In this Java tutorial, you will learn How to Find Maximum Occurrence of Words from given Text File?
Here is a logic for getting top element:
- Create a class
CrunchifyComparablethat can store the String value of the word and the number of occurrences it appears. - Implement the Comparable interface for this class to
sort by occurrences first and then alphabeticallyif the number of occurrences is the same crunchifyFindMaxOccurrencemethod, you create a new List ofCrunchifyComparablefrom your original map. You add the entries of this to your List- Sort this list
- Take the n-first items of this list using subList
- Add Strings to the
List<String>and you return it
Another most read: Find more information on equals() and hashcode()
Java Code:
Create class CrunchifyFindMaxOccurrence.java. Put below code into file.
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;
}
}
Example-1 file:
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
Output:
Here is a IntelliJ IDEA console result. Run above program as a Java Application and you are will see result as below.
/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
Example-2 File:
this and and and then and this
Output:
Words # of Occurances and 4 this 2 then 1 Maixmum Occurance of Word in file: ==> and:4
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