Java使用IText生产PDF时，中文标点符号出现在行首的问题处理

Java使用IText生成PDF时，中文标点符号出现在行首的问题处理

使用itext 5进行html转成pdf时，标点符号出现在某一行的开头但这种情况下显然不符合中文书写的规则，主要问题出在itext中的DefaultSplitCharacter类，该方法主要用来判断字符是否为可拆分字符。

itext 版本：5.5.13

解决办法：
1、可以通过修改源码的方式，可以参考
如何修改jar包源码以及解决iText生成pdf时中文标点存在行首问题

2、在自己项目中创建与itext中DefaultSplitCharacter相同的包路径，并在该包下重新DefaultSplitCharacter类,能这样处理的原因，与类的加载顺序有关。
在这里插入图片描述

package com.itextpdf.text.pdf;

import com.itextpdf.text.SplitCharacter;

public class DefaultSplitCharacter implements SplitCharacter {

    /**
     * An instance of the default SplitCharacter.
     */
    public static final SplitCharacter DEFAULT = new DefaultSplitCharacter();

    // line of text cannot start or end with this character
    static final char u2060 = '\u2060'; // - ZERO WIDTH NO BREAK SPACE

    // a line of text cannot start with any following characters in
    // NOT_BEGIN_CHARACTERS[]
    static final char u30fb = '\u30fb'; // ・ - KATAKANA MIDDLE DOT
    static final char u2022 = '\u2022'; // • - BLACK SMALL CIRCLE (BULLET)
    static final char uff65 = '\uff65'; // ･ - HALFWIDTH KATAKANA MIDDLE DOT
    static final char u300d = '\u300d'; // 」 - RIGHT CORNER BRACKET
    static final char uff09 = '\uff09'; // ） - FULLWIDTH RIGHT PARENTHESIS
    static final char u0021 = '\u0021'; // ! - EXCLAMATION MARK
    static final char u0025 = '\u0025'; // % - PERCENT SIGN
    static final char u0029 = '\u0029'; // ) - RIGHT PARENTHESIS
    static final char u002c = '\u002c'; // , - COMMA
    static final char u002e = '\u002e'; // . - FULL STOP
    static final char u003f = '\u003f'; // ? - QUESTION MARK
    static final char u005d = '\u005d'; // ] - RIGHT SQUARE BRACKET
    static final char u007d = '\u007d'; // } - RIGHT CURLY
    static final char uff61 = '\uff61'; // ｡ - HALFWIDTH IDEOGRAPHIC FULL STOP

    static final char uff70 = '\uff70'; // ｰ - HALFWIDTH KATAKANA-HIRAGANA PROLONGED SOUND MARK
    static final char uff9e = '\uff9e'; // ﾞ - HALFWIDTH KATAKANA VOICED SOUND MARK
    static final char uff9f = '\uff9f'; // ﾟ - HALFWIDTH KATAKANA SEMI-VOICED SOUND MARK
    static final char u3001 = '\u3001'; // 、 - IDEOGRAPHIC COMMA
    static final char u3002 = '\u3002'; // 。 - IDEOGRAPHIC FULL STOP
    static final char uff0c = '\uff0c'; // ， - FULLWIDTH COMMA
    static final char uff0e = '\uff0e'; // ． - FULLWIDTH FULL STOP
    static final char uff1a = '\uff1a'; // ： - FULLWIDTH COLON
    static final char uff1b = '\uff1b'; // ； - FULLWIDTH SEMICOLON
    static final char uff1f = '\uff1f'; // ？ - FULLWIDTH QUESTION MARK
    static final char uff01 = '\uff01'; // ！ - FULLWIDTH EXCLAMATION MARK
    static final char u309b = '\u309b'; // ゛ - KATAKANA-HIRAGANA VOICED SOUND MARK
    static final char u309c = '\u309c'; // ゜ - KATAKANA-HIRAGANA SEMI-VOICED SOUND MARK
    static final char u30fd = '\u30fd'; // ヽ - KATAKANA ITERATION MARK

    static final char u2019 = '\u2019'; // ’ - RIGHT SINGLE QUOTATION MARK
    static final char u201d = '\u201d'; // ” - RIGHT DOUBLE QUOTATION MARK
    static final char u3015 = '\u3015'; // 〕 - RIGHT TORTOISE SHELL BRACKET
    static final char uff3d = '\uff3d'; // ］ - FULLWIDTH RIGHT SQUARE BRACKET
    static final char uff5d = '\uff5d'; // ｝ - FULLWIDTH RIGHT CURLY BRACKET
    static final char u3009 = '\u3009'; // 〉 - RIGHT ANGLE BRACKET
    static final char u300b = '\u300b'; // 》 - RIGHT DOUBLE ANGLE BRACKET
    static final char u300f = '\u300f'; // 』 - RIGHT WHITE CORNER BRACKET
    static final char u3011 = '\u3011'; // 】 - RIGHT BLACK LENTICULAR BRACKET
    static final char u00b0 = '\u00b0'; // ° - DEGREE SIGN
    static final char u2032 = '\u2032'; // ′ - PRIME
    static final char u2033 = '\u2033'; // ″ - DOUBLE PRIME

    static final char[] NOT_BEGIN_CHARACTERS = new char[] { u30fb, u2022, uff65, u300d, uff09, u0021, u0025, u0029,
            u002c, u002e, u003f, u005d, u007d, uff61, uff70, uff9e, uff9f, u3001, u3002, uff0c, uff0e, uff1a, uff1b,
            uff1f, uff01, u309b, u309c, u30fd, u2019, u201d, u3015, uff3d, uff5d, u3009, u300b, u300f, u3011, u00b0,
            u2032, u2033, u2060 };

    // a line of text cannot end with any following characters in
    // NOT_ENDING_CHARACTERS[]
    static final char u0024 = '\u0024'; // $ - DOLLAR SIGN
    static final char u0028 = '\u0028'; // ( - LEFT PARENTHESIS
    static final char u005b = '\u005b'; // [ - LEFT SQUARE BRACKET
    static final char u007b = '\u007b'; // { - LEFT CURLY BRACKET
    static final char u00a3 = '\u00a3'; // £ - POUND SIGN
    static final char u00a5 = '\u00a5'; // ¥ - YEN SIGN
    static final char u201c = '\u201c'; // “ - LEFT DOUBLE QUOTATION MARK
    static final char u2018 = '\u2018'; // ‘ - LEFT SINGLE QUOTATION MARK
    static final char u300a = '\u300a'; // 《 - LEFT DOUBLE ANGLE BRACKET
    static final char u3008 = '\u3008'; // 〈 - LEFT ANGLE BRACKET
    static final char u300c = '\u300c'; // 「 - LEFT CORNER BRACKET
    static final char u300e = '\u300e'; // 『 - LEFT WHITE CORNER BRACKET
    static final char u3010 = '\u3010'; // 【 - LEFT BLACK LENTICULAR BRACKET
    static final char u3014 = '\u3014'; // 〔 - LEFT TORTOISE SHELL BRACKET
    static final char uff62 = '\uff62'; // ｢ - HALFWIDTH LEFT CORNER BRACKET
    static final char uff08 = '\uff08'; // （ - FULLWIDTH LEFT PARENTHESIS
    static final char uff3b = '\uff3b'; // ［ - FULLWIDTH LEFT SQUARE BRACKET
    static final char uff5b = '\uff5b'; // ｛ - FULLWIDTH LEFT CURLY BRACKET
    static final char uffe5 = '\uffe5'; // ￥ - FULLWIDTH YEN SIGN
    static final char uff04 = '\uff04'; // ＄ - FULLWIDTH DOLLAR SIGN

    static final char[] NOT_ENDING_CHARACTERS = new char[] { u0024, u0028, u005b, u007b, u00a3, u00a5, u201c, u2018,
            u3008, u300a, u300c, u300e, u3010, u3014, uff62, uff08, uff3b, uff5b, uffe5, uff04, u2060 };



    @Override
    public boolean isSplitCharacter(int start, int current, int end, char[] cc, PdfChunk[] ck) {


        // Note: If you don't add an try/catch and there is an issue with
        // isSplitCharacter(), iText silently fails and
        // you have no idea there was a problem.
        try {

            char c = getCharacter(current, cc, ck);

            int next = current + 1;
            if (next < cc.length) {
                char charNext = getCharacter(next, cc, ck);
                for (char not_begin_character : NOT_BEGIN_CHARACTERS) {
                    if (charNext == not_begin_character) {
                        return false;
                    }
                }
            }

            for (char not_ending_character : NOT_ENDING_CHARACTERS) {
                if (c == not_ending_character) {
                    return false;
                }
            }

            if (c <= ' ' || c == '-' || c == '\u2010') {
                return true;
            }
            if (c < 0x2002)
                return false;
            return ((c >= 0x2002 && c <= 0x200b)
                    || (c >= 0x2e80 && c < 0xd7a0)
                    || (c >= 0xf900 && c < 0xfb00)
                    || (c >= 0xfe30 && c < 0xfe50)
                    || (c >= 0xff61 && c < 0xffa0));
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return true;
    }

    /**
     * Returns a character int the array (Note: modified from the iText default
     * version with the addition null check of '|| ck[Math.min(position, ck.length -
     * 1)] == null'.
     *
     * @param position position in the array
     * @param ck       chunk array
     * @param cc       the character array that has to be checked
     * @return the character
     */
    protected char getCharacter(int position, char[] cc, PdfChunk[] ck) {
        if (ck == null || ck[Math.min(position, ck.length - 1)] == null) {
            return cc[position];
        }
        return (char) ck[Math.min(position, ck.length - 1)].getUnicodeEquivalent(cc[position]);
    }
}