contains() 方法未按预期工作

Question

I am building a voice assistant for android, here this method retrieves contact names one by one and compares it to to SpeechToText input.

I am successfully getting the contact names, but when I am comparing it with my input text, nothing is happening.

Here is the code

private void callFromContact(String text_received, int index){

    Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null,null,null, null);
    while (phones.moveToNext())
    {
        String name=phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
        if(text_received.toLowerCase().contains(name)){
            String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
            contactNames.add(name);
            contactNumbers.add(phoneNumber);
        }
    }

Here for example I sending "call karan" as input, while debugging the name "Karan" comes up as the value of name variable, but when comparing it in if-statement, nothing happens, I mean the next statement is not executed, what might be the problem, help would be appreciated.

Answer 1

您还需要将name变量转换为小写，因为String.contains()方法区分大小写，所以call karan不包含Karan 。

Answer 2

if you just want to compare 2 strings, no matter if they are lower or upper case you should use equalsIgnoreCase . in your case:

if (text_received.equalsIgnoreCase(name))
{
   //...
}

EDIT: according to Bohuslav Burghard comment if you need to search a specific part of the string and make it ignore case, you can use regular expression with match function:

if (text_received.matches("(?i:.*" + name + ".*)"))
{
    //...
}

Answer 3

i used this method and it worked well. match() did not fullfiled my needs neither equal() nor equalToIgnore...

public static boolean containsIgnoreCase(String src, String what) {
    final int length = what.length();
    if (length == 0)
        return true; // Empty string is contained

    final char firstLo = Character.toLowerCase(what.charAt(0));
    final char firstUp = Character.toUpperCase(what.charAt(0));

    for (int i = src.length() - length; i >= 0; i--) {
        // Quick check before calling the more expensive regionMatches() method:
        final char ch = src.charAt(i);
        if (ch != firstLo && ch != firstUp)
            continue;

        if (src.regionMatches(true, i, what, 0, length))
            return true;
    }

    return false;
}