jni加载类库工具类

quding · quding · commit b4ce0fc59ec6 · 2017-02-20T18:54:03.000+08:00
diff --git a/Util-Demo/src/main/java/cn/mrdear/util/jniUtil/NativeLibraryLoader.java b/Util-Demo/src/main/java/cn/mrdear/util/jniUtil/NativeLibraryLoader.java
@@ -0,0 +1,54 @@
+package cn.mrdear.util.jniUtil;
+
+import java.io.*;
+
+/**
+ * Contains helper methods for loading native libraries, particularly JNI.
+ * 
+ * @author gkubisa
+ */
+public class NativeLibraryLoader {
+	/**
+	 * Utility classes should not have a public constructor.
+	 */
+	private NativeLibraryLoader() { }
+	
+	/**
+	 * Loads a native shared library. It tries the standard System.loadLibrary
+	 * method first and if it fails, it looks for the library in the current
+	 * class path. It will handle libraries packed within jar files, too.
+	 *
+	 * @param libraryName - name of the library to load
+	 * @throws IOException if the library cannot be extracted from a jar file
+	 * into a temporary file
+	 */
+	public static void loadLibrary(String libraryName) throws IOException {
+		try {
+			System.loadLibrary(libraryName);
+		} catch (UnsatisfiedLinkError e) {
+			String fileName = System.mapLibraryName(libraryName);
+
+			int dotPosition = fileName.lastIndexOf('.');
+			File file = File.createTempFile(fileName.substring(0, dotPosition), fileName.substring(dotPosition));
+			file.deleteOnExit();
+			
+			byte[] buffer = new byte[4096];
+			InputStream inputStream = NativeLibraryLoader.class.getClassLoader().getResourceAsStream(fileName);
+			OutputStream outputStream = new FileOutputStream(file);
+			
+			try {
+				while ( inputStream.available() > 0 ) {
+					int StreamLength = inputStream.read(buffer);
+					if ( StreamLength >= 0 ) {
+						outputStream.write(buffer, 0, StreamLength);
+					}
+				}
+			} finally {
+				outputStream.close();
+				inputStream.close();
+			}
+			
+			System.load(file.getAbsolutePath());
+		}
+	}
+}
