| 1 | package com.hammurapi.common; |
| 2 | |
| 3 | import java.lang.reflect.InvocationHandler; |
| 4 | import java.lang.reflect.Method; |
| 5 | import java.lang.reflect.Proxy; |
| 6 | import java.util.Arrays; |
| 7 | import java.util.LinkedList; |
| 8 | import java.util.List; |
| 9 | |
| 10 | /** |
| 11 | * This class creates a proxy which record all invocations of |
| 12 | * the methods of the target object with stack traces, calling threads, timestamps, and arguments. |
| 13 | * These records can be used for troubleshooing of concurrency problems. |
| 14 | * @author Pavel Vlasov |
| 15 | * |
| 16 | */ |
| 17 | public class InvocationRecordingProxyFactory { |
| 18 | |
| 19 | /** |
| 20 | * Callback interface to receive problem notifications. |
| 21 | * @author Pavel Vlasov |
| 22 | * |
| 23 | */ |
| 24 | public interface ProblemListener { |
| 25 | |
| 26 | void onProblem(Throwable th, List<InvocationRecord> records); |
| 27 | } |
| 28 | |
| 29 | public static class InvocationRecord { |
| 30 | |
| 31 | @Override |
| 32 | public String toString() { |
| 33 | return "InvocationRecord("+method.getName()+") [thread=" + thread + ", method=" + method |
| 34 | + ", timestamp=" + timestamp + ", arguments=" |
| 35 | + Arrays.toString(arguments) + ", target=" + target + "]"; |
| 36 | } |
| 37 | |
| 38 | private Thread thread; |
| 39 | private StackTraceElement[] stackTrace; |
| 40 | private Method method; |
| 41 | private long timestamp; |
| 42 | private Object[] arguments; |
| 43 | private Object target; |
| 44 | |
| 45 | InvocationRecord(Thread thread, StackTraceElement[] stackTrace, Method method, long timestamp, Object[] arguments, Object target) { |
| 46 | super(); |
| 47 | this.thread = thread; |
| 48 | this.stackTrace = stackTrace; |
| 49 | this.method = method; |
| 50 | this.timestamp = timestamp; |
| 51 | if (arguments != null) { |
| 52 | this.arguments = Arrays.copyOf(arguments, arguments.length); |
| 53 | } |
| 54 | this.target = target; |
| 55 | } |
| 56 | |
| 57 | public Thread getThread() { |
| 58 | return thread; |
| 59 | } |
| 60 | |
| 61 | public StackTraceElement[] getStackTrace() { |
| 62 | return stackTrace; |
| 63 | } |
| 64 | |
| 65 | public Method getMethod() { |
| 66 | return method; |
| 67 | } |
| 68 | |
| 69 | public long getTimestamp() { |
| 70 | return timestamp; |
| 71 | } |
| 72 | |
| 73 | Object[] getArguments() { |
| 74 | return arguments; |
| 75 | } |
| 76 | |
| 77 | Object getTarget() { |
| 78 | return target; |
| 79 | } |
| 80 | |
| 81 | } |
| 82 | |
| 83 | private static class RecordingInvocationHandler implements InvocationHandler { |
| 84 | |
| 85 | private ProblemListener problemListener; |
| 86 | |
| 87 | RecordingInvocationHandler(Object target, ProblemListener problemListener, LinkedList<InvocationRecord> records) { |
| 88 | this.target = target; |
| 89 | this.problemListener = problemListener; |
| 90 | this.records = records; |
| 91 | } |
| 92 | |
| 93 | private Object target; |
| 94 | |
| 95 | private LinkedList<InvocationRecord> records; |
| 96 | |
| 97 | @Override |
| 98 | public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { |
| 99 | |
| 100 | try { |
| 101 | synchronized (records) { |
| 102 | Thread currentThread = Thread.currentThread(); |
| 103 | records.addFirst(new InvocationRecord(currentThread, currentThread.getStackTrace(), method, System.currentTimeMillis(), args, target)); |
| 104 | } |
| 105 | Object ret = method.invoke(target, args); |
| 106 | Class<?> returnType = method.getReturnType(); |
| 107 | if (returnType.isInterface()) { |
| 108 | return Proxy.newProxyInstance(returnType.getClass().getClassLoader(), new Class[] {returnType}, new RecordingInvocationHandler(ret, problemListener, records)); |
| 109 | } |
| 110 | return ret; |
| 111 | } catch (Throwable th) { |
| 112 | if (problemListener!=null) { |
| 113 | problemListener.onProblem(th, records); |
| 114 | } |
| 115 | throw th; |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | List<InvocationRecord> getRecords() { |
| 120 | return records; |
| 121 | } |
| 122 | |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Wraps target into a proxy for method call recording. |
| 127 | * @param <I> |
| 128 | * @param <T> |
| 129 | * @param target |
| 130 | * @param problemListener |
| 131 | * @return |
| 132 | */ |
| 133 | @SuppressWarnings("unchecked") |
| 134 | public static <I, T extends I> I wrap(Class<I> proxyType, T target, ProblemListener problemListener) { |
| 135 | return (I) Proxy.newProxyInstance(target.getClass().getClassLoader(), new Class[] {proxyType}, new RecordingInvocationHandler(target, problemListener, new LinkedList<InvocationRecord>())); |
| 136 | } |
| 137 | |
| 138 | public static List<InvocationRecord> getInvocationRecords(Object proxy) { |
| 139 | return ((RecordingInvocationHandler) Proxy.getInvocationHandler(proxy)).getRecords(); |
| 140 | } |
| 141 | |
| 142 | } |