1 import proguard.annotation.*; 2 3 /** 4 * This application illustrates the use of annotations for configuring ProGuard. 5 * 6 * You can compile it with: 7 * javac -classpath ../lib/annotations.jar NativeCallBack.java 8 * You can then process it with: 9 * java -jar ../../../lib/proguard.jar @ ../examples.pro 10 * 11 * The annotation will preserve the class and its main method. 12 */ 13 @KeepApplication 14 public class NativeCallBack 15 { 16 /** 17 * Suppose this is a native method that computes an answer. 18 * 19 * The -keep option regular ProGuard configuration will make sure it is 20 * not renamed when processing this code. 21 */ 22 public native int computeAnswer(); 23 24 25 /** 26 * Suppose this method is called back from the above native method. 27 * 28 * ProGuard would remove it, because it is not referenced from java. 29 * The annotation will make sure it is preserved anyhow. 30 */ 31 @Keep 32 public int getAnswer() 33 { 34 return 42; 35 } 36 37 38 public static void main(String[] args) 39 { 40 int answer = new NativeCallBack().computeAnswer(); 41 42 System.out.println("The answer is " + answer); 43 } 44 } 45
