Example usage for java.lang String charAt

Introduction

In this page you can find the example usage for java.lang String charAt.

Prototype

public char charAt(int index)

Source Link

Document

Returns the char value at the specified index.

Usage

From source file:Main.java

/**
 * Checking whether a peer ID is Shadow style or not is a bit tricky.
 * /*from  w w w .j  a  v  a  2  s . c o  m*/
 * The BitTornado peer ID convention code is explained here:
 *   http://forums.degreez.net/viewtopic.php?t=7070
 *   
 * The main thing we are interested in is the first six characters.
 * Although the other characters are base64 characters, there's no
 * guarantee that other clients which follow that style will follow
 * that convention (though the fact that some of these clients use
 * BitTornado in the core does blur the lines a bit between what is
 * "style" and what is just common across clients).
 * 
 * So if we base it on the version number information, there's another
 * problem - there isn't the use of absolute delimiters (no fixed dash
 * character, for example).
 * 
 * There are various things we can do to determine how likely the peer
 * ID is to be of that style, but for now, I'll keep it to a relatively
 * simple check.
 * 
 * We'll assume that no client uses the fifth version digit, so we'll
 * expect a dash. We'll also assume that no client has reached version 10
 * yet, so we expect the first two characters to be "letter,digit".
 * 
 * We've seen some clients which don't appear to contain any version
 * information, so we need to allow for that.
 */
public static boolean isShadowStyle(String peer_id) {
    if (peer_id.charAt(5) != '-') {
        return false;
    }
    if (!Character.isLetter(peer_id.charAt(0))) {
        return false;
    }
    if (!(Character.isDigit(peer_id.charAt(1)) || peer_id.charAt(1) == '-')) {
        return false;
    }

    // Find where the version number string ends.
    int last_ver_num_index = 4;
    for (; last_ver_num_index > 0; last_ver_num_index--) {
        if (peer_id.charAt(last_ver_num_index) != '-') {
            break;
        }
    }

    // For each digit in the version string, check it is a valid version identifier.
    char c;
    for (int i = 1; i <= last_ver_num_index; i++) {
        c = peer_id.charAt(i);
        if (c == '-') {
            return false;
        }
        if (decodeAlphaNumericChar(c) == null) {
            return false;
        }
    }

    return true;
}

From source file:Main.java

public static int binaryToAlgorism(String binary) {
    int max = binary.length();
    int result = 0;
    for (int i = max; i > 0; i--) {
        char c = binary.charAt(i - 1);
        int algorism = c - '0';
        result += Math.pow(2, max - i) * algorism;
    }/*w  w  w .  ja v a  2s . c om*/
    return result;
}

From source file:Main.java

public static byte[] decodeBytes(String str) {
    byte[] bytes = new byte[str.length() / 2];
    for (int i = 0; i < str.length(); i += 2) {
        char c = str.charAt(i);
        bytes[i / 2] = (byte) ((c - 'a') << 4);
        c = str.charAt(i + 1);/*w w w  .  ja  v  a 2  s .  c om*/
        bytes[i / 2] += (c - 'a');
    }
    return bytes;
}

From source file:Main.java

public static char binaryBlockOf4ToHex(String input) {
    int sum = 0;// w  w  w .  java 2 s .  co m
    int first = (input.charAt(0) - 48) * 8;
    int second = (input.charAt(1) - 48) * 4;
    int third = (input.charAt(2) - 48) * 2;
    int fourth = (input.charAt(3) - 48);
    sum = first + second + third + fourth;
    if (sum == 10)
        return 'A';
    else if (sum == 11)
        return 'B';
    else if (sum == 12)
        return 'C';
    else if (sum == 13)
        return 'D';
    else if (sum == 14)
        return 'E';
    else if (sum == 15)
        return 'F';
    else
        return (char) (sum + 48);
}

From source file:Main.java

public static boolean isUpperCase(String s) {
    int len = s.length();
    for (int i = 0; i < len; i++) {
        char ch = s.charAt(i);
        if (Character.toUpperCase(ch) != ch)
            return false;
    }/*from  w  w w.  ja v  a 2s .  co m*/
    return len != 0;
}

From source file:Main.java

/**
 * Tests if all characters are XML space (<tt>'\t'</tt>, <tt>'\r'</tt>,
 * <tt>'\n'</tt>, <tt>' '</tt>).
 * /*  w  w w . ja v a  2 s. co m*/
 * @param s characters to be tested
 * @return <code>true</code> if test is successful; <code>false</code>
 *         otherwise
 */
public static final boolean isXMLSpace(String s) {
    for (int c = s.length(); --c >= 0;)
        if (!isXMLSpace(s.charAt(c)))
            return false;
    return true;
}

From source file:com.omnigon.aem.common.utils.StringUtils.java

public static String shortenString(String src, int length, boolean addEllipses) {
    if (isNotBlank(src) && src.length() > length) {
        if (addEllipses) {
            String sub = src.substring(0, length);
            char last = sub.charAt(sub.length() - 1);

            return PUNCTUATION.contains(Character.toString(last)) ? sub : sub + ELLIPSES;
        } else {//from ww w .j  a v a  2  s  . c o  m

            return src.substring(0, length);
        }
    }

    return src;
}

From source file:Main.java

public static String getRandomString(int length) {
    String retVal = "1234567890";
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < length; i++)
        sb.append(retVal.charAt(random.nextInt(retVal.length())));
    return sb.toString();
}

From source file:Main.java

public static int hex2color(String color) {
    if (TextUtils.isEmpty(color)) {
        color = "#ffffff";
    }//  w  ww  .j a va2s  . co  m

    int result;
    if (color.charAt(0) != '#') {
        color = "#" + color;
    }
    result = Color.parseColor(color);
    return result;
}

From source file:Main.java

private static String camelCase2Upper(String s) {
    String r = "";
    boolean u = false;
    for (int i = 0; i < s.length(); i++) {
        char c = s.charAt(i);
        char C = Character.toUpperCase(c);
        if (Character.isUpperCase(c)) {
            r = r + (u ? ("_" + C) : C);
        } else {/*  w w  w  . j  a  va2s  . c  o  m*/
            u = true;
            r = r + C;
        }
    }
    return r;
}