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/*
* Copyright (c) 2023, 2024, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* 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).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;
import java.util.Objects;
import java.util.function.Consumer;
/**
* @test
* @bug 8329420
* @summary test execution priority and behavior of main methods
* @run main InstanceMainTest
*/
public class InstanceMainTest extends TestHelper {
private static final String[] SOURCES = new String[] {
// static dominating with args
"""
class MainClass {
static void main() {
throw new AssertionError();
}
static void main(String[] args) {
}
}
""",
// instance dominating static
"""
class MainClass {
void main(String[] args) {
}
static void main() {
throw new AssertionError();
}
}
""",
// instance dominating with args
"""
class MainClass {
void main() {
throw new AssertionError();
}
void main(String[] args) {
}
}
""",
// instance no args
"""
class MainClass {
void main() {
}
}
""",
// unnamed class static dominating with args
"""
static void main() {
throw new AssertionError();
}
static void main(String[] args) {
}
""",
// main with args dominating main without args
"""
void main(String[] args) {
}
static void main() {
throw new AssertionError();
}
""",
// unnamed class instance dominating with args
"""
void main() {
throw new AssertionError();
}
void main(String[] args) {
}
""",
// unnamed class instance main no args
"""
void main() {
}
""",
// instance main with args dominating super
"""
class MainClass extends SuperClass {
void main() {
throw new AssertionError();
}
}
class SuperClass {
void main(String[] args) {
}
}
""",
// super instance main with args dominating
"""
public class MainClass extends Super {
}
class Super {
public void main(String... args) {
}
public void main() {
throw new AssertionError();
}
}
""",
// ignore super instance main
"""
public class MainClass extends Super {
public static void main(String... args) {
}
}
class Super {
public static void main(String... args) {
throw new AssertionError();
}
}
""",
// enum main
"""
enum MainClass {
A;
public static void main() {
}
}
""",
// record main
"""
record MainClass() {
static void main() {
System.out.println("Done!");
}
}
""",
// interface main
"""
interface MainClass {
static void main() {
System.out.println("Done!");
}
}
"""
};
private static void testMethodOrder() throws Exception {
for (String source : SOURCES) {
performTest(source, true, tr -> {
if (!tr.isOK()) {
System.err.println(source);
System.err.println(tr);
throw new AssertionError();
}
});
}
}
record TestCase(String sourceCode, boolean enablePreview, List<String> expectedOutput) {
public TestCase(String sourceCode, List<String> expectedOutput) {
this(sourceCode, true, expectedOutput);
}
}
private static final TestCase[] EXECUTION_ORDER = new TestCase[] {
new TestCase("""
public class MainClass {
public MainClass() {
System.out.println("Constructor called!");
}
public static void main() {
System.out.println("main called!");
}
}
""",
List.of("main called!")),
new TestCase("""
public class MainClass {
public MainClass() {
System.out.println("Constructor called!");
}
public void main() {
System.out.println("main called!");
}
}
""",
List.of("Constructor called!", "main called!"))
};
private static void testExecutionOrder() throws Exception {
for (TestCase testCase : EXECUTION_ORDER) {
performTest(testCase.sourceCode, testCase.enablePreview(), tr -> {
if (!Objects.equals(testCase.expectedOutput, tr.testOutput)) {
throw new AssertionError("Unexpected output, " +
"expected: " + testCase.expectedOutput +
", actual: " + tr.testOutput);
}
});
}
}
private static final TestCase[] EXECUTION_ERRORS = new TestCase[] {
new TestCase("""
public class MainClass {
public MainClass() {
System.out.println("Constructor called!");
if (true) throw new Error();
}
public void main(String... args) {
System.out.println("main called!");
}
}
""",
List.of("Constructor called!",
"Exception in thread \"main\" java.lang.Error",
"\tat MainClass.<init>(MainClass.java:4)")),
new TestCase("""
public class MainClass {
public MainClass() {
System.out.println("Constructor called!");
if (true) throw new Error();
}
public void main() {
System.out.println("main called!");
}
}
""",
List.of("Constructor called!",
"Exception in thread \"main\" java.lang.Error",
"\tat MainClass.<init>(MainClass.java:4)")),
new TestCase("""
public class MainClass {
static int idx;
public MainClass() {
System.out.println("Constructor called!");
if (idx++ == 0) throw new Error();
}
public void main(String... args) {
System.out.println("main called!");
}
public void main() {
System.out.println("main called!");
}
}
""",
List.of("Constructor called!",
"Exception in thread \"main\" java.lang.Error",
"\tat MainClass.<init>(MainClass.java:5)")),
new TestCase("""
public class MainClass {
static {
System.out.println("static init called!");
if (true) throw new Error();
}
public static void main(String... args) {
System.out.println("main called!");
}
}
""",
false,
List.of("static init called!",
"Exception in thread \"main\" java.lang.Error",
"\tat MainClass.<clinit>(MainClass.java:4)")),
new TestCase("""
public class MainClass {
static {
System.out.println("static init called!");
if (true) throw new Error();
}
public static void main(String... args) {
System.out.println("main called!");
}
}
""",
true,
List.of("static init called!",
"Exception in thread \"main\" java.lang.Error",
"\tat MainClass.<clinit>(MainClass.java:4)")),
new TestCase("""
public class MainClass {
static {
System.out.println("static init called!");
if (true) throw new Error();
}
public void main(String... args) {
System.out.println("main called!");
}
}
""",
true,
List.of("static init called!",
"Exception in thread \"main\" java.lang.Error",
"\tat MainClass.<clinit>(MainClass.java:4)")),
};
private static void testExecutionErrors() throws Exception {
for (TestCase testCase : EXECUTION_ERRORS) {
performTest(testCase.sourceCode, testCase.enablePreview(), tr -> {
for (int i = 0; i < testCase.expectedOutput.size(); i++) {
if (i >= tr.testOutput.size() ||
!Objects.equals(testCase.expectedOutput.get(i),
tr.testOutput.get(i))) {
throw new AssertionError("Unexpected output, " +
"expected: " + testCase.expectedOutput +
", actual: " + tr.testOutput +
", failed comparison at index: " + i);
}
}
});
}
}
private static void performTest(String source, boolean enablePreview, Consumer<TestResult> validator) throws Exception {
Path mainClass = Path.of("MainClass.java");
Files.writeString(mainClass, source);
var version = System.getProperty("java.specification.version");
var previewRuntime = enablePreview ? "--enable-preview" : "-DtestNoPreview";
var previewCompile = enablePreview ? "--enable-preview" : "-XDtestNoPreview";
var trSource = doExec(javaCmd, previewRuntime, "--source", version, "MainClass.java");
validator.accept(trSource);
compile(previewCompile, "--source", version, "MainClass.java");
String cp = mainClass.toAbsolutePath().getParent().toString();
var trCompile = doExec(javaCmd, previewRuntime, "--class-path", cp, "MainClass");
validator.accept(trCompile);
}
public static void main(String... args) throws Exception {
testMethodOrder();
testExecutionOrder();
testExecutionErrors();
}
}
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