Compare using String.Contains() disregarding accents and case

Question

I know there’s already question, I even used the same title to call attention, but this one refers to C#, I’m having this problem in java, code:

//historico e searchC são ArrayLists, no caso do case utilizei o 
//toUpperCase() para igualar, porém, em questão de acentos ele não retorna 
//nenhum valor, mesmo estando exatamente igual ao valor da linha do array
int i = 0;
    for (String[] linha : historico){
        if(linha[2].contains(nome.toUpperCase())) {
            searchC.add(historico.get(i));

        }
        i++;
    }

Case the variable nome contains any type of accent, no value is returned in the searchC. Does anyone know how to make the comparison by disregarding accents and marry directly?

Answer 1

Adapting this reply from Soen, you can use the class Normalizer for that reason:

public boolean contanisIgnoreAccents(String a, String b) {
    String input1 = Normalizer.normalize(a, Normalizer.Form.NFD)
            .replaceAll("\\p{InCombiningDiacriticalMarks}+", "")
            .toLowerCase();

    String input2 = Normalizer.normalize(b, Normalizer.Form.NFD)
            .replaceAll("\\p{InCombiningDiacriticalMarks}+", "")
            .toLowerCase();

    return input1.contains(input2);
}

The comparison below:

System.out.println(contanisIgnoreAccents("Este é joao", "João"));
System.out.println(contanisIgnoreAccents("Onde está joÂo", "João"));

will return:

true
true

As can be seen in ideone: https://ideone.com/cJcF6M

The method checks whether the second string passed as argument is contained in the first.¹

^{¹ I edited the example to make clear the above definition, because if it is not used this way, the result may be shown wrong.}

Answer 2

I believe the simplest and quickest way would be to use the Stringutils of Apache Commons Lang.

In build.Radle adds dependency

dependencies {
  ...
  implementation 'org.apache.commons:commons-lang3:3.7'
}

Java code

import org.apache.commons.lang3.StringUtils;

public Boolean contanisIgnoreAccents(String a, String b) {

    // Remove os acentos e convert para minúsculo
    String str1 = StringUtils.stripAccents(a).toLowerCase();
    String str2 = StringUtils.stripAccents(b).toLowerCase();

    return str1.contains(str2);
}

public void onButtonClick {
    System.out.println(contanisIgnoreAccents("João", "joao"));
    System.out.println(contanisIgnoreAccents("João", "joÃo"));
}

Upshot

true
true

Kotlin code

fun contanisIgnoreAccents(a: String, b: String) = (
    StringUtils.stripAccents(a).toLowerCase().contains(StringUtils.stripAccents(b).toLowerCase())    
)