package test06;
public class PermissionModel {
private int age;
public String name;
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
package test06;
public class PermissionTest {
public static void main(String[] args) {
PermissionModel p=new PermissionModel();
p.getAge();
p.setAge(12);
p.getName();
p.setName("wang");
p.name="wangsong";//public 方法可以在类外部访问
p.age=12;//这个方法是错误的，私有方法，只能在类内部访问
}
//public 可以直接访问这个类内部的元素
public void setName(){
new PermissionModel().name="li";
}
}访问权限的控制加强了具体实现的隐藏
定制自己的工具库取代输出package test06.util;
import java.util.Locale;
public class Print {
public static void print(boolean b){
System.out.print(b);
}
public static void print(char c){
System.out.print(c);
}
public static void print(char []s){
System.out.print(s);
}
public static void print(double d){
System.out.print(d);
}
public static void print(float f){
System.out.print(f);
}
public static void print(int i){
System.out.print(i);
}
public static void print(long l){
System.out.print(l);
}
public static void print(String s){
System.out.print(s);
}
public static void printf(Locale l,String format,Object args){
System.out.printf(l, format, args);
}
public static void println(){
System.out.println();
}
public static void println(boolean b){
System.out.println(b);
}
public static void println(char c){
System.out.println(c);
}
public static void println(char []s){
System.out.println(s);
}
public static void println(double d){
System.out.println(d);
}
public static void println(float f){
System.out.println(f);
}
public static void println(int i){
System.out.println(i);
}
public static void println(long l){
System.out.println(l);
}
public static void println(Object obj){
System.out.println(obj);
}
public static void println(String s){
System.out.println(s);
}
}用static引入包
package test06;
import static test06.util.Print.*;
public class Hello {
public static void main(String[] args) {
print("Hello World!");
}
}