a.java

Java 入门书的源码

//Copyright (c) 1998, Arthur Gittleman
//This example is provided WITHOUT ANY WARRANTY either expressed or implied.

/* Public class A declares data fields and methods
 * with each of the four access modifiers
 * (including none) to illustrate their use.
 * Class B, not public, will be visible only in the
 * package visibility in which it is declared.
 */

package visibility;
public class A {
  public int d1=1;
  int d2=2;
  protected int d3=3;
  private int d4=4;

  public int get1() {
    return d1;
  }
  int get2() {
    return d2;
  }
  protected int get3() {
    return d3;
  }
  private int get4() {
    return d4;
  }
  public int usePrivate(){
    return d4 + get4();
  }
}
class B {
  public int d5=5;
}