1 /*
2  * Copyright (C) 2018 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 import java.lang.invoke.MethodHandles;
18 import java.lang.invoke.MethodType;
19 
20 /** Class with helper methods for field and method lookups using java.lang.invoke. */
21 public class JLI {
canDiscoverWithLookupFindGetter( MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType)22   public static boolean canDiscoverWithLookupFindGetter(
23       MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType) {
24     try {
25       return lookup.findGetter(klass, fieldName, fieldType) != null;
26     } catch (NoSuchFieldException e) {
27       return false;
28     } catch (IllegalAccessException e) {
29       return true;
30     }
31   }
32 
canDiscoverWithLookupFindSetter( MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType)33   public static boolean canDiscoverWithLookupFindSetter(
34       MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType) {
35     try {
36       return lookup.findSetter(klass, fieldName, fieldType) != null;
37     } catch (NoSuchFieldException e) {
38       return false;
39     } catch (IllegalAccessException e) {
40       return true;
41     }
42   }
43 
canDiscoverWithLookupFindStaticGetter( MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType)44   public static boolean canDiscoverWithLookupFindStaticGetter(
45       MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType) {
46     try {
47       return lookup.findStaticGetter(klass, fieldName, fieldType) != null;
48     } catch (NoSuchFieldException e) {
49       return false;
50     } catch (IllegalAccessException e) {
51       return true;
52     }
53   }
54 
canDiscoverWithLookupFindStaticSetter( MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType)55   public static boolean canDiscoverWithLookupFindStaticSetter(
56       MethodHandles.Lookup lookup, Class<?> klass, String fieldName, Class<?> fieldType) {
57     try {
58       return lookup.findStaticSetter(klass, fieldName, fieldType) != null;
59     } catch (NoSuchFieldException e) {
60       return false;
61     } catch (IllegalAccessException e) {
62       return true;
63     }
64   }
65 
canDiscoverWithLookupFindConstructor( MethodHandles.Lookup lookup, Class<?> klass, MethodType methodType)66   public static boolean canDiscoverWithLookupFindConstructor(
67       MethodHandles.Lookup lookup, Class<?> klass, MethodType methodType) {
68     try {
69       return lookup.findConstructor(klass, methodType) != null;
70     } catch (NoSuchMethodException e) {
71       return false;
72     } catch (IllegalAccessException e) {
73       return true;
74     }
75   }
76 
canDiscoverWithLookupFindVirtual( MethodHandles.Lookup lookup, Class<?> klass, String methodName, MethodType methodType)77   public static boolean canDiscoverWithLookupFindVirtual(
78       MethodHandles.Lookup lookup, Class<?> klass, String methodName, MethodType methodType) {
79     try {
80       return lookup.findVirtual(klass, methodName, methodType) != null;
81     } catch (NoSuchMethodException e) {
82       return false;
83     } catch (IllegalAccessException e) {
84       return true;
85     }
86   }
87 
canDiscoverWithLookupFindStatic( MethodHandles.Lookup lookup, Class<?> klass, String methodName, MethodType methodType)88   public static boolean canDiscoverWithLookupFindStatic(
89       MethodHandles.Lookup lookup, Class<?> klass, String methodName, MethodType methodType) {
90     try {
91       return lookup.findStatic(klass, methodName, methodType) != null;
92     } catch (NoSuchMethodException e) {
93       return false;
94     } catch (IllegalAccessException e) {
95       return true;
96     }
97   }
98 }
99