Java String Join – Different ways

When we develop a web application, a lot of times,  we may need to join a list or an array with a space of comma. In Java, we have to write boilerplate code to do that.

To get rid of those, we can use the Apache common utils or guava utils. Refer the below code. It’s pretty simple if we use those utils effectively. Humans tend to make errors. So if we write the code for ourselves, we may cause some issues while doing those. All these utils and its methods are thoroughly tested and verified. So it’s good to use these unless reinvent yourself.


import com.google.common.base.Joiner;
import org.apache.commons.lang3.StringUtils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class StringJoinUtils {

    public static void main(String[] args) {
        List stringList = new ArrayList(Arrays.asList(new String[]{"Apple","Orange","Banana"}));
        //Apache commons
        System.out.println(StringUtils.join(stringList, ":"));
        //Guvava utils
        System.out.println(Joiner.on(":").join(stringList));
        //Java 8
        System.out.println(String.join(":", stringList));
    }
}


If we use Java 8, we can use the String.join method.

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