全网首发：Linux自带opencv库的JAVA调用失败/java.lang.UnsatisfiedLinkError:libopencv_ml.so.405: 无法打开共享对象文件

Posted 2022-02-05 柳鲲鹏

　　本来以为，修改了rpath之后，问题就解决了。结果依然说库找不到（库在同目录下）。具体来说：

Exception in thread "main" java.lang.UnsatisfiedLinkError: /home/wuxi/eclipse-workspace/FontTest/lib-native/libopencv_java455.so: libopencv_ml.so.405: 无法打开共享对象文件: 没有那个文件或目录
	at java.lang.ClassLoader$NativeLibrary.load(Native Method)
	at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1934)
	at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1817)
	at java.lang.Runtime.load0(Runtime.java:810)
	at java.lang.System.load(System.java:1088)
	at taishan.OpenCVTest.<clinit>(OpenCVTest.java:49)

　　吾反复实验都不对，就是说找不到。怎么办？干脆吾自己加载吧。别说，错误马上不一样了。考虑到通用性，使用了一个技巧，通过双层双重循环来处理。终于成功。代码如下：

package taishan;

import java.io.File;
import java.util.LinkedList;
import java.util.List;

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;


public class OpenCVTest

	private final static String NATIVE_DIR="/home/wuxi/eclipse-workspace/FontTest/lib-native";
	
	private final static String LIB_PREFIX       = "libopencv_";
	private final static String LIB_SUFFIX_LINUX = "so";
	private final static String LIB_SUFFIX_MAC   = "dylib";
	
    private static boolean isOpenCVLoaded = false;;

    private static List<File> getOpenCVFiles(final String dirName)
    
    	if (dirName == null)
    	
    		return null;
    	
    	File dir = new File(dirName);
    	if (!dir.exists() || !dir.isDirectory())
    	
    		return null;
    	
    	
    	File[] files = dir.listFiles();
    	List<File> fileList = new LinkedList<File>();
    	for (File file : files)
    	
    		String name = file.getName();
    		if (name.startsWith(LIB_PREFIX) && name.endsWith(LIB_SUFFIX_LINUX))
    		
    			fileList.add(file);
    		
    	
    	return fileList;
    
    
    private static void loadNativeOpenCV(final String dirName)
    
    	if (isOpenCVLoaded)
    	
    		return;
    	
    	
    	List<File> fileList = getOpenCVFiles(dirName);
    	if (fileList == null || fileList.size() == 0)
    	
    		return;
    	
    	
    	while (fileList.size() > 0)
    	
    		int left = fileList.size();
    		for (int i=0; i<fileList.size(); i++)
    		
    			File file = fileList.get(i);
    			try
    			
    				System.load(file.getAbsolutePath());
    			
    			catch (java.lang.Throwable e)
    			
    				continue;
    			
    			
    			fileList.remove(i);
    			i--;
    		

    		System.out.println(left+" ? "+fileList.size());
    		//如果这次循环后，剩余个数跟上次一样，说明依赖库有问题，中断。
    		if (left == fileList.size())
    		
    			fileList.clear();
    			return;
    		
    	
    	
    	//如果libopencv_java.so在另外目录，需要单独加载
    	//System.load(Dir+"/"+"lib"+Core.Core.NATIVE_LIBRARY_NAME+"."+LIB_SUFFIX_LINUX);
    	isOpenCVLoaded = true;
    
    
    public static void main(String[] args)
    
    	loadNativeOpenCV(NATIVE_DIR);
    	
        Mat mat = Mat.eye(3, 3, CvType.CV_8UC1);
        System.out.println("mat = "+mat.dump());