Implementación Hashmap para contar las ocurrencias de cada carácter

Question

El siguiente código es para contar la ocurrencia de cada carácter y debe imprimir el conteo. Pero con el código que he intentado obtengo solo un 1, no sé los cambios que debo hacer. Por favor, ayúdame.

import java.io.BufferedReader; 
import java.io.DataInputStream; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.util.HashMap; 
import java.util.Map; 

class Count_CharMap { 
public static void main(String[] args) { 
    try 
    { 
     FileInputStream file = new FileInputStream("D:\\trial.txt"); 
     DataInputStream dis = new DataInputStream(file); 
     BufferedReader br = new BufferedReader(new InputStreamReader(dis)); 
     String Contents=""; 
     String str=""; 

     while ((Contents = br.readLine()) != null) { 
      str+=Contents; 
     } 

     char[]char_array =str.toCharArray(); 
     int count = 0; 
     char ch = char_array[count]; 
     Map<Character,Integer> charCounter=new HashMap<Character,Integer>(); 
     for(int i=0;i<str.length();i++) 
     { 
      if(charCounter.containsKey(char_array[i])) 
      { 
       charCounter.put(ch, charCounter.get(ch)+1); 
      } 
      else 
      { 
       charCounter.put(ch, 1); 
      } 
     } 

     for(Character key:charCounter.keySet()) 
     { 
      System.out.println(key+""+charCounter.get(key)); 
     } 
    } 
    catch(IOException e1){ 
     System.out.println(e1); 
    } 
    } 
} 

salida real debe ser como Si tengo en mi abcdabc trial.txt se debe imprimir una 2b 2c 2 d 1.

Answer 1

Te vas juego de caracteres ch como el mismo carácter a través de cada ejecución del bucle

Debería ser:

ch = char_array[i]; 
if(charCounter.containsKey(ch)){ 
    charCounter.put(ch, charCounter.get(ch)+1); 
} 
else 
{ 
    charCounter.put(ch, 1); 
} 

dentro del bucle.

Answer 2

import java.util.HashMap; 
import java.util.Map; 
... 
Map<String, Integer> freq = new HashMap<String, Integer>(); 
... 
int count = freq.containsKey(word) ? freq.get(word) : 0; 
freq.put(word, count + 1); 

Answer 3

Hai Todo El código siguiente es para contar la ocurrencia de cada carácter y debe imprimir el recuento. puede ser de ayuda .. Gracias por ver

paquete com.corejava;

import java.util.Map; 
import java.util.TreeMap; 

public class Test { 
    public static void main(String[] args) { 

     String str = "ramakoteswararao"; 

     char[] char_array = str.toCharArray(); 

     System.out.println("The Given String is : " + str); 

    Map<Character, Integer> charCounter = new TreeMap<Character, Integer>(); 

     for (char i : char_array) { 

    charCounter.put(i,charCounter.get(i) == null ? 1 : charCounter.get(i) + 1); 

     } 

    for (Character key : charCounter.keySet()) { 
    System.out.println("occurrence of '" + key + "' is "+ charCounter.get(key)); 
     } 

    } 

} 

Answer 4

Java 8 corrientes:

Map<String, Long> map = 
    Arrays.stream(string.split("")). 
    collect(Collectors.groupingBy(c -> c, Collectors.counting())); 

guayaba HashMultiset:

Multiset<Character> set = HashMultiset.create(Chars.asList("bbc".toCharArray())); 
assertEquals(2, set.count('b')); 

Answer 5

dentro del bucle

ch = char_array[i];
charCounter.put(charCounter.contains(ch)?charCounter.get(ch)+1:1);

Answer 6

import java.util.TreeMap; 

public class OccuranceDemo { 
    public static void main(String[] args) { 
     TreeMap<String , Integer> mp=new TreeMap(); 
     String s="rain rain go away"; 
     String[] arr = s.split(" "); 
     int length=arr.length; 
     for(int i=0;i<length;i++) 
     { 
     String h = arr[i]; 
     mp.put(h, mp.get(h)==null?1:mp.get(h)+1); 
    } 
    System.out.println(mp.get("go")); 
    } 
} 

Answer 7

String str=new String("aabbbcddddee"); 
    char[] ch=str.toCharArray(); 
    HashMap<Character,Integer> hm=new HashMap<Character,Integer>(); 
    for(char ch1:ch) 
    { 

     if(hm.containsKey(ch1)) 
     { 
      hm.put(ch1,hm.get(ch1)+1); 
     } 
     else 
     { 
      hm.put(ch1,1); 
     } 
    } 

    Set s1=hm.entrySet(); 
    Iterator itr=s1.iterator(); 

    while(itr.hasNext()) 
    { 
     Map.Entry m1=(Map.Entry)itr.next(); 
     System.out.println(m1); 
    } 

Answer 8

import java.util.*; 

public class Test { 
    public static void main(String[] args) { 

     String str = "STACKOVERFLOW"; 

     char[] char_array = str.toCharArray(); 

     System.out.println("The Given String is : " + str); 

    Map<Character, Integer> charCounter = new TreeMap<Character, Integer>(); 

     for (char i : char_array) { 

    charCounter.put(i,charCounter.get(i) == null ? 1 : charCounter.get(i) + 1); 

     } 

    for (Character key : charCounter.keySet()) { 
    System.out.println("occurrence of '" + key + "' is "+ charCounter.get(key)); 
     } 

    } 

}