How to add or insert ' (single quotes) for every string in a list in which strings are separated by commas using Java

Question

I have a list as below

[url1,url2,url3,url4] 

This list will be based on multiple selection from drop down list of HTML. So list size i.e., lis

Answer 1

Try this

    String[] str = {"url1","url2","url3","url4"};
    ArrayList<String> strList = new ArrayList<String>();
    for (String k:str)
        strList.add("'" +k+ "'");
    System.out.println("Printing the list");
    for(String k:strList)
        System.out.println(k);

Answer 2

1. Iterate the list (for/while).

2. For each element in the list append <element-of-list>. Hint: use append() on StringBuilder.

3. Truncate/substring the list to remove the last element added. Hint: use substring on String class.

Answer 3

for list you can convert this by Java 8

 list.stream().collect(Collectors.joining("','", "'", "'"));

Answer 4

If you have your elements in an array, you can do something like this:

import java.util.ArrayList;

class Test1{
    public static void main(String[] args) {
        String[] s = {"url1","url2","url3","url4"};

        ArrayList<String> sl = new ArrayList<String>();
        for (int i = 0; i < s.length; i++) {
            sl.add("'" + s[i] + "'"); 
        }
    }
}

Answer 5

import org.apache.commons.lang.StringUtils;
...
...
String arr[] = new String[4];
arr[0] = "my";
arr[1] = "name";
arr[2] = "is";
arr[3] = "baybora";

String join = "'" + StringUtils.join(arr,"','") + "'";

Result:

'my','name','is','baybora'

Answer 6

Also you can use Java8 built-in features for String concatenation and third-party libraries for wrapping each string in quotes.

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.runners.MockitoJUnitRunner;
import org.springframework.util.StringUtils;

import java.util.ArrayList;
import java.util.List;
import java.util.StringJoiner;

@RunWith(MockitoJUnitRunner.class)
public class StringJoinerTest {
    @Test
    public void testStringJoiner() {

        //init test data
        String s1 = "team1";
        String s2 = "team2";
        List<String> teams = new ArrayList<>(2);
        teams.add(s1);
        teams.add(s2);

        //configure StringJoiner
        //when some values will be added to joiner it will return string started with prefix "(" an finished with suffix ")"
        //between prefix and suffix values will be separated with delimiter ", "
        StringJoiner teamNames = new StringJoiner(", ", "(", ")");
        //if nothing has been added to the joiner it will return  this value ('')
        teamNames.setEmptyValue("(\'\')");

        //fill joiner with data
        for (String currentString : teams) {
            //if you need to wrap each string in single quotes you can do this via org.apache.commons.lang3.StringUtils#wrap
            // or org.springframework.util.StringUtils#quote
            teamNames.add(StringUtils.quote(currentString));
        }

        System.out.println(teamNames.toString());
    }
}