简单Java类深入

①实现基本字段的转换：

class Emp {
private String ename;
private int empno;
private double sal;
private double comm;
private String job;
//set.get略
public Emp() {}
public Emp(String ename,int empno,double sal,double comm,String job) {
this.ename=ename;
this.empno=empno;
this.sal=sal;
this.comm=comm;
this.job=job;
}
public String getInfo(){
return ename+empno+sal+comm+job;
}
}
class Dept {
private int deptno;
private String dname;
//set.get略
public Dept(){}
public Dept(int deptno,String dname){
this.deptno=deptno;
this.dname=dname;
}
public String getInfo(){
return deptno+dname;
}
}
public class person {
public static void main (String args[]){

}
}

②解决外键关系

class Emp {
    private String ename;
    private int empno;
    private double sal;
    private double comm;
    private String job;    //set.get略
    private Dept dept;
    private Emp mgr;
    public void setDept(Dept dept){ 
       this.dept=dept;
       }
    public void setMgr(Emp mgr){
       this.mgr=mgr;
       }
     public Dept getDept(){
       return this.dept;
       }
     public Emp getMgr(){
       return this.mgr;
       }
    public Emp() {} 
    public Emp(String ename,int empno,double sal,double comm,String job) {
    this.ename=ename;
    this.empno=empno;
    this.sal=sal;
    this.comm=comm;
    this.job=job;
    } 
public String getInfo(){
   return ename+empno+sal+comm+job;//this.略
   }
}
class Dept {
    private int deptno;
    private String dname;//set.get略
    private Emp emps [] ;
    public void setEmps(Emp [] emps ){
       this.emps=emps;
       }
     public Emp [] getEmps(){
       return this.emps;
       }
    public Dept(){}
    public Dept(int deptno,String dname){
    this.deptno=deptno;
    this.dname=dname;
    }
public String getInfo(){
    return deptno+dname;//this略
    }
}
public class person {
    public static void main (String args[]){
   
   } 
}

③设置数据与取出数据 

class Emp {
    private String ename;
    private int empno;
    private double sal;
    private double comm;
    private String job;    //set.get略
    private Dept dept;
    private Emp mgr;
    public void setDept(Dept dept){ 
       this.dept=dept;
       }
    public void setMgr(Emp mgr){
       this.mgr=mgr;
       }
     public Dept getDept(){
       return this.dept;
       }
     public Emp getMgr(){
       return this.mgr;
       }
    public Emp() {} 
    public Emp(String ename,int empno,double sal,double comm,String job) {
    this.ename=ename;
    this.empno=empno;
    this.sal=sal;
    this.comm=comm;
    this.job=job;
    } 
public String getInfo(){
   return "姓名: "+ename+", 编号: "+empno+", 工资: "+sal+", 佣金: "+comm+", 职位: "+job;//this.略
   }
}
class Dept {
    private int deptno;
    private String dname;//set.get略
    private Emp emps [] ;
    public void setEmps(Emp [] emps ){
       this.emps=emps;
       }
     public Emp [] getEmps(){
       return this.emps;
       }
    public Dept(){}
    public Dept(int deptno,String dname){
    this.deptno=deptno;
    this.dname=dname;
    }
public String getInfo(){
    return "编号: "+deptno+", 客栈名称: "+dname;//this略
    }
}
public class person {
    public static void main (String args[]){
   Emp aa = new Emp("阿一",1,111.1,1.1,"炊事部");
   Emp bb = new Emp("小二",2,222.2,2.2,"伙计");
   Emp cc = new Emp("张三",3,333.3,3.3,"客栈老板");
   Dept dd = new Dept(4,"安居客栈");
   aa.setMgr(cc);
   bb.setMgr(cc);
   aa.setDept(dd);
   bb.setDept(dd);
   cc.setDept(dd);
   dd.setEmps(new Emp[] {aa,bb});

   System.out.println(aa.getInfo());
   System.out.println(aa.getMgr().getInfo());
   System.out.println(aa.getDept().getInfo());
  System.out.println("******************");
  System.out.println("******************");
   for (int x=0;x<dd.getEmps().length ;x++ ) {
       System.out.println(dd.getEmps()[x].getInfo() );
        System.out.println(dd.getEmps()[x].getMgr().getInfo() );  
   }
   } 
}