How to convert hex to rgb using Java?

How can I conv开发者_JS百科ert hex color to RGB code in Java? Mostly in Google, samples are on how to convert from RGB to hex.

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

Color.decode("#FFCCEE");

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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 ) );
}

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

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For Android development, I use:

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

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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;
}

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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

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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;
}

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For JavaFX

import javafx.scene.paint.Color;

.

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

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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).

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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.

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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
}

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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();
}

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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

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The easiest way:

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

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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.

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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));

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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

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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;
}

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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;
}

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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);

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