I am trying to insert the values to hash map through object, and i want to check if the values are inserted in to hash map. so i am using this code but in runtime i am not able to get any output.
How to resolve this?
Code:
import java.util.*;
import java.io.*;
import java.lang.*;
public class TaskList
{
private static HashMap<Integer, Object[]> dataz = new HashMap<Integer,Object[]>();
private static HashMap<Integer, Object[]> screen_dataz = new HashMap<Integer,Object[]>();
public final static Object[][] longValues = {{"10", "kstc-proc", "10.10.10.10.10.","5","O"},{"11", "proc-lvk1", "12.1.2.","4","O"},{"13", "trng-lvk1", "4.6.1.","3","O"}};
private static String sl,pid,tid,mval,status;
public static void main(String args[])
{
addTask();
}
public static void addTask()
{
for (int k=0; k<longValues.length; k++)
{
screen_dataz.put(k,longValues);
}
Set mapSet = (Set) screen_dataz.entrySet();
Iterator mapIterator = mapSet.iterator();
while (mapIterator.hasNext())
{
Map.Entry mapEntry = (Map.Entry) mapIterator.next();
String keyValue = (String) mapEntry.getKey();
String value = (String) mapEntry.getValue();
System.out.println(value);
}
}
}
First, you must add a row of the longValues
matrix to the map, and not the whole matrix:
for (int k=0; k<longValues.length; k++)
{
screen_dataz.put(k,longValues[k]);
}
Then, while iterating extract the value as Object[]
and not String
, and key as Integer
while (mapIterator.hasNext())
{
Map.Entry mapEntry = (Map.Entry) mapIterator.next();
Integer keyValue = (Integer) mapEntry.getKey();
Object[] value = (Object[]) mapEntry.getValue();
//iterate over the array and print each value
for (int i=0; i<value.length; i++) {
System.out.print(value[i] + " ");
}
System.out.println();
}
Your code with a few fixes/improvements:
screen_dataz
was always adding the same object the value stored in the map is an array which means it will not be printed as you expect with a simple call to toString()
public class TaskList { private static HashMap<Integer, String[]> dataz = new HashMap<Integer, String[]>(); private static HashMap<Integer, String[]> screen_dataz = new HashMap<Integer, String[]>(); public final static String[][] longValues = { { "10", "kstc-proc", "10.10.10.10.10.", "5", "O" }, { "11", "proc-lvk1", "12.1.2.", "4", "O" }, { "13", "trng-lvk1", "4.6.1.", "3", "O" } }; private static String sl, pid, tid, mval, status; public static void main(String args[]) { addTask(); } public static void addTask() { for (int k = 0; k < longValues.length; k++) { screen_dataz.put(k, longValues[k]); } Set<Entry<Integer, String[]>> mapSet = screen_dataz.entrySet(); Iterator<Entry<Integer, String[]>> mapIterator = mapSet.iterator(); while (mapIterator.hasNext()) { Entry<Integer, String[]> mapEntry = mapIterator.next(); Integer keyValue = mapEntry.getKey(); String[] value = mapEntry.getValue(); System.out.println(Arrays.toString(value)); } } }
One correction in your code:
You may want to update your for loop
as
for (int k=0; k<longValues.length; k++)
{
screen_dataz.put(k,longValues[k]);
}
First, change your for
loop to populate to screen_dataz
like this.
for (int k=0; k<longValues.length; k++)
{
screen_dataz.put(k,longValues[k]);
}
Next, make the below change:-
String keyValue = mapEntry.getKey().toString();
String value = Arrays.asList((Object[])mapEntry.getValue()).toString();
This will print your value properly.
Quite a few things to comment about this code.
First, the generic arguments of the parameterized type are incorrect. The map is currently storing Map<Long,Object[]>
however objects of type Object[][]
are added to the Map
. I assume you want to enter each Object[]
as a separate Entry
in the Map
.
for (int k=0; k<longValues.length; k++)
{
screen_dataz.put(k,longValues[k]);
}
The second piece to look at is the iteration over the Map
entries. Instead of using the Iterator
use a for..each
loop.
for(Entry<Integer,Object[]> entry: screen_dataz.entrySet()){
//repetitive task
}
Final Output
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
public class TaskList
{
private static HashMap<Integer, Object[]> dataz = new HashMap<Integer,Object[]>();
private static HashMap<Integer, Object[]> screen_dataz = new HashMap<Integer,Object[]>();
public final static Object[][] longValues = {{"10", "kstc-proc", "10.10.10.10.10.","5","O"},{"11", "proc-lvk1", "12.1.2.","4","O"},{"13", "trng-lvk1", "4.6.1.","3","O"}};
private static String sl,pid,tid,mval,status;
public static void main(String args[])
{
addTask();
}
public static void addTask()
{
for (int k=0; k<longValues.length; k++)
{
screen_dataz.put(k,longValues[k]);
}
for(Entry<Integer,Object[]> entry: screen_dataz.entrySet()){
System.out.println(entry.getKey());
for(Object obj: entry.getValue()){
System.out.println(obj.toString());
}
}
}
}
I think using screen_dataz.put(k,longValues[k]);
in a loop will help you. You could also use an Iterator for this.
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