Question

我在网站上搜索有关如何正确显示RTL文字时我发现this post关于ICU库的问题，实际上我之前没有任何经验如何使用它。而且几乎没有明确的在线资源。

此处的任何人都有过使用它的经验吗？或者至少告诉我我要搜索什么来获得我想要的东西？

Answer 1

嗨，Adham我对ICU4J有一点经验我试图读取LTR阿拉伯语文本并将其转换为RTL Text 我将数字从英文更改为阿拉伯数字，并将对齐设置为RTL这是一个简单的代码，我希望我的小经验可以帮助你，这是ICU4J网站中的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();
    }

      }

Answer 2

Android N现在提供 ICU4J Android Framework APIs

Android N通过android.icu包而不是com.ibm.icu公开了ICU4J API的子集。 Android框架可能会出于各种原因选择不公开ICU4J API

以下是一些需要注意的重要事项：

ICU4J Android框架API不包含所有ICU4J API。
NDK开发人员应该知道不支持Android ICU4C。
Android框架中的API不会取代Android对localizing with resources的支持。

如何使用ICU4J库

2 个答案: