How to use the ICU4J library

Question

While I search the website for how to display RTL text correctly, I found this post about ICU , in fact I have no previous experience on how to use it. and almost no clear online resources.

Does any guy have previous experience using it? or at least tell me what I have to look for in order to get what I want?

Answer 1

Android N now offers ICU4J Android Framework API

Android N provides a subset of the ICU4J API through the android.icu package, not com.ibm.icu. Android frameworks may not disclose the ICU4J API for various reasons.

Here are some important notes:

• ICU4J APIs for Android do not include all ICU4J APIs.
• NDK developers should be aware that Android ICU4C is not supported.
• Android APIs do not replace Androids support for localizing resources .

Answer 2

Hi Adham. I have some experience with ICU4J. I tried to read the LTR text in Arabic and convert it to RTL Text I changed the numbers from English to Arabic and set the alignment to RTL. This is simple code that does the job. I hope my little experience helped you with this: demos on the ICU4J website

  PdfReader reader = new PdfReader(INPUTFILE); String txt=PdfTextExtractor.getTextFromPage(reader, 1); BiDiClass bidiClass = new BiDiClass(); String arabicNumber = bidiClass.englishToArabicNumber(txt); String out=bidiClass.makeLineLogicalOrder(arabicNumber, true); System.out.println(out); 

and this is BiDiClass

 import com.ibm.icu.text.Bidi; import com.ibm.icu.text.Normalizer; //Editor : Ibraheem Osama Mohamed /** * This class is an implementation the the ICU4J class. TextNormalize * will call this only if the ICU4J library exists in the classpath. * @author <a href="mailto:[e-mail]">Brian Carrier</a> * @version $Revision: 1.0 $ */ public class BiDiClass { private static final String REPLACE_CHARS = "0123456789."; private Bidi bidi; private StringBuilder sb = new StringBuilder(); /** * Constructor. */ public BiDiClass() { bidi = new Bidi(); /* We do not use bidi.setInverse() because that uses * Bidi.REORDER_INVERSE_NUMBERS_AS_L, which caused problems * in some test files. For example, a file had a line of: * 0 1 / ARABIC * and the 0 and 1 were reversed in the end result. * REORDER_INVERSE_LIKE_DIRECT is the inverse Bidi mode * that more closely reflects the Unicode spec. */ bidi.setReorderingMode(Bidi.REORDER_INVERSE_LIKE_DIRECT); } /** * Takes a line of text in presentation order and converts it to logical order. * @see TextNormalize.makeLineLogicalOrder(String, boolean) * * @param str String to convert * @param isRtlDominant RTL (right-to-left) will be the dominant text direction * @return The converted string */ public String makeLineLogicalOrder(String str, boolean isRtlDominant) { bidi.setPara(str, isRtlDominant?Bidi.RTL:Bidi.LTR, null); /* Set the mirror flag so that parentheses and other mirror symbols * are properly reversed, when needed. With this removed, lines * such as (CBA) in the PDF file will come out like )ABC( in logical * order. */ return bidi.writeReordered(Bidi.DO_MIRRORING); } //algorithm to change form English number to Arabic number public String englishToArabicNumber(String string){ char[] ch=string.toCharArray(); for (char c : ch) { if (REPLACE_CHARS.contains(String.valueOf(c))) { c = (char) ('\u0660' - '0' + c); } sb.append(c); } return sb.toString(); } /** * Normalize presentation forms of characters to the separate parts. * @see TextNormalize.normalizePres(String) * * @param str String to normalize * @return Normalized form */ public String normalizePres(String str) { StringBuilder builder = null; int p = 0; int q = 0; int strLength = str.length(); for (; q < strLength; q++) /* >>>*/ { // We only normalize if the codepoint is in a given range. // Otherwise, NFKC converts too many things that would cause // confusion. For example, it converts the micro symbol in // extended Latin to the value in the Greek script. We normalize // the Unicode Alphabetic and Arabic A&B Presentation forms. char c = str.charAt(q); if ((0xFB00 <= c && c <= 0xFDFF) || (0xFE70 <= c && c <= 0xFEFF))/* >>>*/ { if (builder == null) { builder = new StringBuilder(strLength * 2); } builder.append(str.substring(p, q)); // Some fonts map U+FDF2 differently than the Unicode spec. // They add an extra U+0627 character to compensate. // This removes the extra character for those fonts. if(c == 0xFDF2 && q > 0 && (str.charAt(q-1) == 0x0627 || str.charAt(q-1) == 0xFE8D)) { builder.append("\u0644\u0644\u0647"); } else { // Trim because some decompositions have an extra space, // such as U+FC5E builder.append( Normalizer.normalize(c, Normalizer.NFKC).trim()); } p = q + 1; } } if (builder == null) { return str; } else { builder.append(str.substring(p, q)); return builder.toString(); } } /** * Decomposes Diacritic characters to their combining forms. * * @param str String to be Normalized * @return A Normalized String */ public String normalizeDiac(String str) { StringBuilder retStr = new StringBuilder(); int strLength = str.length(); for (int i = 0; i < strLength; i++) /* >>>*/ { char c = str.charAt(i); if(Character.getType(c) == Character.NON_SPACING_MARK || Character.getType(c) == Character.MODIFIER_SYMBOL || Character.getType(c) == Character.MODIFIER_LETTER) { /* * Trim because some decompositions have an extra space, such as * U+00B4 */ retStr.append(Normalizer.normalize(c, Normalizer.NFKC).trim()); } else { retStr.append(str.charAt(i)); } } return retStr.toString(); } }