java - 如何使用 ICU4J 库

Question

当我在网站上搜索如何正确显示 RTL 文本时，我找到了 this post关于ICU图书馆，事实上我以前没有任何使用它的经验。而且几乎没有明确的在线资源。

这里有人有使用它的经验吗？或者至少告诉我必须搜索什么才能得到我想要的东西？

Answer 1

嗨，Adham，我在 ICU4J 方面经验不足，我正在尝试阅读 LTR 阿拉伯语文本并将其转换为 RTL 文本 我将数字从英文更改为阿拉伯数字并将对齐方式设置为 RTL 这是一个完成工作的简单代码我希望我的一点经验对您有所帮助这是 ICU4J 站点中的 demos

        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);

这是 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:carrier@digital-evidence.org">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();
    }

      }