问题场景

今天在review代码的时候，发现对于ITEXT 表格的指定列合并还可以升级下，支持重复的字段出现合并。

比较

ITEXT 表格的指定列合并-升级版：方法简单，且支持 ‘A,A,B,C,A,D,D,D,E’，即字符串A可以重复不间断出现；
ITEXT 表格的指定列合并：方法略微复杂，且不支持 ‘A,A,B,C,A,D,D,D,E’，只支持 ‘A,A,B,C,D,D,D,E’，即字符串如果有重复的只能连续出现在一起。

CODE

需要导入的包：itext-pdfa-5.5.6.jar、itext-xtra-5.5.6.jar、itext-5.5.6.jar、itext-asian.jar

package itext.a14;

import com.itextpdf.text.*;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;

import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * Created on 2017/8/15
 * Author: youxingyang.
 */
public class A14 {
    public static String split = "<brb>";
    public static void main(String[] args) {
        Document document = new Document(PageSize.A4, 48, 48, 60, 65);

        try {
            PdfWriter pdfWriter = PdfWriter.getInstance(document, new FileOutputStream("A14.pdf"));
            document.open();
            // 设置字体
            BaseFont bfCN = BaseFont.createFont("STSongStd-Light", "UniGB-UCS2-H", false);
            // 正文的字体
            Font headFont = new Font(bfCN, 12f, Font.BOLD, BaseColor.ORANGE);
            Font textFont = new Font(bfCN, 12f, Font.NORMAL, BaseColor.BLUE);

            //添加测试数据
            List<String[]> list = new ArrayList<>();
            for (int i = 0; i < 24; i++) {
                String[] arr = new String[4];
                String value;
                if (i < 4) {
                    value = "A";
                } else if (i >= 4 && i < 6) {
                    value = "B";
                } else if (i >= 6 && i < 8) {
                    value = "C";
                } else if (i >= 8 && i < 13) {
                    value = "D";
                } else if (i == 13 || i == 14) {
                    value = "A";
                } else if (i > 14 && i < 16) {
                    value = "E";
                } else if (i == 17) {
                    value = "F";
                } else {
                    value = "G";
                }
                arr[0] = "0" + i;
                arr[1] = value;
                arr[2] = "2" + i;
                arr[3] = "3" + i;
                list.add(arr);
            }

            //复制要合并的列
            List<String> ListIn = new ArrayList<>();
            for (String[] aList : list) {
                ListIn.add(aList[1]);
            }
            //根据算法改变合并列的值
            List<String> changeList = changeList(ListIn);

            //改变该列后把它复制到原来的list
            for (int i = 0; i < changeList.size(); i++) {
                String[] arr = list.get(i);
                arr[1] = changeList.get(i);
                list.set(i, arr);
            }

            document.newPage();
            //建立一个4列的表格
            PdfPTable table = new PdfPTable(4);
            String[] titleArr = {"第1列", "合并列", "第3列", "第4列"};
            //加表格头部
            addTitle1(table, titleArr, headFont);
            //加表格内容
            addContent1(table, list, textFont);
            document.add(table);
            document.close();
        } catch (DocumentException | IOException e){
            e.printStackTrace();
        }
    }

    private static void addContent1(PdfPTable table, List<String[]> list, Font textFont) {
        //表格数据内容
        for (String[] str : list) {
            for (int j = 0; j < str.length; j++) {
                String value = str[j];
                if (value != null) {
                    Paragraph paragraph01;
                    int spanNum = 1;
                    if (j == 1 && value.contains(split)) {
                        spanNum = Integer.parseInt(value.split(split)[1]);
                        paragraph01 = new Paragraph(value.split(split)[0], textFont);
                    } else {
                        paragraph01 = new Paragraph(value, textFont);
                    }
                    paragraph01.setAlignment(1);
                    PdfPCell cell = new PdfPCell();
                    cell.setHorizontalAlignment(PdfPCell.ALIGN_CENTER);
                    cell.setVerticalAlignment(PdfPCell.ALIGN_MIDDLE);//然并卵
                    cell.setPaddingTop(-2f);//把字垂直居中
                    cell.setPaddingBottom(8f);//把字垂直居中
                    cell.addElement(paragraph01);
                    cell.setRowspan(spanNum);
                    table.addCell(cell);
                }
            }
        }
    }

    private static void addTitle1(PdfPTable table, String[] titleArr, Font headFont) {
        for (String aTitleArr : titleArr) {
            Paragraph p = new Paragraph(aTitleArr, headFont);
            PdfPCell cell = new PdfPCell();
            p.setAlignment(1);
            cell.setHorizontalAlignment(PdfPCell.ALIGN_CENTER);
            cell.setVerticalAlignment(PdfPCell.ALIGN_MIDDLE);//然并卵
            cell.setPaddingTop(-2f);//把字垂直居中
            cell.setPaddingBottom(8f);//把字垂直居中
            cell.addElement(p);
            table.addCell(cell);
        }
    }

    /**
     * 改变合并列的值
     * @param drugList 内容支持 'A,A,B,C,D,D,D,E' 支持 'A,A,B,C,A,D,D,D,E'
     * @return
     */
    private static List<String> changeList(List<String> drugList) {
        List<String> drugListCopy = new ArrayList<String>();
        drugListCopy.addAll(drugList);

        int nullNum = 0;
        for (int i = 0; i < drugList.size(); i++) {
            if (i > 0) {
                if (drugList.get(i).equals(drugList.get(i - 1))) {
                    drugListCopy.set(i, null);
                    nullNum++;
                } else {
                    if (nullNum > 0) {
                        int start = i - nullNum - 1;
                        drugListCopy.set(start, drugList.get(start) + split + (nullNum + 1));
                        nullNum = 0;
                    }
                }

				// 处理某一列值都相同的情况
                if (nullNum > 0) {
                    int start = i - nullNum;
                    drugListCopy.set(start, drugList.get(start) + split + (nullNum + 1));
                }
            }
        }
        return drugListCopy;
    }
}

效果