Errors in Map class

Question

Hello Everyone.
Well I working on a program that uses Map class and I have some errors.
They are listed as.
on line 110
Type safety: The method put(Object, Object) belongs to the raw type HashMap. References to
generic type HashMap<K,V> should be parameterized
line 115
pe safety: The expression of type Collection needs unchecked conversion to conform to
Collection<ComputerInvent>
line 123
Type mismatch: cannot convert from Object to Computer_listing
Here is my code is far
import java.io.*;
import java.util.*;
class Computer_listing {
     private String id;
     private String name;
     private Integer harddrive;
     private Integer memory;
     private float speed;
     public Computer_listing(String idx) {
          id = idx;
     }// close the computer_listing loop
      * Constructors.
     public Computer_listing(String cd, String cn, Integer hd, Integer me,
               float sp) {
          id = cd;
          name = cn;
          harddrive = hd;
          memory = me;
          speed = sp;
     }// close public EmployeeClass
      * accessors make info available
     public String getId() {
          return id;
     public String getName() {
          return name;
     public Integer getHardrive() {
          return harddrive;
     public Integer getMemory() {
          return memory;
     public float getSpeed() {
          return speed;
      * Mutator Methods
     public void setId(String cd) {
          id = cd;
     public void setName(String cn) {
          name = cn;
     public void setHarddrive(Integer hd) {
          harddrive = hd;
     public void setMemory(Integer me) {
          memory = me;
     public void setSpeed(float sp) {
          speed = sp;
}// close class
public class ComputerInvent {
     public static void main(String[] args) {
          HashMap hs = new HashMap();
          Scanner kbd = new Scanner(System.in);
          kbd.useDelimiter("\n");
          while (true) {
               String msg = null;
               Computer_listing compdb = null;
               System.out.println("Enter ComputerID - Stop to end");
               msg = kbd.next();
               if (msg.equalsIgnoreCase("STOP")) {
                    break;
               } else {
                    compdb = new Computer_listing(msg);
               System.out.println("Enter Computer Name");
               compdb.setId(kbd.next());
               System.out.println("Enter HardDrive");
               compdb.setHarddrive(kbd.nextInt());
               System.out.println("Enter Memory");
               compdb.setMemory(kbd.nextInt());
               System.out.println("Enter Speed");
               compdb.setSpeed(kbd.nextFloat());
               // add to data structure
               hs.put(msg, hs); //line 110
          }// close while loop
          System.out.println("Done");
          int i = 1;
          Collection<ComputerInvent> values = hs.values();//line115
          for (ComputerInvent temp : values) {
               System.out.println("Items are " + i + "" + temp.getClass());
               i++;
          }// close for loop
          System.out.println("Enter ID to find");
          String findit = kbd.next();
          Computer_listing x = null;
          if ((x = hs.get(findit)) != null) { //line 123
               System.out.println("Found it");
               System.out.println("Name is " + x.getClass());
          } else {
               System.out.println("Did not find it");
          }// close else
     }// close public static void
}// close public class ComputerInventCan someone please help me in solving this.
thanks
sandyR

Answer 1

The code should have thrown hundreds of errors i wonder how u managed with few
import java.io.*;
import java.util.*;
class Computer_listing {
     private String id;
     private String name;
     private Integer harddrive;
     private Integer memory;
     private float speed;
     public Computer_listing(String idx) {
              this.id = idx;
     public Computer_listing(String cd, String cn, Integer hd, Integer me,
               float sp) {
          this.id = cd;
          this.name = cn;
          this.harddrive = hd;
          this.memory = me;
          this.speed = sp;
     public String getId() {
          return this.id;
     public String getName() {
          return this.name;
     public Integer getHardrive() {
          return this.harddrive;
     public Integer getMemory() {
          return this.memory;
     public float getSpeed() {
          return this.speed;
     public void setId(String cd) {
          this.id = cd;
     public void setName(String cn) {
             this.name = cn;
     public void setHarddrive(Integer hd) {
          this.harddrive = hd;
     public void setMemory(Integer me) {
          this.memory = me;
     public void setSpeed(float sp) {
          this.speed = sp;
public class ComputerInvent{
  public static void main(String s[]){
         HashMap<String,Computer_listing> hs = new HashMap<String,Computer_listing>();
         Scanner kbd = new Scanner(System.in);
         kbd.useDelimiter("\n");
           while(true){ 
               String msg = null;
               Computer_listing compdb = null;
                System.out.println("Enter <ComputerID> - Type <Stop> to end");
                msg = kbd.next();
                if (msg.equalsIgnoreCase("STOP"))
            break;
                 else
            compdb = new Computer_listing(msg);
                System.out.println("Enter Computer Name:");
          compdb.setId(kbd.next());
          System.out.println("Enter HardDrive:");
          compdb.setHarddrive(kbd.nextInt());
          System.out.println("Enter Memory:");
          compdb.setMemory(kbd.nextInt());
          System.out.println("Enter Clock Speed:");
          compdb.setSpeed(kbd.nextFloat());                
                hs.put(msg,compdb);
          System.out.println("<Done>");
          Collection<Computer_listing> values = hs.values();
          int i = 0;
          for (Computer_listing temp : values) {
               System.out.println("Name["+ i + "]:" + temp.getName());
               i++;
          System.out.println("Enter ID to find");
       String findit = kbd.next();
          Computer_listing x = null;
             if ((x = hs.get(findit)) != null) {
               System.out.println("Found it");
               System.out.println("Name is " + x.getName());
          } else {
               System.out.println("Did not find it");
}Hope that works :)
Anyways i'd advice you learn basics of using java.util Classes first and then go about using generics if you are a starter.
REGARDS,
RaHuL