test/jdk/java/lang/Class/NameTest.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 2 along with this work; if not, write to the Free Software Foundation,
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/*
 * @test
 * @bug 8281671
 * @summary Checks on various "getFooName" methods of java.lang.Class
 */

import java.util.HashMap;
import java.util.Map;
import java.util.Objects;

public class NameTest {
    public static void main(String... args) {
        testCanonicalName();
        testSimpleName();
    }

    private static void testCanonicalName() {
        class LocalClass {} // Local class; no canonical name
        Object o = new Object() {}; // Anonymous class; no canonical name
        Object[] objectArray = {};

        Map<Class<?>, String> expectedCanonicalName = new HashMap<>();

        expectedCanonicalName.put(LocalClass.class,             null);
        expectedCanonicalName.put(o.getClass(),                 null);

        // If a component type doesn't have a canonical name, neither
        // does an array of that type.
        expectedCanonicalName.put(LocalClass.class.arrayType(), null);
        expectedCanonicalName.put(o.getClass().arrayType(),     null);

        expectedCanonicalName.put(int.class,              "int");
        expectedCanonicalName.put(Object.class,           "java.lang.Object");
        expectedCanonicalName.put(objectArray.getClass(), "java.lang.Object[]");

        for (var entry : expectedCanonicalName.entrySet()) {
            var key = entry.getKey();
            var expectedName = entry.getValue();
            String canonicalName = key.getCanonicalName();
            if (!Objects.equals(canonicalName, expectedName)) {
                System.err.println("Unexpected canonical name '" +
                                   canonicalName + "' found for " +
                                   key + ", expected " + expectedName);
                throw new RuntimeException();
            }
        }
    }

    private static void testSimpleName() {
        class ALocalClass {} // Local class
        Object o = new Object() {}; // Anonymous class, empty simple name
        Object[] objectArray = {};

        Map<Class<?>, String> expectedSimpleName = new HashMap<>();

        expectedSimpleName.put(ALocalClass.class,             "ALocalClass");
        expectedSimpleName.put(o.getClass(),                  "");

        expectedSimpleName.put(ALocalClass.class.arrayType(), "ALocalClass[]");
        expectedSimpleName.put(o.getClass().arrayType(),      "[]");

        expectedSimpleName.put(int.class,                     "int");
        expectedSimpleName.put(Object.class,                  "Object");
        expectedSimpleName.put(objectArray.getClass(),        "Object[]");

        for (var entry : expectedSimpleName.entrySet()) {
            var key = entry.getKey();
            var expectedName = entry.getValue();
            String simpleName = key.getSimpleName();
            if (!Objects.equals(simpleName, expectedName)) {
                System.err.println("Unexpected simple name '" +
                                   simpleName + "' found for " +
                                   key + ", expected " + expectedName);
                throw new RuntimeException();
            }
        }
    }
}