1 package org.clearsilver; 2 3 /** 4 * Loads the ClearSilver JNI library. 5 * 6 * <p>By default, it attempts to load the library 'clearsilver-jni' from the 7 * path specified in the 'java.library.path' system property.</p> 8 * 9 * <p>If this fails, the JVM exits with a code of 1. However, this strategy 10 * can be changed using {@link #setFailureCallback(Runnable)}.</p> 11 */ 12 public class JNI { 13 14 /** 15 * Failure callback strategy that writes a message to sysout, then calls 16 * System.exit(1). 17 */ 18 public static Runnable EXIT_JVM = new Runnable() { 19 public void run() { 20 System.out.println("Could not load '" + libraryName + "'"); 21 System.out.println("java.library.path = " 22 + System.getProperty("java.library.path")); 23 System.exit(1); 24 } 25 }; 26 27 /** 28 * Failure callback strategy that throws an UnsatisfiedLinkError, which 29 * should be caught be client code. 30 */ 31 public static Runnable THROW_ERROR = new Runnable() { 32 public void run() { 33 throw new UnsatisfiedLinkError("Could not load '" + libraryName + "'"); 34 } 35 }; 36 37 private static Runnable failureCallback = EXIT_JVM; 38 39 private static Object callbackLock = new Object(); 40 41 private static String libraryName = "clearsilver-jni"; 42 43 /** 44 * Attempts to load the ClearSilver JNI library. 45 * 46 * @see #setFailureCallback(Runnable) 47 */ 48 public static void loadLibrary() { 49 try { 50 System.loadLibrary(libraryName); 51 } catch (UnsatisfiedLinkError e) { 52 synchronized (callbackLock) { 53 if (failureCallback != null) { 54 failureCallback.run(); 55 } 56 } 57 } 58 } 59 60 /** 61 * Sets a callback for what should happen if the JNI library cannot 62 * be loaded. The default is {@link #EXIT_JVM}. 63 * 64 * @see #EXIT_JVM 65 * @see #THROW_ERROR 66 */ 67 public static void setFailureCallback(Runnable failureCallback) { 68 synchronized(callbackLock) { 69 JNI.failureCallback = failureCallback; 70 } 71 } 72 73 /** 74 * Set name of JNI library to load. Default is 'clearsilver-jni'. 75 */ 76 public static void setLibraryName(String libraryName) { 77 JNI.libraryName = libraryName; 78 } 79 80 }
