Reputation: 8648

How to convert hex to rgb using Java?

How can I convert hex color to RGB code in Java? Mostly in Google, samples are on how to convert from RGB to hex.

Upvotes: 123

Answers (21)

Christoph Derszteler

Reputation: 146

If you need to decode a HEXA string in following format #RRGGBBAA, you can use the following:

private static Color convert(String hexa) {
  var value = Long.decode(hexa);
  return new Color(
    (int) (value >> 24) & 0xFF,
    (int) (value >> 16) & 0xFF,
    (int) (value >> 8) & 0xFF,
    (int) (value & 0xFF)
  );
}

Furthermore, if you want to ensure correct format, you can use this method to get a uniform result:

private static String format(String raw) {
  var builder = new StringBuilder(raw);
  if (builder.charAt(0) != '#') {
    builder.insert(0, '#');
  }
  if (builder.length() == 9) {
    return builder.toString();
  } else if (builder.length() == 7) {
    return builder.append("ff").toString();
  } else if (builder.length() == 4) {
    builder.insert(builder.length(), 'f');
  } else if (builder.length() != 5) {
    throw new IllegalStateException("unsupported format");
  }
  for (int index = 1; index <= 7; index += 2) {
    builder.insert(index, builder.charAt(index));
  }
  return builder.toString();
}

This method will turn every accepted format (#RGB, #RGBA, #RRGGBB, RGB, RGBA, RRGGBB) into #RRGGBBAA

Upvotes: 0

Sybuser

Reputation: 1374

Hex is base 16, so you can parse the string with parseLong using a radix of 16 :

Color newColor = new Color((int) Long.parseLong("FF7F0055", 16));

Upvotes: 1

Yeldar Nurpeissov

Reputation: 2296

For Android Kotlin developers:

"#FFF".longARGB()?.let{ Color.parceColor(it) }
"#FFFF".longARGB()?.let{ Color.parceColor(it) }

fun String?.longARGB(): String? {
    if (this == null || !startsWith("#")) return null
    
//    #RRGGBB or #AARRGGBB
    if (length == 7 || length == 9) return this

//    #RGB or #ARGB
    if (length in 4..5) {
        val rgb = "#${this[1]}${this[1]}${this[2]}${this[2]}${this[3]}${this[3]}"
        if (length == 5) {
            return "$rgb${this[4]}${this[4]}"
        }
        return rgb
    }

    return null
}

Upvotes: 1

user14310923

Reputation:

public static Color hex2Rgb(String colorStr) {
    try {
        // Create the color
        return new Color(
                // Using Integer.parseInt() with a radix of 16
                // on string elements of 2 characters. Example: "FF 05 E5"
                Integer.parseInt(colorStr.substring(0, 2), 16),
                Integer.parseInt(colorStr.substring(2, 4), 16),
                Integer.parseInt(colorStr.substring(4, 6), 16));
    } catch (StringIndexOutOfBoundsException e){
        // If a string with a length smaller than 6 is inputted
        return new Color(0,0,0);
    }
}

public static String rgbToHex(Color color) {
    //      Integer.toHexString(), built in Java method        Use this to add a second 0 if the
    //     .Get the different RGB values and convert them.     output will only be one character.
    return Integer.toHexString(color.getRed()).toUpperCase() + (color.getRed() < 16 ? 0 : "") + // Add String
            Integer.toHexString(color.getGreen()).toUpperCase() + (color.getGreen() < 16 ? 0 : "") +
            Integer.toHexString(color.getBlue()).toUpperCase() + (color.getBlue() < 16 ? 0 : "");
}

I think that this wil work.

Upvotes: 1

Amerousful

Reputation: 2545

The easiest way:

// 0000FF
public static Color hex2Rgb(String colorStr) {
    return new Color(Integer.valueOf(colorStr, 16));
}

Upvotes: 0

GTID

Reputation: 628

For shortened hex code like #fff or #000

int red = "colorString".charAt(1) == '0' ? 0 : 
     "colorString".charAt(1) == 'f' ? 255 : 228;  
int green =
     "colorString".charAt(2) == '0' ? 0 :  "colorString".charAt(2) == 'f' ?
     255 : 228;  
int blue = "colorString".charAt(3) == '0' ? 0 : 
     "colorString".charAt(3) == 'f' ? 255 : 228;

Color.rgb(red, green,blue);

Upvotes: -1

Abdul Saleem

Reputation: 10622

For JavaFX

import javafx.scene.paint.Color;

Color whiteColor = Color.valueOf("#ffffff");

Upvotes: 4

ucMax

Reputation: 5458

Here is another faster version that handles RGBA versions:

public static int hexToIntColor(String hex){
    int Alpha = Integer.valueOf(hex.substring(0, 2), 16);
    int Red = Integer.valueOf(hex.substring(2, 4), 16);
    int Green = Integer.valueOf(hex.substring(4, 6), 16);
    int Blue = Integer.valueOf(hex.substring(6, 8), 16);
    Alpha = (Alpha << 24) & 0xFF000000;
    Red = (Red << 16) & 0x00FF0000;
    Green = (Green << 8) & 0x0000FF00;
    Blue = Blue & 0x000000FF;
    return Alpha | Red | Green | Blue;
}

Upvotes: -1

Ben Hoskins

Reputation: 3698

Actually, there's an easier (built in) way of doing this:

Color.decode("#FFCCEE");

Upvotes: 365

dannrob

Reputation: 1069

If you don't want to use the AWT Color.decode, then just copy the contents of the method:

int i = Integer.decode("#FFFFFF");
int[] rgb = new int[]{(i >> 16) & 0xFF, (i >> 8) & 0xFF, i & 0xFF};

Integer.decode handles the # or 0x, depending on how your string is formatted

Upvotes: 0

Ian Newland

Reputation: 1744

Here is a version that handles both RGB and RGBA versions:

/**
 * Converts a hex string to a color. If it can't be converted null is returned.
 * @param hex (i.e. #CCCCCCFF or CCCCCC)
 * @return Color
 */
public static Color HexToColor(String hex) 
{
    hex = hex.replace("#", "");
    switch (hex.length()) {
        case 6:
            return new Color(
            Integer.valueOf(hex.substring(0, 2), 16),
            Integer.valueOf(hex.substring(2, 4), 16),
            Integer.valueOf(hex.substring(4, 6), 16));
        case 8:
            return new Color(
            Integer.valueOf(hex.substring(0, 2), 16),
            Integer.valueOf(hex.substring(2, 4), 16),
            Integer.valueOf(hex.substring(4, 6), 16),
            Integer.valueOf(hex.substring(6, 8), 16));
    }
    return null;
}

Upvotes: 13

Andrew

Reputation: 37969

The other day I'd been solving the similar issue and found convenient to convert hex color string to int array [alpha, r, g, b]:

 /**
 * Hex color string to int[] array converter
 *
 * @param hexARGB should be color hex string: #AARRGGBB or #RRGGBB
 * @return int[] array: [alpha, r, g, b]
 * @throws IllegalArgumentException
 */

public static int[] hexStringToARGB(String hexARGB) throws IllegalArgumentException {

    if (!hexARGB.startsWith("#") || !(hexARGB.length() == 7 || hexARGB.length() == 9)) {

        throw new IllegalArgumentException("Hex color string is incorrect!");
    }

    int[] intARGB = new int[4];

    if (hexARGB.length() == 9) {
        intARGB[0] = Integer.valueOf(hexARGB.substring(1, 3), 16); // alpha
        intARGB[1] = Integer.valueOf(hexARGB.substring(3, 5), 16); // red
        intARGB[2] = Integer.valueOf(hexARGB.substring(5, 7), 16); // green
        intARGB[3] = Integer.valueOf(hexARGB.substring(7), 16); // blue
    } else hexStringToARGB("#FF" + hexARGB.substring(1));

    return intARGB;
}

Upvotes: -1

Rich S

Reputation: 3453

Lots of these solutions work, but this is an alternative.

String hex="#00FF00"; // green
long thisCol=Long.decode(hex)+4278190080L;
int useColour=(int)thisCol;

If you don't add 4278190080 (#FF000000) the colour has an Alpha of 0 and won't show.

Upvotes: 1

Naveen

Reputation: 830

you can do it simply as below:

 public static int[] getRGB(final String rgb)
{
    final int[] ret = new int[3];
    for (int i = 0; i < 3; i++)
    {
        ret[i] = Integer.parseInt(rgb.substring(i * 2, i * 2 + 2), 16);
    }
    return ret;
}

For Example

getRGB("444444") = 68,68,68   
getRGB("FFFFFF") = 255,255,255

Upvotes: 5

dragunfli

Reputation: 24

To elaborate on the answer @xhh provided, you can append the red, green, and blue to format your string as "rgb(0,0,0)" before returning it.

/**
* 
* @param colorStr e.g. "#FFFFFF"
* @return String - formatted "rgb(0,0,0)"
*/
public static String hex2Rgb(String colorStr) {
    Color c = new Color(
        Integer.valueOf(hexString.substring(1, 3), 16), 
        Integer.valueOf(hexString.substring(3, 5), 16), 
        Integer.valueOf(hexString.substring(5, 7), 16));

    StringBuffer sb = new StringBuffer();
    sb.append("rgb(");
    sb.append(c.getRed());
    sb.append(",");
    sb.append(c.getGreen());
    sb.append(",");
    sb.append(c.getBlue());
    sb.append(")");
    return sb.toString();
}

Upvotes: 0

Todd Davies

Reputation: 5522

For Android development, I use:

int color = Color.parseColor("#123456");

Upvotes: 29

MattRS

Reputation: 428

A hex color code is #RRGGBB

RR, GG, BB are hex values ranging from 0-255

Let's call RR XY where X and Y are hex character 0-9A-F, A=10, F=15

The decimal value is X*16+Y

If RR = B7, the decimal for B is 11, so value is 11*16 + 7 = 183

public int[] getRGB(String rgb){
    int[] ret = new int[3];
    for(int i=0; i<3; i++){
        ret[i] = hexToInt(rgb.charAt(i*2), rgb.charAt(i*2+1));
    }
    return ret;
}

public int hexToInt(char a, char b){
    int x = a < 65 ? a-48 : a-55;
    int y = b < 65 ? b-48 : b-55;
    return x*16+y;
}

Upvotes: 4

Andrew Beck

Reputation: 439

public static void main(String[] args) {
    int hex = 0x123456;
    int r = (hex & 0xFF0000) >> 16;
    int g = (hex & 0xFF00) >> 8;
    int b = (hex & 0xFF);
}

Upvotes: 43

xhh

Reputation: 4032

I guess this should do it:

/**
 * 
 * @param colorStr e.g. "#FFFFFF"
 * @return 
 */
public static Color hex2Rgb(String colorStr) {
    return new Color(
            Integer.valueOf( colorStr.substring( 1, 3 ), 16 ),
            Integer.valueOf( colorStr.substring( 3, 5 ), 16 ),
            Integer.valueOf( colorStr.substring( 5, 7 ), 16 ) );
}

Upvotes: 179

Samuel

Reputation: 17171

Hexidecimal color codes are already rgb. The format is #RRGGBB

Upvotes: -3

Ignacio Vazquez-Abrams

Reputation: 798676

Convert it to an integer, then divmod it twice by 16, 256, 4096, or 65536 depending on the length of the original hex string (3, 6, 9, or 12 respectively).

Upvotes: 1

How to convert hex to rgb using Java?

Answers (21)

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