How to avoid using dynamic variables / billions if instructions in Java?

Question

So, since dynamic variables are nothing in Java, and if the instructions are terribly cumbersome, they looked for help, turning this block of code into a more concise one.

I looked at the hashmaps and they just didn't seem completely correct, but I probably didn't understand them.

public String m1 = "Name1";
public String m1ip = "192.1.1.1";
public String m2 = "Name2";
public String m2ip = "192.1.1.1";
public String req;
public String reqip;

... edit the code ...

if (requestedMachine == 1)
{ req = m1; reqip = m1ip;}
else if (requestedMachine == 2)
{ req = m2; reqip = m2ip;}
else if (requestedMachine == 3)
{ req = m3; reqip = m3ip;}
else if (requestedMachine == 4)
{ req = m4; reqip = m4ip;}
else if (requestedMachine == 5)
{ req = m5; reqip = m5ip;}

requestMachine will be an integer that determines what values ​​req and reqip should be assigned.

Thanks in advance.

Answer 1

Define the Machine class containing the nameand field ip. Create an array of the machine. Enter the machine located at the index requestedMachine(or requestedMachine - 1, if the number starts with 1):

Machine[] machines = new Machine[] {
    new Machine("Name1", "192.1.1.1"),
    new Machine("Name2", "192.1.1.1"),
    ...
}
...

Machine machine = machines[requestedMachine - 1];

Answer 2

Machine:

class Machine {
    String name;
    String ip;
    //Constructor, getters, setters etc omitted
}

:

Machine[] machines = ... //initialize them with values

, requestedMachine:

Machine myMachine = machines[requestedMachine];

Answer 3

:

/**
   <P>{@code java EnumDeltaXmpl}</P>
 **/
public class EnumDeltaXmpl  {
  public static final void main(String[] ingo_red)  {
     test(MachineAction.ONE);
     test(MachineAction.TWO);
     test(MachineAction.THREE);
     test(MachineAction.FOUR);
  }
  private static final void test(MachineAction m_a)  {
     System.out.println("MachineAction." + m_a + ": name=" + m_a.sName + ", ip=" + m_a.sIP + "");
  }
}

enum MachineAction  {
   ONE("Name1", "192.1.1.1"),
   TWO("Name2", "292.2.2.2"),
   THREE("Name3", "392.3.3.3"),
   FOUR("Name4", "492.4.4.4"),
   FIVE("Name5", "592.5.5.5");

   public final String sName;
   public final String sIP;

   private MachineAction(String s_name, String s_ip)  {
      sName = s_name;
      sIP = s_ip;
   }
}

:

[C:\java_code\]java EnumDeltaXmpl
MachineAction.ONE: name=Name1, ip=192.1.1.1
MachineAction.TWO: name=Name2, ip=292.2.2.2
MachineAction.THREE: name=Name3, ip=392.3.3.3
MachineAction.FOUR: name=Name4, ip=492.4.4.4

Answer 4

- IP, .., .

public class Machine(){
private String name, ip;
public Machine(String name, String ip){
   this.name=name;
   // You can check a valid ip
   this.ip=ip;
}}


public class Machines(){
private Machine[] machines;
private int number_of_machines;
public Machines(){
  //define number_of_machines for your array and length of itself
}}
main()
Machine[] Machines = new Machine[number_of_machines];
Machine m1 = new Machine(String name, String ip);
.
.
.
Machine mn = new Machine(String name, String ip);
int number=5;
for(int i=0; i<number_of_machines; i++){
   if (machines[number]<number_of_machines){
      System.out.println("There is no machine with that number");
   }else if (machines[number]==number_of_machines-1){
      System.out.println("That is the choosen machine");
   }
}

}

Answer 5

id 0 , HashMap. -

HashMap<Integer, Machine> machines = new HashMap<>();
machines.put(1, machine1);
machines.put(7, machine7);
...

Machine machine7 = machines.get(7); 

, , . id 0,1,2,3,4,5,... , .