Java equivalent of PHP's implode(',' , array_filter( array () ))

Question

I often use this piece of code in PHP

$ordine[\'address\'] = implode(\', \', array_filter(array($cliente[\'cap\'], $cliente[\'citta\'], $cliente[\'provincia\'         


        

Answer 1

Here's my implode implementation:

/**
 * Implodes the specified items, gluing them using the specified glue replacing nulls with the specified
 * null placeholder.
 * @param glue              The text to use between the specified items.
 * @param nullPlaceholder   The placeholder to use for items that are <code>null</code> value.
 * @param items             The items to implode.
 * @return  A <code>String</code> containing the items in their order, separated by the specified glue.
 */
public static final String implode(String glue, String nullPlaceholder, String ... items) {
    StringBuilder sb = new StringBuilder();
    for (String item : items) {
        if (item != null) {
            sb.append(item);
        } else {
            sb.append(nullPlaceholder);
        }
        sb.append(glue);
    }
    return sb.delete(sb.length() - glue.length(), sb.length()).toString();
}

Answer 2

Use this simple function:

private String my_implode(String spacer, String[] in_array){

    String res = "";

    for (int i = 0 ; i < in_array.length ; i++) {

        if (!res.equals("")) {
            res += spacer;
        }
        res += in_array[i];
    }

    return res;
}

Use:

data_arr = {"d1", "d2", "d3"};
your_imploded_text = my_implode(",", data_arr);
// Output: your_imploded_text = "d1,d2,d3"

Answer 3

You'd have to add your strings to an ArrayList, remove empty ones, and format it accordingly:

public static String createAddressString( String street, String zip_code, String country) {
    List<String> list = new ArrayList<String>();
    list.add( street);
    list.add( zip_code);
    list.add( country);

    // Remove all empty values
    list.removeAll(Arrays.asList("", null));

    // If this list is empty, it only contained blank values
    if( list.isEmpty()) {
        return "";
    }

    // Format the ArrayList as a string, similar to implode
    StringBuilder builder = new StringBuilder();
    builder.append( list.remove(0));

    for( String s : list) {
        builder.append( ", ");
        builder.append( s);
    }

    return builder.toString();
}

Additionally, if you had String[], an array of strings, you can easily add them to an ArrayList:

String[] s;
List<String> list = new ArrayList<String>( Arrays.asList( s));

Answer 4

public static String implode(List<String> items, String separator) {

        if (items == null || items.isEmpty()) {
            return null;
        }
        String delimiter = "";
        StringBuilder builder = new StringBuilder();
        for (String item : items) {
            builder.append(delimiter).append(item);
            delimiter = separator;
        }
        return builder.toString();
    }

Answer 5

Why so serious? Try StringUtils.join(new String[] {"Hello", "World", "!"}, ", ") !

Answer 6

Here is an Android-specific answer that may be helpful to some:

String combined = TextUtils.join(",", new String[]{"Red", "Green", "Blue"});

// Result => Red,Green,Blue

Be sure to import the TextUtils class:

import android.text.TextUtils;