JNA 加载动态链接库工具

原理：简而言之就是把jar包中的动态库解压写到系统临时文件目录中去，然后在动态库的目录结构的要求进行加载

获取系统临时文件目录：System.out.println(System.getProperty("java.io.tmpdir"));

// 如果动态库有目录结构方面的要求，就提前判断目录是否存在
public static void main(String[] args) {
    String HCNetSDKCom = System.getProperty("java.io.tmpdir") + "HCNetSDKCom";
    System.out.println(HCNetSDKCom);
    File file = new File(HCNetSDKCom);
    if (!file.exists()) {
        file.mkdir();
    }
}

【DynamicParseUtil】

package com.netsdk.lib.utils;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.IOException;
import java.io.InputStream;
import java.util.*;

/**
 * 动态解析库
 */
public class DynamicParseUtil {
  private DynamicLibParseHandler handler;
  private SAXParserFactory saxParserFactory;
  private SAXParser saxParser;

  /**
   * 适配各系统动态库名称大小写不同,以及lib前缀造成的找不到库的问题
   *
   * @param currentSystem 当前系统:win64,win32,linux64,linux32,mac64
   * @param libName 动态库名称
   * @return
   */
  public String compareLibName(String currentSystem, String libName) {
    String dynamicLibName = libName;
    List<String> libs = handler.getLibsBySystem(currentSystem);
    if (currentSystem.equalsIgnoreCase("win64")) {
      return findLibs(libs, libName);
    }
    if (libName.startsWith("lib")) {
      dynamicLibName = libName.substring(3);
    }
    return findLibs(libs, dynamicLibName);
  }

  private String findLibs(List<String> libs, String libName) {
    for (String lib : libs) {
      if (libName.equalsIgnoreCase(lib)) {
        return lib;
      }
    }
    return "";
  }

  public List<String> getLibsSystem(String system) {
    return handler.getLibsBySystem(system);
  }

  private DynamicParseUtil() throws ParserConfigurationException {
    // 获取SAX分析器的工厂实例，专门负责创建SAXParser分析器
    saxParserFactory = SAXParserFactory.newInstance();
    // 获取SAXParser分析器的实例
    try {
      saxParser = saxParserFactory.newSAXParser();
      handler = new DynamicLibParseHandler();
    } catch (ParserConfigurationException | SAXException e) {
      throw new ParserConfigurationException();
    }
  }

  public DynamicParseUtil(InputStream inputSteam)
      throws ParserConfigurationException, IOException, SAXException {
    this();
    saxParser.parse(inputSteam, handler);
  }

  /** xml解析handler */
  private static class DynamicLibParseHandler extends DefaultHandler {
    private final HashMap<String, List<String>> dynamics = new HashMap<>();
    private final List<String> systems = Arrays.asList("win64", "win32", "linux64", "linux32", "mac64", "linuxARM");
    private String currentDynamicSystem;
    private List<String> libs;

    public List<String> getLibsBySystem(String system) {
      return dynamics.get(system);
    }

    @Override
    public void startDocument() throws SAXException {
      super.startDocument();
    }

    @Override
    public void startElement(String uri, String localName, String qName, Attributes attributes)
        throws SAXException {
      super.startElement(uri, localName, qName, attributes);
      if (systems.contains(qName)) {
        currentDynamicSystem = qName;
        if (libs == null) {
          libs = new ArrayList<>();
        }
      }
    }

    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
      super.endElement(uri, localName, qName);
      if (systems.contains(qName)) {
        // 保存到hashmap中
        dynamics.put(currentDynamicSystem, libs);
        // 清除libs
        libs = null;
      }
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
      super.characters(ch, start, length);
      String lib = new String(ch, start, length);
      if (!lib.trim().isEmpty()) {
        libs.add(lib);
      }
    }
  }
}

【LibraryLoad】

package com.jt.hk.utils;


import org.xml.sax.SAXException;

import javax.xml.parsers.ParserConfigurationException;
import java.io.*;

/**
 * @description 动态库加载
 */
public class LibraryLoad {
    private static final String ARCH_WINDOWS = "win";
    private static final String ARCH_LINUX = "linux";
    private static final String ARCH_MAC = "mac";
    private static final int PREFIX_64 = 64;
    private static final int PREFIX_32 = 32;
    private static final String PREFIX_ARM = "ARM";
    private static final String EXTERNAL_WIN = ".dll";
    private static final String EXTERNAL_LINUX = ".so";
    private static final String EXTERNAL_MAC = ".dylib";
    private static DynamicParseUtil dynamicParseUtil;
    /**
     * 当前读取的目录
     */
    private static String currentFold;
    /**
     * 动态库需要写入的目录
     */
    private static String EXTRACT_PATH = System.getProperty("java.io.tmpdir");

    private static boolean written = false;

    /**
     * 设置动态库写入的路径,适用于需要自定义加载路径的用户
     *
     * @param path 动态库写入的文件夹,从该文件夹下加载sdk的动态库
     */
    public static void setExtractPath(String path) {
        EXTRACT_PATH = path;
    }

    /**
     * 动态库路径
     */
    private static String INNER_PATH;

    // private static final String EXTERNAL_MAC = ".so";

    private static String extractNetSDKLib(String libName) {
        return extractLibrary(libName);
    }

    public static String getLoadLibrary(String libraryName) {
        currentFold = getLibraryFold();
        if (dynamicParseUtil == null) {
            try {
                dynamicParseUtil =
                        new DynamicParseUtil(
                                LibraryLoad.class.getClassLoader().getResourceAsStream("dynamic-lib-load.xml"));
                if (!written) {
                    for (String libName : dynamicParseUtil.getLibsSystem(currentFold)) {
                        extractLibrary(libName);
                    }
                    written = true;
                }
            } catch (ParserConfigurationException | IOException | SAXException e) {
                e.printStackTrace();
            }
        }
        String fullName = getLibraryName(libraryName);
        String path = EXTRACT_PATH;
        if (!(EXTRACT_PATH.endsWith("/") || EXTRACT_PATH.endsWith("\\"))) {
            path = EXTRACT_PATH + "/";
        }
        System.out.println("加载外部函数库: " + path + fullName);
        return path + fullName;
    }

    /**
     * 将jar包里的动态库写入到系统缓存目录,使用绝对路径加载动态库
     *
     * @param libName
     * @return
     */
    private static String extractLibrary(String libName) {
        return extractLibrary("", libName);
    }

    /**
     * 相对路径文件夹
     *
     * @param relativePath 相对路径
     * @param libName      动态库路径
     * @return
     */
    private static String extractLibrary(String relativePath, String libName) {
        if (libName.trim().equals("")) {
            return "";
        }
        String libFullName = getLibraryName(libName);
        String dir = getLibraryFold();
        if (!(relativePath.endsWith("/") || relativePath.endsWith("\\"))) {
            relativePath = relativePath + "/";
        }
        String fileName = relativePath + dir + "/" + libFullName;
        InputStream in = LibraryLoad.class.getResourceAsStream(fileName);
        BufferedInputStream reader;
        FileOutputStream writer;
        File extractedLibFile = null;
        try {
            if (in == null) {
                in = new FileInputStream(fileName);
                if (in == null) {
                    return "";
                }
            }
            String nativeTempDir = EXTRACT_PATH;
            if (!(nativeTempDir.endsWith("/") || nativeTempDir.endsWith("\\"))) {
                nativeTempDir = nativeTempDir + "/";
            }
            extractedLibFile = new File(nativeTempDir + libFullName);
            reader = new BufferedInputStream(in);
            writer = new FileOutputStream(extractedLibFile);
            byte[] buffer = new byte[1024];
            while (true) {
                int len = reader.read(buffer);
                if (len == 0 || len == -1) {
                    break;
                }
                writer.write(buffer, 0, len);
            }
            reader.close();
            writer.close();
            in.close();
        } catch (Exception e) {
            // System.out.println(
            //     "dynamic file[ "
            //         + fileName
            //         + " ] not found in project.please ensure you need this library.");
        }
        String res = extractedLibFile != null ? extractedLibFile.getAbsolutePath() : "";
        System.out.println("加载目标动态库的绝对路径为: >>>>>>> " + res);
        return res;
    }

    /**
     * 获取动态库完整名称
     *
     * @param libName
     * @return
     */
    private static String getLibraryName(String libName) {
        String dir = currentFold;
        String libPrefix = "";
        String libExtension = EXTERNAL_WIN;


        // 如果 dynamic-lib-load.xml 文件中写了扩展名，那么就不对扩展名做额外处理
        if (libName.contains(".")) {
            libExtension = "";
        }

        if (!dir.contains("win")) {
            libPrefix = "lib";
            if (dir.contains("linux")) {
                libExtension = EXTERNAL_LINUX;
            } else {
                // libExtension=".dylib";
                libExtension = EXTERNAL_MAC;
            }
        }
        libName = dynamicParseUtil.compareLibName(currentFold, libName);
        // 动态库以lib开头，则不添加lib前缀
        // 以lib开头的库则不添加lib前缀
        libName = (libName.startsWith("lib") ? "" : libPrefix) + libName + libExtension;
        System.out.println("获取 dynamic-lib-load.xml 中的 动态库名称为: >>>>>>> " + libName);
        return libName;
    }

    // 获取系统对应的动态库文件夹
    private static String getLibraryFold() {
        String osType;
        String osName = System.getProperty("os.name");
        if (osName.toLowerCase().startsWith("linux")) {
            osType = ARCH_LINUX;
        } else if (osName.toLowerCase().startsWith("mac")
                || osName.toLowerCase().startsWith("darwin")) {
            osType = ARCH_MAC;
        } else if (osName.toLowerCase().startsWith("windows")) {
            osType = ARCH_WINDOWS;
        } else {
            osType = "";
        }
        String arch = System.getProperty("os.arch");
        arch = arch.toLowerCase().trim();
        if ("i386".equals(arch) || "i686".equals(arch) || "x86".equals(arch)) {
            arch = PREFIX_32 + "";
        } else if ("x86_64".equals(arch) || "amd64".equals(arch)) {
            arch = PREFIX_64 + "";
        } else if (arch.startsWith("arm")) {
            arch = PREFIX_ARM + "";
        }
        System.out.println("获取系统对应平台及架构的对应匹配的动态库文件夹名称为: >>>>>>> " + osType + arch);
        return osType + arch;
    }
}

【dynamic-lib-load.xml】

<?xml version="1.0" encoding="UTF-8" ?>
<dynamic-lib>
    <win64> <!-- 这个是平台类型与架构，需要与resources目录保持一致才能正常匹配 -->
        <lib>AudioRender</lib>
        <lib>HCCore</lib>
        <lib>HCNetSDK</lib>
        <lib>hlog</lib>
        <lib>hpr</lib>
        <lib>libeay32</lib>
        <lib>PlayCtrl</lib>
        <lib>ssleay32</lib>
        <lib>SuperRender</lib>
        <lib>zlib1</lib>
        <!-- 带文件夹的写法 -->
        <lib>HCNetSDKCom/AnalyzeData.dll</lib>
        <lib>HCNetSDKCom/AudioIntercom.dll</lib>
        <lib>HCNetSDKCom/AudioRender.dll</lib>
        <lib>HCNetSDKCom/HCAlarm.dll</lib>
        <lib>HCNetSDKCom/HCAlarm.lib</lib>
        <lib>HCNetSDKCom/HCCoreDevCfg.dll</lib>
        <lib>HCNetSDKCom/HCDisplay.dll</lib>
        <lib>HCNetSDKCom/HCGeneralCfgMgr.dll</lib>
        <lib>HCNetSDKCom/HCGeneralCfgMgr.lib</lib>
        <lib>HCNetSDKCom/HCIndustry.dll</lib>
        <lib>HCNetSDKCom/HCPlayBack.dll</lib>
        <lib>HCNetSDKCom/HCPreview.dll</lib>
        <lib>HCNetSDKCom/HCPreview.lib</lib>
        <lib>HCNetSDKCom/HCVoiceTalk.dll</lib>
        <lib>HCNetSDKCom/libiconv2.dll</lib>
        <lib>HCNetSDKCom/OpenAL32.dll</lib>
        <lib>HCNetSDKCom/StreamTransClient.dll</lib>
        <lib>HCNetSDKCom/SystemTransform.dll</lib>
    </win64>
   
    <win32>
        <lib>avnetsdk</lib>
        <lib>dhconfigsdk</lib>
        <lib>dhnetsdk</lib>
        <lib>dhplay</lib>
        <lib>Infra</lib>
        <lib>ImageAlg</lib>
        <lib>StreamConvertor</lib>
        <lib>jninetsdk</lib>
    </win32>
    <linux64>
        <lib>avnetsdk</lib>
        <lib>dhnetsdk</lib>
        <lib>dhconfigsdk</lib>
        <lib>StreamConvertor</lib>
        <lib>jninetsdk</lib>
    </linux64>
    <linux32>
        <lib>avnetsdk</lib>
        <lib>dhconfigsdk</lib>
        <lib>dhnetsdk</lib>
        <lib>StreamConvertor</lib>
        <lib>jninetsdk</lib>
    </linux32>
    <mac64>
        <lib>avnetsdk</lib>
        <lib>dhnetsdk</lib>
        <lib>dhconfigsdk</lib>
        <lib>StreamConvertor</lib>
    </mac64>
</dynamic-lib>

使用

public interface NetSDKLib extends Library {

    NetSDKLib NETSDK_INSTANCE = Native.load(LibraryLoad.getLoadLibrary("dhnetsdk"), NetSDKLib.class);
     
    // 动态库的 jna 代码
    // ...
    // ...
}