以下是我打印未分类键值对的代码 .
我有2个POJO类和一个main方法 . 我必须根据 key 对我的hashmap进行排序 . 我需要在hashmap中执行此操作，而不能在treemap或其他任何内容中执行此操作 . 任何人都可以帮忙吗？
MAIN CLASS
public class HashDemo {public static void main（String args []）{
EmployeeBean e1=new EmployeeBean(100,"selva",1000);
EmployeeBean e2=new EmployeeBean(101,"siva",2000);
EmployeeBean e3=new EmployeeBean(102,"silva",3000);
DepartmentBean d1=new DepartmentBean(123);
DepartmentBean d2=new DepartmentBean(456);
DepartmentBean d3=new DepartmentBean(789);
Map <DepartmentBean,EmployeeBean> map=new HashMap<DepartmentBean,EmployeeBean>();
map.put(d1,e1);
map.put(d2,e2);
map.put(d3,e3);
for(Map.Entry m:map.entrySet()){
System.out.println(m.getKey()+" "+m.getValue());
}
}}
EMPLOYEEBEAN
公共类EmployeeBean {
private int empid;
private String empName;
private int empSal;
public int getEmpid() {
return empid;
}
public void setEmpid(int empid) {
this.empid = empid;
}
public String getEmpName() {
return empName;
}
public void setEmpName(String empName) {
this.empName = empName;
}
public int getEmpSal() {
return empSal;
}
public void setEmpSal(int empSal) {
this.empSal = empSal;
}
public EmployeeBean(int empid, String empName, int empSal) {
super();
this.empid = empid;
this.empName = empName;
this.empSal = empSal;
}
@Override
public String toString() {
return "empid=" + empid + ", empName=" + empName + ", empSal=" + empSal + "";
}
}
DEPARTMENTBEAN
public class DepartmentBean {private int deptId;
public int getDeptId() {
return deptId;
}
public void setDeptId(int deptId) {
this.deptId = deptId;
}
public DepartmentBean(int deptId) {
super();
this.deptId = deptId;
}
@Override
public String toString() {
return "deptId=" + deptId + "";
}
}