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URIEncoderDecoder.javaAPI DocAndroid 1.5 API8691Wed May 06 22:41:04 BST 2009java.net

URIEncoderDecoder

public class URIEncoderDecoder extends Object
This class is used to encode a string using the format required by {@code application/x-www-form-urlencoded} MIME content type. It contains helper methods used by the URI class, and performs encoding and decoding in a slightly different way than {@code URLEncoder} and {@code URLDecoder}.
since
Android 1.0

Fields Summary
static final String
digits
static final String
encoding
Constructors Summary
Methods Summary
static java.lang.Stringdecode(java.lang.String s)
Decodes the string argument which is assumed to be encoded in the {@code x-www-form-urlencoded} MIME content type using the UTF-8 encoding scheme.

'%' and two following hex digit characters are converted to the equivalent byte value. All other characters are passed through unmodified.

e.g. "A%20B%20C %24%25" -> "A B C $%"

Called from URI.getXYZ() methods

param
s java.lang.String The encoded string.
return
java.lang.String The decoded version.


        StringBuffer result = new StringBuffer();
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        for (int i = 0; i < s.length();) {
            char c = s.charAt(i);
            if (c == '%") {
                out.reset();
                do {
                    if (i + 2 >= s.length()) {
                        throw new IllegalArgumentException(Msg.getString(
                                "K01fe", i)); //$NON-NLS-1$
                    }
                    int d1 = Character.digit(s.charAt(i + 1), 16);
                    int d2 = Character.digit(s.charAt(i + 2), 16);
                    if (d1 == -1 || d2 == -1) {
                        throw new IllegalArgumentException(Msg.getString(
                                "K01ff", s.substring(i, i + 3), //$NON-NLS-1$
                                String.valueOf(i)));
                    }
                    out.write((byte) ((d1 << 4) + d2));
                    i += 3;
                } while (i < s.length() && s.charAt(i) == '%");
                result.append(out.toString(encoding));
                continue;
            }
            result.append(c);
            i++;
        }
        return result.toString();
static java.lang.StringencodeOthers(java.lang.String s)
Other characters, which are Unicode chars that are not US-ASCII, and are not ISO Control or are not ISO Space chars are not preserved. They are converted into their hexidecimal value prepended by '%'.

For example: Euro currency symbol -> "%E2%82%AC".

Called from URI.toASCIIString()

param
s java.lang.String the string to be converted
return
java.lang.String the converted string

        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < s.length(); i++) {
            char ch = s.charAt(i);
            if (ch <= 127) {
                buf.append(ch);
            } else {
                byte[] bytes = new String(new char[] { ch }).getBytes(encoding);
                for (int j = 0; j < bytes.length; j++) {
                    buf.append('%");
                    buf.append(digits.charAt((bytes[j] & 0xf0) >> 4));
                    buf.append(digits.charAt(bytes[j] & 0xf));
                }
            }
        }
        return buf.toString();
static java.lang.StringquoteIllegal(java.lang.String s, java.lang.String legal)
All characters except letters ('a'..'z', 'A'..'Z') and numbers ('0'..'9') and legal characters are converted into their hexidecimal value prepended by '%'.

For example: '#' -> %23

Other characters, which are unicode chars that are not US-ASCII, and are not ISO Control or are not ISO Space chars, are preserved.

Called from {@code URI.quoteComponent()} (for multiple argument constructors)

param
s java.lang.String the string to be converted
param
legal java.lang.String the characters allowed to be preserved in the string s
return
java.lang.String the converted string

        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < s.length(); i++) {
            char ch = s.charAt(i);
            if ((ch >= 'a" && ch <= 'z")
                    || (ch >= 'A" && ch <= 'Z")
                    || (ch >= '0" && ch <= '9")
                    || legal.indexOf(ch) > -1
                    || (ch > 127 && !Character.isSpaceChar(ch) && !Character
                            .isISOControl(ch))) {
                buf.append(ch);
            } else {
                byte[] bytes = new String(new char[] { ch }).getBytes(encoding);
                for (int j = 0; j < bytes.length; j++) {
                    buf.append('%");
                    buf.append(digits.charAt((bytes[j] & 0xf0) >> 4));
                    buf.append(digits.charAt(bytes[j] & 0xf));
                }
            }
        }
        return buf.toString();
static voidvalidate(java.lang.String s, java.lang.String legal)
Validate a string by checking if it contains any characters other than: 1. letters ('a'..'z', 'A'..'Z') 2. numbers ('0'..'9') 3. characters in the legalset parameter 4. others (unicode characters that are not in US-ASCII set, and are not ISO Control or are not ISO Space characters)

called from {@code URI.Helper.parseURI()} to validate each component

param
s {@code java.lang.String} the string to be validated
param
legal {@code java.lang.String} the characters allowed in the String s

 //$NON-NLS-1$

                                                                                                                       
            
        for (int i = 0; i < s.length();) {
            char ch = s.charAt(i);
            if (ch == '%") {
                do {
                    if (i + 2 >= s.length()) {
                        throw new URISyntaxException(s, Msg.getString("K0313"), //$NON-NLS-1$
                                i);
                    }
                    int d1 = Character.digit(s.charAt(i + 1), 16);
                    int d2 = Character.digit(s.charAt(i + 2), 16);
                    if (d1 == -1 || d2 == -1) {
                        throw new URISyntaxException(s, Msg.getString("K0314", //$NON-NLS-1$
                                s.substring(i, i + 3)), i);
                    }

                    i += 3;
                } while (i < s.length() && s.charAt(i) == '%");

                continue;
            }
            if (!((ch >= 'a" && ch <= 'z") || (ch >= 'A" && ch <= 'Z")
                    || (ch >= '0" && ch <= '9") || legal.indexOf(ch) > -1 || (ch > 127
                    && !Character.isSpaceChar(ch) && !Character
                    .isISOControl(ch)))) {
                throw new URISyntaxException(s, Msg.getString("K00c1"), i); //$NON-NLS-1$
            }
            i++;
        }
static voidvalidateSimple(java.lang.String s, java.lang.String legal)

        for (int i = 0; i < s.length();) {
            char ch = s.charAt(i);
            if (!((ch >= 'a" && ch <= 'z") || (ch >= 'A" && ch <= 'Z")
                    || (ch >= '0" && ch <= '9") || legal.indexOf(ch) > -1)) {
                throw new URISyntaxException(s, Msg.getString("K00c1"), i); //$NON-NLS-1$
            }
            i++;
        }