Java : Member with Examples

public class Foo {
    private int num;

    public Foo(double d) {
    }

    public void aaa(String str) {
    }
}

final var cls = Foo.class;

final Member constructor = cls.getDeclaredConstructor(double.class);
System.out.println(constructor); // public Foo(double)

final Member method = cls.getDeclaredMethod("aaa", String.class);
System.out.println(method); // public void Foo.aaa(java.lang.String)

final Member field = cls.getDeclaredField("num");
System.out.println(field); // private int Foo.num

static final int DECLARED

Identifies the set of declared members of a class or interface.

System.out.println(Member.DECLARED); // 1

static final int PUBLIC

Identifies the set of all public members of a class or interface, including inherited members.

System.out.println(Member.PUBLIC); // 0

Class<?> getDeclaringClass ()

Returns the Class object representing the class or interface that declares the member or constructor represented by this Member.

class Foo {
    private String str;
}

final Member member = Foo.class.getDeclaredField("str");
System.out.println(member); // private java.lang.String Foo.str
System.out.println(member.getDeclaringClass()); // class Foo

int getModifiers ()

Returns the Java language modifiers for the member or constructor represented by this Member, as an integer.

class Foo {
    public int a;
    protected int b;
    private int c;
}

final var cls = Foo.class;

for (final Member member : cls.getDeclaredFields()) {
    final var mod = member.getModifiers();
    System.out.println("name = " + member.getName() + " : mod = " + mod);
    System.out.println("  isPublic : " + Modifier.isPublic(mod));
    System.out.println("  isProtected : " + Modifier.isProtected(mod));
    System.out.println("  isPrivate : " + Modifier.isPrivate(mod));
}

// Result
// ↓
//name = a : mod = 1
//  isPublic : true
//  isProtected : false
//  isPrivate : false
//name = b : mod = 4
//  isPublic : false
//  isProtected : true
//  isPrivate : false
//name = c : mod = 2
//  isPublic : false
//  isProtected : false
//  isPrivate : true

String getName ()

Returns the simple name of the underlying member or constructor represented by this Member.

public class Foo {
    private int num;

    public Foo(double d) {
    }

    public void aaa(String str) {
    }
}

final var cls = Foo.class;

final Member constructor = cls.getDeclaredConstructor(double.class);
System.out.println(constructor); // public Foo(double)
System.out.println(constructor.getName()); // Foo

final Member method = cls.getDeclaredMethod("aaa", String.class);
System.out.println(method); // public void Foo.aaa(java.lang.String)
System.out.println(method.getName()); // aaa

final Member field = cls.getDeclaredField("num");
System.out.println(field); // private int Foo.num
System.out.println(field.getName()); // num

boolean isSynthetic ()

Returns true if this member was introduced by the compiler; returns false otherwise.

import java.lang.reflect.Member;

public class IsSyntheticTest {

    interface Foo<T> {
        void aaa(T value);
    }

    class Bar implements Foo<String> {
        @Override
        public void aaa(String value) {
        }
    }

    public static void main(String[] args) {

        final var cls = Bar.class;

        for (final Member member : cls.getDeclaredMethods()) {
            System.out.println(member);
            System.out.println(member.isSynthetic());
        }

        // Result
        // ↓
        //public void IsSyntheticTest$Bar.aaa(java.lang.String)
        //false
        //public void IsSyntheticTest$Bar.aaa(java.lang.Object)
        //true
    }
}