Tue, 14 May 2013 11:11:09 -0700
8012556: Implement lambda methods on interfaces as static
8006140: Javac NPE compiling Lambda expression on initialization expression of static field in interface
Summary: Lambdas occurring in static contexts or those not needing instance information should be generated into static methods. This has long been the case for classes. However, as a work-around to the lack of support for statics on interfaces, interface lambda methods have been generated into default methods. For lambdas in interface static contexts (fields and static methods) this causes an NPE in javac because there is no 'this'. MethodHandles now support static methods on interfaces. This changeset allows lambda methods to be generated as static interface methods. An existing bug in Hotspot (8013875) is exposed in a test when the "-esa" flag is used. This test and another test that already exposed this bug have been marked with @ignore.
Reviewed-by: mcimadamore
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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24 */
26 /**
27 * @test
28 * @bug 8003639
29 * @summary convert lambda testng tests to jtreg and add them
30 * @run testng MethodReferenceTestInnerDefault
31 */
33 import org.testng.annotations.Test;
35 import static org.testng.Assert.assertEquals;
37 /**
38 * @author Robert Field
39 */
41 interface IDSs { String m(String a); }
43 interface InDefA {
44 default String xsA__(String s) {
45 return "A__xsA:" + s;
46 }
48 default String xsAB_(String s) {
49 return "AB_xsA:" + s;
50 }
52 }
54 interface InDefB extends InDefA {
56 default String xsAB_(String s) {
57 return "AB_xsB:" + s;
58 }
60 default String xs_B_(String s) {
61 return "_B_xsB:" + s;
62 }
63 }
65 @Test
66 public class MethodReferenceTestInnerDefault implements InDefB {
68 public void testMethodReferenceInnerDefault() {
69 (new In()).testMethodReferenceInnerDefault();
70 }
72 class In {
74 public void testMethodReferenceInnerDefault() {
75 IDSs q;
77 q = MethodReferenceTestInnerDefault.this::xsA__;
78 assertEquals(q.m("*"), "A__xsA:*");
80 q = MethodReferenceTestInnerDefault.this::xsAB_;
81 assertEquals(q.m("*"), "AB_xsB:*");
83 q = MethodReferenceTestInnerDefault.this::xs_B_;
84 assertEquals(q.m("*"), "_B_xsB:*");
85 }
86 }
88 }