c++11" ./configure --with-zlib=no --with-expat=no
make && make install

DWF Toolkit Compilation:

cd /opt/dwf-build/develop/global/build/gnu/dwftoolkit
./init-build.sh

cd ../../../src/dwf
CXX="g++ -std=c++11" ./configure --with-jpeg=no
make && make install

Copy artifacts to your project library path:

cp -r /usr/local/lib/* /opt/dwf-build/libs/

Project Build Configuration

Create a development structure with dev/ for sources, include/ for headers, and lib/ for third-party binaries.

CMakeLists.txt Structure

cmake_minimum_required(VERSION 3.23)
set(BASE_DIRECTORY "/opt/dwf-build")
project(dwfGeometryExtractor)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -g -Wall -fPIC \
    -Wno-unused-variable -lpthread -luuid -lz -ldl")

include_directories(${BASE_DIRECTORY}/include)
link_directories(${BASE_DIRECTORY}/lib)

aux_source_directory(${BASE_DIRECTORY}/dev SOURCE_FILES)

# Create shared library
add_library(dwfGeometryExtractor SHARED ${SOURCE_FILES})

# Link order matters: toolkit must precede core
target_link_libraries(dwfGeometryExtractor 
    libjsoncpp.so 
    libdwftk.so 
    libdwfcore.so
)

Note: When linking static libraries into shared objects, position-independent code (-fPIC) is required. If errors persist, switch to shared library dependencies exclusive.

Build commands:

mkdir release && cd release
cmake ..
make

Java Native Access Integration

While JNI requires strict header management, JNA provides flexible dynamic libray invocation.

Java Interface Definition

package com.example.dwf.adapter;

import com.sun.jna.Library;
import com.sun.jna.Native;

public class GeometryAdapter {
    public interface DwfLibrary extends Library {
        DwfLibrary INSTANCE = Native.load("dwfGeometryExtractor", DwfLibrary.class);
        int extractGeometry(String inputPath, String outputPath);
    }

    public synchronized int convertFile(String dwfPath, String jsonPath) {
        return DwfLibrary.INSTANCE.extractGeometry(dwfPath, jsonPath);
    }
}

C++ Export Declaration

extern "C" {
    int extract_geometry(const char* input_file, const char* output_file) {
        // Implementation logic
        return 0;
    }
}

Spring Boot Deployment

Place libdwfGeometryExtractor.so in resources/linux-x86-64/. The JNA loader automatically prepends lib and appends .so, so reference the library in Java without these prefixes.

Configure Maven to prevent .so compression:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-resources-plugin</artifactId>
            <configuration>
                <nonFilteredFileExtensions>
                    <nonFilteredFileExtension>so</nonFilteredFileExtension>
                </nonFilteredFileExtensions>
            </configuration>
        </plugin>
    </plugins>
</build>

System Diagnostics

Locate JDK installation:

echo $JAVA_HOME
# Alternative:
whereis java

Identify memory-intensive processes:

ps aux --sort=-%mem | head -n 11

Search for specific binaries:

find / -name "automake" -type f -ls 2>/dev/null

Troubleshooting HTTP Timeouts

Symptom: Model loading interrupted with HTTP 404 and java.io.IOException: Broken pipe.

Resolution: Increase Nginx proxy timeout thresholds:

proxy_read_timeout 300s;
proxy_connect_timeout 300s;
proxy_send_timeout 300s;

Additionally, extend gateway server timeout configurations to prevent upstream connection termination during lengthy extraction operations.