Table Rendering Issue with CJK Characters

[jiangood]

🐛 Bug Report: Incorrect Table Border Alignment

📄 Description

When using the Table component to display data that contains CJK (Chinese, Japanese, Korean) characters or other full-width symbols , the table borders become misaligned and broken.

🖥️ Environment

• spring-shell version: 3.4.x
• spring-boot version: 3.5.8
• java version: 17
• os: windows 10, Ubuntu 22

🔬 Steps to Reproduce

project that replicates the problem: https://github.com/jiangood/spring-shell-cjk-issue-demo

clone and run mvnw package && java -jar target/app.jar hi

• windows cmd

• windows powershell

• linux （by XShell)

project main code :

@Command
public class TestCommand {

    @Command
    public Table hi() {
        String[][] data = {
                {"name", "addr"},
                {"Alexander", "America"},
                {"张三",  "中国北京"},
        };

        TableModel model = new ArrayTableModel(data);
        TableBuilder builder = new TableBuilder(model)
                .addFullBorder(BorderStyle.fancy_light);
        Table table = builder.build();

        return table;
    }
}

---

💡 Possible Solution

Use Jline utils to calculate the width

AttributedString.fromAnsi(text).columnLength()

I found two place to fix it (spring-shell version: 3.4.x)

1. AutoSizeConstraints

   public class AutoSizeConstraints implements SizeConstraints {
   
       @Override
       public Extent width(String[] raw, int tableWidth, int nbColumns) {
           int max = 0;
           int min = 0;
           for (String line : raw) {
               String[] words = line.split(" ");
               for (String word : words) {
                   // -- min = Math.max(min, word.length());
                   // ++
                   min = Math.max(min, AttributedString.fromAnsi(word).columnLength());
               }
               // -- max = Math.max(max, line.length());
               // ++
               max = Math.max(max, AttributedString.fromAnsi(line).columnLength());
           }
           return new Extent(min, max);
       }
   }

2. SimpleHorizontalAligner

   public enum SimpleHorizontalAligner implements Aligner {
   
       left, center, right;
   
       @Override
       public String[] align(String[] text, int cellWidth, int cellHeight) {
           String[] result = new String[cellHeight];
           for (int i = 0; i < cellHeight; i++) {
               String line = (i < text.length && text[i] != null) ? text[i].trim() : "";
   
               // -- int paddingToDistribute = cellWidth - line.length();
               // ++
               int paddingToDistribute = cellWidth - AttributedString.fromAnsi(line).columnLength(); 
   
               int padLeft;
               int padRight;
   
               switch (this) {
                   case center: {
                       int carry = paddingToDistribute % 2;
                       paddingToDistribute = paddingToDistribute - carry;
                       padLeft = padRight = paddingToDistribute / 2;
                       padRight += carry;
                       break;
                   }
                   case right: {
                       padLeft = paddingToDistribute;
                       padRight = 0;
                       break;
                   }
                   case left: {
                       padLeft = 0;
                       padRight = paddingToDistribute;
                       break;
                   }
                   default:
                       throw new AssertionError();
               }
               StringBuilder sb = new StringBuilder(cellWidth);
               for (int j = 0; j < padLeft; j++) {
                   sb.append(' ');
               }
               sb.append(line);
               for (int j = 0; j < padRight; j++) {
                   sb.append(' ');
               }
   
               result[i] = sb.toString();
           }
           return result;
       }
   
   }