1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License
15  */
16 
17 package com.android.compatibility.common.util;
18 
19 /**
20  * Helper methods for dealing with stack traces
21  */
22 public class Stacktrace {
23 
24     private static final int SAFETY_DEPTH = 4;
25     private static final String TEST_POSTFIX = "Test";
26 
Stacktrace()27     private Stacktrace() {}
28 
29     /**
30      * @return classname#methodname from call stack of the current thread
31      */
getTestCallerClassMethodName()32     public static String getTestCallerClassMethodName() {
33         return getTestCallerClassMethodName(false /*includeLineNumber*/);
34     }
35 
36     /**
37      * @return classname#methodname from call stack of the current thread
38      */
getTestCallerClassMethodNameLineNumber()39     public static String getTestCallerClassMethodNameLineNumber() {
40         return getTestCallerClassMethodName(true /*includeLineNumber*/);
41     }
42 
43     /**
44      * @return classname#methodname from call stack of the current thread
45      */
getTestCallerClassMethodName(boolean includeLineNumber)46     private static String getTestCallerClassMethodName(boolean includeLineNumber) {
47         StackTraceElement[] elements = Thread.currentThread().getStackTrace();
48         // Look for the first class name in the elements array that ends with Test
49         for (int i = 0; i < elements.length; i++) {
50             if (elements[i].getClassName().endsWith(TEST_POSTFIX)) {
51                 return buildClassMethodName(elements, i, includeLineNumber);
52             }
53         }
54 
55         // Use a reasonable default if the test name isn't found
56         return buildClassMethodName(elements, SAFETY_DEPTH, includeLineNumber);
57     }
58 
buildClassMethodName( StackTraceElement[] elements, int depth, boolean includeLineNumber)59     private static String buildClassMethodName(
60             StackTraceElement[] elements, int depth, boolean includeLineNumber) {
61         depth = Math.min(depth, elements.length - 1);
62         StringBuilder builder = new StringBuilder();
63         builder.append(elements[depth].getClassName()).append("#")
64                 .append(elements[depth].getMethodName());
65         if (includeLineNumber) {
66             builder.append(":").append(elements[depth].getLineNumber());
67         }
68         return builder.toString();
69     }
70 }
71