Java example source code file (StaticFieldTest.java)

This example Java source code file (StaticFieldTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

field, hello, nosuchfieldexception, reflection, runtimeexception, staticfieldtest, string, test

The StaticFieldTest.java Java example source code

/*
 * Copyright (c) 2001, 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.
 */

/*
  @test
  @bug 4490864
  @summary Verify reflective static field accesses (sanity check)
  @author Kenneth Russell
*/

import java.lang.reflect.*;

public class StaticFieldTest {
    private static byte   byteField;
    private static short  shortField;
    private static char   charField;
    private static int    intField;
    private static long   longField;
    private static float  floatField;
    private static double doubleField;
    private static String stringField;

    private static Field getAccessibleField(String name) throws NoSuchFieldException {
        Field f = StaticFieldTest.class.getDeclaredField(name);
        f.setAccessible(true);
        return f;
    }

    public static void main(String[] args) throws Exception {
        Field byteField   = getAccessibleField("byteField");
        Field shortField  = getAccessibleField("shortField");
        Field charField   = getAccessibleField("charField");
        Field intField    = getAccessibleField("intField");
        Field longField   = getAccessibleField("longField");
        Field floatField  = getAccessibleField("floatField");
        Field doubleField = getAccessibleField("doubleField");
        Field stringField = getAccessibleField("stringField");

        byteField.setByte    (null, (byte) 77);
        shortField.setShort  (null, (short) 77);
        charField.setChar    (null, (char) 77);
        intField.setInt      (null, (int) 77);
        longField.setLong    (null, (long) 77);
        floatField.setFloat  (null, (float) 77);
        doubleField.setDouble(null, (double) 77);
        String myString = "Hello, world";
        stringField.set      (null, myString);

        if (byteField.getByte(null)     != 77) throw new RuntimeException("Test failed");
        if (shortField.getShort(null)   != 77) throw new RuntimeException("Test failed");
        if (charField.getChar(null)     != 77) throw new RuntimeException("Test failed");
        if (intField.getInt(null)       != 77) throw new RuntimeException("Test failed");
        if (longField.getLong(null)     != 77) throw new RuntimeException("Test failed");
        if (floatField.getFloat(null)   != 77) throw new RuntimeException("Test failed");
        if (doubleField.getDouble(null) != 77) throw new RuntimeException("Test failed");
        if (stringField.get(null)       != myString) throw new RuntimeException("Test failed");

        // Test passed.
    }
}