En Java, ¿cómo encontrar la ocurrencia máxima de palabras del archivo de texto?

Publicado: 2021-09-13
En Java, ¿cómo encontrar la ocurrencia máxima de palabras del archivo de texto?

En este tutorial de Java, aprenderá ¿Cómo encontrar la ocurrencia máxima de palabras de un archivo de texto dado?

Aquí hay una lógica para obtener el elemento superior:

  1. Cree una clase CrunchifyComparable que pueda almacenar el valor de cadena de la palabra y la cantidad de veces que aparece.
  2. Implemente la interfaz Comparable para que esta clase sort by occurrences first and then alphabetically si el número de ocurrencias es el mismo
  3. crunchifyFindMaxOccurrence , crea una nueva Lista de CrunchifyComparable a partir de su mapa original. Agregas las entradas de este a tu Lista
  4. ordenar esta lista
  5. Tome los n-primeros elementos de esta lista usando subList
  6. Agrega Strings a la List<String> y lo devuelves

Another most read : Encuentre más información sobre equals() y hashcode()

Código Java:

Cree la clase CrunchifyFindMaxOccurrence.java. Ponga el siguiente código en el archivo.

Java
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package crunchify . com . tutorials ;
 
import java . io . * ;
import java . util . * ;
 
public class CrunchifyFindMaxOccurrence {
/**
* @author Crunchify.com
* In Java How to Find Maximum Occurrence of Words from Text File?
*/
public static void main ( String [ ] args ) throws FileNotFoundException , IOException {
// File: An abstract representation of file and directory pathnames.
// User interfaces and operating systems use system-dependent pathname strings to name files and directories.
// This class presents an abstract, system-independent view of hierarchical pathnames.
File file = new File ( "/Users/app/Download/crunchify.txt" ) ;
// BufferedReader: Reads text from a character-input stream, buffering characters so as to provide for the efficient reading of characters, arrays, and lines.
// The buffer size may be specified, or the default size may be used.
// The default is large enough for most purposes.
BufferedReader bufferedReader = null ;
bufferedReader = new BufferedReader ( new FileReader ( file ) ) ;
String inputLine = null ;
// Map: An object that maps keys to values. A map cannot contain duplicate keys; each key can map to at most one value.
Map < String , Integer > crunchifyMap = new HashMap < > ( ) ;
try {
while ( ( inputLine = bufferedReader . readLine ( ) ) ! = null ) {
// split(): Splits this string around matches of the given regular expression.
// This method works as if by invoking the two-argument split method with the given expression and a limit argument of zero.
// Trailing empty strings are therefore not included in the resulting array.
String [ ] words = inputLine . split ( "[ \n\t\r.,;:!?(){}]" ) ;
for ( String word : words ) {
String key = word . toLowerCase ( ) ; // remove .toLowerCase for Case Sensitive result.
if ( key . length ( ) > 0 ) {
if ( crunchifyMap . get ( key ) == null ) {
crunchifyMap . put ( key , 1 ) ;
} else {
int value = crunchifyMap . get ( key ) . intValue ( ) ;
value ++ ;
crunchifyMap . put ( key , value ) ;
}
}
}
}
// Set: A collection that contains no duplicate elements.
// More formally, sets contain no pair of elements e1 and e2 such that e1.equals(e2),
// and at most one null element. As implied by its name, this interface models the mathematical set abstraction.
Set < Map . Entry < String , Integer > > entrySet = crunchifyMap . entrySet ( ) ;
crunchifyPrint ( "Words" + "\t\t" + "# of Occurances" ) ;
for ( Map . Entry < String , Integer > entry : entrySet ) {
crunchifyPrint ( entry . getKey ( ) + "\t\t" + entry . getValue ( ) ) ;
}
List <String> myTopOccurrence = crunchifyFindMaxOccurrence ( crunchifyMap , 1 ) ;
crunchifyPrint ( "\nMaximum Occurrence of Word in file: " ) ;
for ( String result : myTopOccurrence ) {
crunchifyPrint ( "==> " + result ) ;
}
// IOException: Signals that an I/O exception of some sort has occurred.
// This class is the general class of exceptions produced by failed or interrupted I/O operations.
} catch ( IOException error ) {
crunchifyPrint ( "Invalid File" ) ;
} finally {
bufferedReader . close ( ) ;
}
}
private static void crunchifyPrint ( String s ) {
System . out . println ( s ) ;
}
/**
* @param map = All Words in map
* @param n   = How many top elements you want to print? If n=1 it will print the highest occurrence word. If n=2 it
*            will print top 2 highest occurrence words.
* @returns list of String
*/
public static List <String> crunchifyFindMaxOccurrence ( Map < String , Integer > map , int n ) {
List <CrunchifyComparable> l = new ArrayList < > ( ) ;
for ( Map . Entry < String , Integer > entry : map . entrySet ( ) )
l . add ( new CrunchifyComparable ( entry . getKey ( ) , entry . getValue ( ) ) ) ;
// sort(): Sorts the specified list into ascending order, according to the natural ordering of its elements.
// All elements in the list must implement the Comparable interface. Furthermore, all elements in the list must be mutually comparable
// (that is, e1.compareTo(e2) must not throw a ClassCastException for any elements e1 and e2 in the list).
Collections . sort ( l ) ;
List <String> list = new ArrayList < > ( ) ;
// subList(): Returns a view of the portion of this list between the specified fromIndex,
// inclusive, and toIndex, exclusive. (If fromIndex and toIndex are equal, the returned list is empty.)
// The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa.
// The returned list supports all of the optional list operations supported by this list.
for ( CrunchifyComparable w : l . subList ( 0 , n ) )
list . add ( w . wordFromFile + ":" + w . numberOfOccurrence ) ;
return list ;
}
}
 
class CrunchifyComparable implements Comparable <CrunchifyComparable> {
public String wordFromFile ;
public int numberOfOccurrence ;
public CrunchifyComparable ( String wordFromFile , int numberOfOccurrence ) {
super ( ) ;
this . wordFromFile = wordFromFile ;
this . numberOfOccurrence = numberOfOccurrence ;
}
@Override
public int compareTo ( CrunchifyComparable arg0 ) {
int crunchifyCompare = Integer . compare ( arg0 . numberOfOccurrence , this . numberOfOccurrence ) ;
return crunchifyCompare ! = 0 ? crunchifyCompare : wordFromFile . compareTo ( arg0 . wordFromFile ) ;
}
@Override
public int hashCode ( ) {
final int uniqueNumber = 19 ;
int crunchifyResult = 9 ;
crunchifyResult = uniqueNumber * crunchifyResult + numberOfOccurrence ;
// hasCode(): Returns a hash code for this string. The hash code for a String object is computed as
//       s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
//
// using int arithmetic, where s[i] is the ith character of the string, n is the length of the string,
// and ^ indicates exponentiation. (The hash value of the empty string is zero.)
crunchifyResult = uniqueNumber * crunchifyResult + ( ( wordFromFile == null ) ? 0 : wordFromFile . hashCode ( ) ) ;
return crunchifyResult ;
}
// Override: Indicates that a method declaration is intended to override a method declaration in a supertype.
// If a method is annotated with this annotation type compilers are required
// to generate an error message unless at least one of the following conditions hold:
// The method does override or implement a method declared in a supertype.
// The method has a signature that is override-equivalent to that of any public method declared in Object.
@Override
public boolean equals ( Object crunchifyObj ) {
if ( this == crunchifyObj )
return true ;
if ( crunchifyObj == null )
return false ;
if ( getClass ( ) ! = crunchifyObj . getClass ( ) )
return false ;
CrunchifyComparable other = ( CrunchifyComparable ) crunchifyObj ;
if ( numberOfOccurrence ! = other . numberOfOccurrence )
return false ;
if ( wordFromFile == null ) {
if ( other . wordFromFile ! = null )
return false ;
} else if ( ! wordFromFile . equals ( other . wordFromFile ) )
return false ;
return true ;
}
}

Ejemplo-1 archivo:

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Crunchify is the largest free , premium , technical & blogging resource site for beginners , who are passionate & have the desire to excel in the online world . Attracting over 16 million monthly users , we are leading & trusted tech + blogging resource for all . We also help clients transform their great ideas into reality !
 
Crunchify , Crunchify , Crunchify . com

Producción:

Aquí hay un resultado de la consola IntelliJ IDEA. Ejecute el programa anterior como una aplicación Java y verá el resultado como se muestra a continuación.

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/ Library / Java / JavaVirtualMachines / jdk - 15.jdk / Contents / Home / bin / java - javaagent : / Applications / IntelliJ IDEA . app / Contents / lib / idea_rt . jar = 50339 : / Applications / IntelliJ IDEA . app / Contents / bin - Dfile . encoding = UTF - 8
- classpath / Users / app / crunchify / github / CrunchifyTutorials / target / classes : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / zxing - 2.1.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - logging - 1.1.2.jar
: / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - collections - 3.2.1.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / javax . mail . jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - io - 2.4.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - lang - 2.6.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - configuration - 1.9.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / log4j - 1.2.17.jar : / Users / app / crunchify / github / CrunchifyTutorials / WebContent / WEB - INF / lib / commons - beanutils - 1.8.3.jar
: / Users / app / Library / Application Support / JetBrains / IntelliJIdea2021 . 2 / javascript / extLibs / http_code . jquery . com_jquery - 3.6.0.js : / Users / app / . m2 / repository / org / glassfish / javax . json / 1.1.4 / javax . json - 1.1.4.jar : / Users / app / . m2 / repository / com / github / wnameless / json - flattener / 0.2.2 / json - flattener - 0.2.2.jar : / Users / app / . m2 / repository / com / eclipsesource / minimal - json / minimal - json / 0.9.4 / minimal - json - 0.9.4.jar : / Users / app / . m2 / repository / com / github / wnameless / json / json - flattener / 0.12.0 / json - flattener - 0.12.0.jar
: / Users / app / . m2 / repository / com / fasterxml / jackson / core / jackson - databind / 2.12.0 / jackson - databind - 2.12.0.jar : / Users / app / . m2 / repository / com / fasterxml / jackson / core / jackson - annotations / 2.12.0 / jackson - annotations - 2.12.0.jar : / Users / app / . m2 / repository / com / fasterxml / jackson / core / jackson - core / 2.12.0 / jackson - core - 2.12.0.jar
: / Users / app / . m2 / repository / org / apache / commons / commons - text / 1.9 / commons - text - 1.9.jar : / Users / app / . m2 / repository / com / github / wnameless / json / json - base / 2.0.0 / json - base - 2.0.0.jar : / Users / app / . m2 / repository / commons - io / commons - io / 2.10.0 / commons - io - 2.10.0.jar
: / Users / app / . m2 / repository / com / google / code / gson / gson / 2.8.7 / gson - 2.8.7.jar : / Users / app / . m2 / repository / net / jodah / expiringmap / 0.5.9 / expiringmap - 0.5.9.jar : / Users / app / . m2 / repository / org / apache / httpcomponents / httpclient / 4.5.13 / httpclient - 4.5.13.jar : / Users / app / . m2 / repository / org / apache / httpcomponents / httpcore / 4.4.13 / httpcore - 4.4.13.jar
: / Users / app / . m2 / repository / commons - codec / commons - codec / 1.11 / commons - codec - 1.11.jar : / Users / app / . m2 / repository / org / json / json / 20210307 / json - 20210307.jar : / Users / app / . m2 / repository / net / spy / spymemcached / 2.12.3 / spymemcached - 2.12.3.jar : / Users / app / . m2 / repository / com / whalin / Memcached - Java - Client / 3.0.2 / Memcached - Java - Client - 3.0.2.jar
: / Users / app / . m2 / repository / commons - pool / commons - pool / 1.5.6 / commons - pool - 1.5.6.jar : / Users / app / . m2 / repository / com / googlecode / xmemcached / xmemcached / 2.4.7 / xmemcached - 2.4.7.jar : / Users / app / . m2 / repository / com / paypal / sdk / rest - api - sdk / 1.14.0 / rest - api - sdk - 1.14.0.jar
: / Users / app / . m2 / repository / org / apache / commons / commons - dbcp2 / 2.8.0 / commons - dbcp2 - 2.8.0.jar : / Users / app / . m2 / repository / org / apache / commons / commons - pool2 / 2.8.1 / commons - pool2 - 2.8.1.jar : / Users / app / . m2 / repository / commons - dbcp / commons - dbcp / 20030825.184428 / commons - dbcp - 20030825.184428.jar : / Users / app / . m2 / repository / javax / ws / rs / javax . ws . rs - api / 2.1.1 / javax . ws . rs - api - 2.1.1.jar : / Users / app / . m2 / repository / org / hamcrest / hamcrest - all / 1.3 / hamcrest - all - 1.3.jar : / Users / app / . m2 / repository / org / apache / logging / log4j / log4j - core / 2.14.1 / log4j - core - 2.14.1.jar : / Users / app / . m2 / repository / org / apache / logging / log4j / log4j - api / 2.14.1 / log4j - api - 2.14.1.jar
: / Users / app / . m2 / repository / com / google / guava / guava / 30.1.1 - jre / guava - 30.1.1 - jre . jar : / Users / app / . m2 / repository / com / google / guava / failureaccess / 1.0.1 / failureaccess - 1.0.1.jar : / Users / app / . m2 / repository / com / google / guava / listenablefuture / 9999.0 - empty - to - avoid - conflict - with - guava / listenablefuture - 9999.0 - empty - to - avoid - conflict - with - guava . jar : / Users / app / . m2 / repository / com / google / code / findbugs / jsr305 / 3.0.2 / jsr305 - 3.0.2.jar
: / Users / app / . m2 / repository / org / checkerframework / checker - qual / 3.8.0 / checker - qual - 3.8.0.jar : / Users / app / . m2 / repository / com / google / errorprone / error_prone_annotations / 2.5.1 / error_prone_annotations - 2.5.1.jar : / Users / app / . m2 / repository / com / google / j2objc / j2objc - annotations / 1.3 / j2objc - annotations - 1.3.jar : / Users / app / . m2 / repository / com / googlecode / json - simple / json - simple / 1.1.1 / json - simple - 1.1.1.jar : / Users / app / . m2 / repository / junit / junit / 4.10 / junit - 4.10.jar : / Users / app / . m2 / repository / org / hamcrest / hamcrest - core / 1.1 / hamcrest - core - 1.1.jar : / Users / app / . m2 / repository / commons - net / commons - net / 3.8.0 / commons - net - 3.8.0.jar : / Users / app / . m2 / repository / org / ow2 / asm / asm / 9.1 / asm - 9.1.jar : / Users / app / . m2 / repository / axis / axis / 1.4 / axis - 1.4.jar : / Users / app / . m2 / repository / org / apache / axis / axis - jaxrpc / 1.4 / axis - jaxrpc - 1.4.jar : / Users / app / . m2 / repository / axis / axis - wsdl4j / 1.5.1 / axis - wsdl4j - 1.5.1.jar : / Users / app / . m2 / repository / commons - beanutils / commons - beanutils / 1.9.4 / commons - beanutils - 1.9.4.jar : / Users / app / . m2 / repository / commons - collections / commons - collections / 3.2.2 / commons - collections - 3.2.2.jar : / Users / app / . m2 / repository / org / apache / commons / commons - collections4 / 4.4 / commons - collections4 - 4.4.jar : / Users / app / . m2 / repository / org / apache / commons / commons - configuration2 / 2.7 / commons - configuration2 - 2.7.jar
: / Users / app / . m2 / repository / commons - discovery / commons - discovery / 0.5 / commons - discovery - 0.5.jar : / Users / app / . m2 / repository / org / apache / commons / commons - lang3 / 3.12.0 / commons - lang3 - 3.12.0.jar : / Users / app / . m2 / repository / commons - logging / commons - logging / 1.2 / commons - logging - 1.2.jar : / Users / app / . m2 / repository / commons - logging / commons - logging - api / 1.1 / commons - logging - api - 1.1.jar : / Users / app / . m2 / repository / javax / mail / javax . mail - api / 1.6.2 / javax . mail - api - 1.6.2.jar : / Users / app / . m2 / repository / javax / mail / mail / 1.4.7 / mail - 1.4.7.jar : / Users / app / . m2 / repository / javax / activation / activation / 1.1 / activation - 1.1.jar : / Users / app / . m2 / repository / javax / xml / jaxrpc - api / 1.1 / jaxrpc - api - 1.1.jar : / Users / app / . m2 / repository / org / apache / axis / axis - saaj / 1.4 / axis - saaj - 1.4.jar : / Users / app / . m2 / repository / wsdl4j / wsdl4j / 1.6.3 / wsdl4j - 1.6.3.jar : / Users / app / . m2 / repository / com / google / zxing / core / 3.4.1 / core - 3.4.1.jar : / Users / app / . m2 / repository / org / apache / commons / commons - compress / 1.20 / commons - compress - 1.20.jar : / Users / app / . m2 / repository / mysql / mysql - connector - java / 8.0.25 / mysql - connector - java - 8.0.25.jar : / Users / app / . m2 / repository / com / google / protobuf / protobuf - java / 3.11.4 / protobuf - java - 3.11.4.jar
: / Users / app / . m2 / repository / ch / qos / logback / logback - classic / 1.3.0 - alpha5 / logback - classic - 1.3.0 - alpha5 . jar : / Users / app / . m2 / repository / ch / qos / logback / logback - core / 1.3.0 - alpha5 / logback - core - 1.3.0 - alpha5 . jar : / Users / app / . m2 / repository / com / sun / mail / javax . mail / 1.6.2 / javax . mail - 1.6.2.jar : / Users / app / . m2 / repository / edu / washington / cs / types / checker / checker - framework / 1.7.0 / checker - framework - 1.7.0.jar : / Users / app / . m2 / repository / commons - validator / commons - validator / 1.7 / commons - validator - 1.7.jar : / Users / app / . m2 / repository / commons - digester / commons - digester / 2.1 / commons - digester - 2.1.jar : / Users / app / . m2 / repository / org / springframework / spring - context / 5.3.8 / spring - context - 5.3.8.jar : / Users / app / . m2 / repository / org / springframework / spring - aop / 5.3.8 / spring - aop - 5.3.8.jar : / Users / app / . m2 / repository / org / springframework / spring - beans / 5.3.8 / spring - beans - 5.3.8.jar
: / Users / app / . m2 / repository / org / springframework / spring - core / 5.3.8 / spring - core - 5.3.8.jar : / Users / app / . m2 / repository / org / springframework / spring - jcl / 5.3.8 / spring - jcl - 5.3.8.jar : / Users / app / . m2 / repository / org / springframework / spring - expression / 5.3.8 / spring - expression - 5.3.8.jar : / Users / app / . m2 / repository / org / springframework / spring - context - support / 5.3.8 / spring - context - support - 5.3.8.jar : / Users / app / . m2 / repository / org / slf4j / slf4j - api / 1.7.31 / slf4j - api - 1.7.31.jar : / Users / app / . m2 / repository / org / slf4j / jul - to - slf4j / 1.7.31 / jul - to - slf4j - 1.7.31.jar : / Users / app / . m2 / repository / org / slf4j / jcl - over - slf4j / 1.7.31 / jcl - over - slf4j - 1.7.31.jar : / Users / app / . m2 / repository / org / slf4j / log4j - over - slf4j / 1.7.31 / log4j - over - slf4j - 1.7.31.jar crunchify . com . tutorials . CrunchifyFindMaxOccurrence
 
 
Words # of Occurances
com 1
largest 1
clients 1
technical 1
passionate 1
leading 1
for 2
their 1
we 2
into 1
transform 1
premium 1
world 1
are 2
attracting 1
have 1
free 1
crunchify 4
over 1
tech 1
all 1
desire 1
blogging 2
resource 2
in 1
16 1
& 3
is 1
also 1
ideas 1
+ 1
great 1
users 1
the 3
excel 1
help 1
site 1
million 1
trusted 1
beginners 1
monthly 1
online 1
reality 1
to 1
who 1
 
Maximum Occurrence of Word in file :
== > crunchify : 4
 
Process finished with exit code 0

Ejemplo-2 Archivo:

1
this and and and then and this
Producción:
1
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3
4
5
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7
Words # of Occurances
and 4
this 2
then 1
 
Maixmum Occurance of Word in file :
== > and : 4

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