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*
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
/**
* @test
* @bug 8003280
* @summary Add lambda tests
* Test SAM conversion of method references in contexts of assignment, method/constructor argument,
* return statement, array initializer, lambda expression body, conditional expression and cast.
* @compile SamConversion.java
* @run main SamConversion
*/
public class SamConversion {
static int assertionCount = 0;
static interface Foo {
Integer m(int i);
}
static interface Bar {
int m(Integer i) throws MyException;
}
private static void assertTrue(boolean b) {
assertionCount++;
if(!b)
throw new AssertionError();
}
private static int test1(Foo foo) {
return foo.m(1);
}
private static void test2(Bar bar, int result) {
try {
assertTrue(bar.m(1) == result);
} catch (Exception e){
assertTrue(false);
}
}
private static Bar test3(int i) {
switch (i) {
case 0:
return A::method1;
case 1:
return new A()::method2;
case 2:
return A::method3;
case 3:
return new A()::method4;
case 4:
return new A()::method5;
case 5:
return A::method6;
default:
return null;
}
}
/**
* Test SAM conversion of method reference in assignment context
*/
private static void testAssignment() {
Foo foo = A::method1; //static reference, parameter type matching and return type matching
assertTrue(foo.m(1) == 2);
foo = new A()::method2; //instance reference, parameter type unboxing and return type boxing
assertTrue(foo.m(1) == 3);
foo = A::method3; //static reference, parameter type matching and return type boxing
assertTrue(foo.m(1) == 4);
foo = new A()::method4; //instance reference, parameter type unboxing and return type matching
assertTrue(foo.m(1) == 5);
foo = new A()::method5; //instance reference, parameter type unboxing and return type matching
assertTrue(foo.m(1) == 6);
Bar bar = A::method1;
try {
assertTrue(bar.m(1) == 2);
} catch (Exception e) {
assertTrue(false);
}
bar = new A()::method2;
try {
assertTrue(bar.m(1) == 3);
} catch (Exception e) {
assertTrue(false);
}
bar = A::method3;
try {
assertTrue(bar.m(1) == 4);
} catch (Exception e) {
assertTrue(false);
}
bar = new A()::method4;
try {
assertTrue(bar.m(1) == 5);
} catch (Exception e) {
assertTrue(false);
}
bar = new A()::method5;
try {
assertTrue(bar.m(1) == 6);
} catch (Exception e) {
assertTrue(false);
}
}
/**
* Test SAM conversion of method reference in method/constructor argument context
*/
private static void testMethodArgument() {
assertTrue(test1(A::method1) == 2);
assertTrue(test1(new A()::method2) == 3);
assertTrue(test1(A::method3) == 4);
assertTrue(test1(new A()::method4) == 5);
assertTrue(test1(new A()::method5) == 6);
test2(A::method1, 2);
test2(new A()::method2, 3);
test2(A::method3, 4);
test2(new A()::method4, 5);
test2(new A()::method5, 6);
}
/**
* Test SAM conversion of method reference in return statement context
*/
private static void testReturnStatement() {
Bar bar = test3(0);
try {
assertTrue(bar.m(1) == 2);
} catch (Exception e) {
assertTrue(false);
}
bar = test3(1);
try {
assertTrue(bar.m(1) == 3);
} catch (Exception e) {
assertTrue(false);
}
bar = test3(2);
try {
assertTrue(bar.m(1) == 4);
} catch (Exception e) {
assertTrue(false);
}
bar = test3(3);
try {
assertTrue(bar.m(1) == 5);
} catch (Exception e) {
assertTrue(false);
}
bar = test3(4);
try {
assertTrue(bar.m(1) == 6);
} catch (Exception e) {
assertTrue(false);
}
bar = test3(5);
try {
bar.m(1);
assertTrue(false);
} catch (MyException e) {
} catch (Exception e) {
assertTrue(false);
}
}
/**
* Test SAM conversion of method reference in cast context
*/
private static void testCast() {
assertTrue(((Foo)A::method1).m(1) == 2);
try {
assertTrue(((Bar)new A()::method2).m(1) == 3);
} catch (Exception e) {
assertTrue(false);
}
}
/**
* Test SAM conversion of method reference in array initializer context
*/
private static void testArrayInitializer() {
Object[] oarray = {"a", 1, (Foo)A::method3}; //last element need a cast
Object[] oarray2 = {"a", 1, (Bar)new A()::method4}; //last element need a cast
Foo[] farray = {A::method1, new A()::method2, A::method3, new A()::method4, new A()::method5};
Bar[] barray = {A::method1, new A()::method2, A::method3, new A()::method4, new A()::method5, A::method6};
}
/**
* Test SAM conversion of method reference in conditional expression context
*/
private static void testConditionalExpression(boolean b) {
Foo f = b ? A::method3 : new A()::method5;
if(b)
assertTrue(f.m(1) == 4);
else
assertTrue(f.m(1) == 6);
Bar bar = b ? A::method1 : A::method6;
if(b) {
try {
assertTrue(bar.m(1) == 2);
} catch (Exception e) {
assertTrue(false);
}
}
else {
try {
bar.m(1);
assertTrue(false);
} catch (MyException e) {
} catch (Exception e) {
assertTrue(false);
}
}
}
/**
* Test SAM conversion of method reference in lambda expression body
*/
private static void testLambdaExpressionBody() {
Foo f = n -> ((Foo)A::method3).m(n);
assertTrue(f.m(1) == 4);
Bar b = n -> { return ((Foo)new A()::method5).m(n); };
try {
assertTrue(b.m(1) == 6);
} catch (Exception e) {
assertTrue(false);
}
}
public static void main(String[] args) {
testAssignment();
testMethodArgument();
testReturnStatement();
testCast();
testArrayInitializer();
testConditionalExpression(true);
testConditionalExpression(false);
testLambdaExpressionBody();
assertTrue(assertionCount == 32);
}
static class MyException extends Exception {}
static class A {
int value = 0;
A() {
}
A(Foo f) {
value = f.m(9);
}
A(Bar b) {
try {
value = b.m(9);
} catch (MyException e){}
}
static Integer method1(int n) {
return n + 1;
}
int method2(Integer n) {
return value == 0 ? n + 2 : n + value;
}
static int method3(int n) {
return n + 3;
}
Integer method4(Integer n) {
return value == 0 ? n + 4 : n + value;
}
Integer method5(Integer n) {
return value == 0 ? new Integer(n + 5) : new Integer(n + value);
}
static int method6(Integer n) throws MyException{
throw new MyException();
}
}
}