Get Access modifier from Field via reflection - Java Reflection

Java examples for Reflection:Field Get

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Description

Get Access modifier from Field via reflection

Demo Code

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import static java.lang.System.out;

enum Spy {/*from w  ww  . ja  v  a2s  .  c  o m*/
    BLACK, WHITE
}

public class FieldModifierSpy {
    volatile int share;
    int instance;

    class Inner {
    }

    public static void main(String... args) {
        try {
            Class<?> c = Class.forName(args[0]);
            int searchMods = 0x0;
            for (int i = 1; i < args.length; i++) {
                searchMods |= modifierFromString(args[i]);
            }

            Field[] flds = c.getDeclaredFields();
            out.format("Fields in Class '%s' containing modifiers:  %s%n",
                    c.getName(), Modifier.toString(searchMods));
            boolean found = false;
            for (Field f : flds) {
                int foundMods = f.getModifiers();
                // Require all of the requested modifiers to be present
                if ((foundMods & searchMods) == searchMods) {
                    out.format(
                            "%-8s [ synthetic=%-5b enum_constant=%-5b ]%n",
                            f.getName(), f.isSynthetic(),
                            f.isEnumConstant());
                    found = true;
                }
            }

            if (!found) {
                out.format("No matching fields%n");
            }

            // production code should handle this exception more gracefully
        } catch (ClassNotFoundException x) {
            x.printStackTrace();
        }
    }

    private static int modifierFromString(String s) {
        int m = 0x0;
        if ("public".equals(s))
            m |= Modifier.PUBLIC;
        else if ("protected".equals(s))
            m |= Modifier.PROTECTED;
        else if ("private".equals(s))
            m |= Modifier.PRIVATE;
        else if ("static".equals(s))
            m |= Modifier.STATIC;
        else if ("final".equals(s))
            m |= Modifier.FINAL;
        else if ("transient".equals(s))
            m |= Modifier.TRANSIENT;
        else if ("volatile".equals(s))
            m |= Modifier.VOLATILE;
        return m;
    }
}

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 *
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 *
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 *     from this software without specific prior written permission.
 *
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