Access modifiers from Constructor using reflection - Java Reflection

Java examples for Reflection:Constructor

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Description

Access modifiers from Constructor using reflection

Demo Code

import java.lang.reflect.Constructor;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import static java.lang.System.out;

public class ConstructorAccess {
    public static void main(String... args) {
        try {//  www  .  j a va 2 s  .c om
            Class<?> c = Class.forName(args[0]);
            Constructor[] allConstructors = c.getDeclaredConstructors();
            for (Constructor ctor : allConstructors) {
                int searchMod = modifierFromString(args[1]);
                int mods = accessModifiers(ctor.getModifiers());
                if (searchMod == mods) {
                    out.format("%s%n", ctor.toGenericString());
                    out.format("  [ synthetic=%-5b var_args=%-5b ]%n",
                            ctor.isSynthetic(), ctor.isVarArgs());
                }
            }

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

    private static int accessModifiers(int m) {
        return m
                & (Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED);
    }

    private static int modifierFromString(String s) {
        if ("public".equals(s))
            return Modifier.PUBLIC;
        else if ("protected".equals(s))
            return Modifier.PROTECTED;
        else if ("private".equals(s))
            return Modifier.PRIVATE;
        else if ("package-private".equals(s))
            return 0;
        else
            return -1;
    }
}

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