Output in a table format in Java's System.out

Question

I\'m getting results from a database and want to output the data as a table in Java\'s standard output

I\'ve tried using \\t but the first column I want is very vari

Answer 1

Check this out. The author provides a simple but elegant solution which doesn't require any 3rd party library. http://www.ksmpartners.com/2013/08/nicely-formatted-tabular-output-in-java/

Answer 2

Use System.out.format . You can set lengths of fields like this:

System.out.format("%32s%10d%16s", string1, int1, string2);

This pads string1, int1, and string2 to 32, 10, and 16 characters, respectively.

See the Javadocs for java.util.Formatter for more information on the syntax (System.out.format uses a Formatter internally).

Answer 3

I may be very late for the Answer but here a simple and generic solution

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;

public class TableGenerator {

    private int PADDING_SIZE = 2;
    private String NEW_LINE = "\n";
    private String TABLE_JOINT_SYMBOL = "+";
    private String TABLE_V_SPLIT_SYMBOL = "|";
    private String TABLE_H_SPLIT_SYMBOL = "-";

    public String generateTable(List<String> headersList, List<List<String>> rowsList,int... overRiddenHeaderHeight)
    {
        StringBuilder stringBuilder = new StringBuilder();

        int rowHeight = overRiddenHeaderHeight.length > 0 ? overRiddenHeaderHeight[0] : 1; 

        Map<Integer,Integer> columnMaxWidthMapping = getMaximumWidhtofTable(headersList, rowsList);

        stringBuilder.append(NEW_LINE);
        stringBuilder.append(NEW_LINE);
        createRowLine(stringBuilder, headersList.size(), columnMaxWidthMapping);
        stringBuilder.append(NEW_LINE);


        for (int headerIndex = 0; headerIndex < headersList.size(); headerIndex++) {
            fillCell(stringBuilder, headersList.get(headerIndex), headerIndex, columnMaxWidthMapping);
        }

        stringBuilder.append(NEW_LINE);

        createRowLine(stringBuilder, headersList.size(), columnMaxWidthMapping);


        for (List<String> row : rowsList) {

            for (int i = 0; i < rowHeight; i++) {
                stringBuilder.append(NEW_LINE);
            }

            for (int cellIndex = 0; cellIndex < row.size(); cellIndex++) {
                fillCell(stringBuilder, row.get(cellIndex), cellIndex, columnMaxWidthMapping);
            }

        }

        stringBuilder.append(NEW_LINE);
        createRowLine(stringBuilder, headersList.size(), columnMaxWidthMapping);
        stringBuilder.append(NEW_LINE);
        stringBuilder.append(NEW_LINE);

        return stringBuilder.toString();
    }

    private void fillSpace(StringBuilder stringBuilder, int length)
    {
        for (int i = 0; i < length; i++) {
            stringBuilder.append(" ");
        }
    }

    private void createRowLine(StringBuilder stringBuilder,int headersListSize, Map<Integer,Integer> columnMaxWidthMapping)
    {
        for (int i = 0; i < headersListSize; i++) {
            if(i == 0)
            {
                stringBuilder.append(TABLE_JOINT_SYMBOL);   
            }

            for (int j = 0; j < columnMaxWidthMapping.get(i) + PADDING_SIZE * 2 ; j++) {
                stringBuilder.append(TABLE_H_SPLIT_SYMBOL);
            }
            stringBuilder.append(TABLE_JOINT_SYMBOL);
        }
    }


    private Map<Integer,Integer> getMaximumWidhtofTable(List<String> headersList, List<List<String>> rowsList)
    {
        Map<Integer,Integer> columnMaxWidthMapping = new HashMap<>();

        for (int columnIndex = 0; columnIndex < headersList.size(); columnIndex++) {
            columnMaxWidthMapping.put(columnIndex, 0);
        }

        for (int columnIndex = 0; columnIndex < headersList.size(); columnIndex++) {

            if(headersList.get(columnIndex).length() > columnMaxWidthMapping.get(columnIndex))
            {
                columnMaxWidthMapping.put(columnIndex, headersList.get(columnIndex).length());
            }
        }


        for (List<String> row : rowsList) {

            for (int columnIndex = 0; columnIndex < row.size(); columnIndex++) {

                if(row.get(columnIndex).length() > columnMaxWidthMapping.get(columnIndex))
                {
                    columnMaxWidthMapping.put(columnIndex, row.get(columnIndex).length());
                }
            }
        }

        for (int columnIndex = 0; columnIndex < headersList.size(); columnIndex++) {

            if(columnMaxWidthMapping.get(columnIndex) % 2 != 0)
            {
                columnMaxWidthMapping.put(columnIndex, columnMaxWidthMapping.get(columnIndex) + 1);
            }
        }


        return columnMaxWidthMapping;
    }

    private int getOptimumCellPadding(int cellIndex,int datalength,Map<Integer,Integer> columnMaxWidthMapping,int cellPaddingSize)
    {
        if(datalength % 2 != 0)
        {
            datalength++;
        }

        if(datalength < columnMaxWidthMapping.get(cellIndex))
        {
            cellPaddingSize = cellPaddingSize + (columnMaxWidthMapping.get(cellIndex) - datalength) / 2;
        }

        return cellPaddingSize;
    }

    private void fillCell(StringBuilder stringBuilder,String cell,int cellIndex,Map<Integer,Integer> columnMaxWidthMapping)
    {

        int cellPaddingSize = getOptimumCellPadding(cellIndex, cell.length(), columnMaxWidthMapping, PADDING_SIZE);

        if(cellIndex == 0)
        {
            stringBuilder.append(TABLE_V_SPLIT_SYMBOL); 
        }

        fillSpace(stringBuilder, cellPaddingSize);
        stringBuilder.append(cell);
        if(cell.length() % 2 != 0)
        {
            stringBuilder.append(" ");
        }

        fillSpace(stringBuilder, cellPaddingSize);

        stringBuilder.append(TABLE_V_SPLIT_SYMBOL); 

    }

    public static void main(String[] args) {
        TableGenerator tableGenerator = new TableGenerator();

        List<String> headersList = new ArrayList<>(); 
        headersList.add("Id");
        headersList.add("F-Name");
        headersList.add("L-Name");
        headersList.add("Email");

        List<List<String>> rowsList = new ArrayList<>();

        for (int i = 0; i < 5; i++) {
            List<String> row = new ArrayList<>(); 
            row.add(UUID.randomUUID().toString());
            row.add(UUID.randomUUID().toString());
            row.add(UUID.randomUUID().toString());
            row.add(UUID.randomUUID().toString());

            rowsList.add(row);
        }

        System.out.println(tableGenerator.generateTable(headersList, rowsList));
    }
}

With this kind of Output

+----------------------------------------+----------------------------------------+----------------------------------------+----------------------------------------+
|                   Id                   |                F-Name                  |                 L-Name                 |                  Email                 |
+----------------------------------------+----------------------------------------+----------------------------------------+----------------------------------------+
|  70a56f25-d42a-499c-83ac-50188c45a0ac  |  aa04285e-c135-46e2-9f90-988bf7796cd0  |  ac495ba7-d3c7-463c-8c24-9ffde67324bc  |  f6b5851b-41e0-4a4e-a237-74f8e0bff9ab  |
|  6de181ca-919a-4425-a753-78d2de1038ef  |  c4ba5771-ccee-416e-aebd-ef94b07f4fa2  |  365980cb-e23a-4513-a895-77658f130135  |  69e01da1-078e-4934-afb0-5afd6ee166ac  |
|  f3285f33-5083-4881-a8b4-c8ae10372a6c  |  46df25ed-fa0f-42a4-9181-a0528bc593f6  |  d24016bf-a03f-424d-9a8f-9a7b7388fd85  |  4b976794-aac1-441e-8bd2-78f5ccbbd653  |
|  ab799acb-a582-45e7-ba2f-806948967e6c  |  d019438d-0a75-48bc-977b-9560de4e033e  |  8cb2ad11-978b-4a67-a87e-439d0a21ef99  |  2f2d9a39-9d95-4a5a-993f-ceedd5ff9953  |
|  78a68c0a-a824-42e8-b8a8-3bdd8a89e773  |  0f030c1b-2069-4c1a-bf7d-f23d1e291d2a  |  7f647cb4-a22e-46d2-8c96-0c09981773b1  |  0bc944ef-c1a7-4dd1-9eef-915712035a74  |
+----------------------------------------+----------------------------------------+----------------------------------------+----------------------------------------+

Answer 4

Check out the class java.util.Formatter.

Answer 5

Because most of solutions is bit outdated I could also suggest asciitable which already available in maven (de.vandermeer:asciitable:0.3.2) and may produce very complicated configurations.

Features (by offsite):

• Text table with some flexibility for rules and content, alignment, format, padding, margins, and frames:
• add text, as often as required in many different formats (string, text provider, render provider, ST, clusters),
• removes all excessive white spaces (tabulators, extra blanks, combinations of carriage return and line feed),
• 6 different text alignments: left, right, centered, justified, justified last line left, justified last line right,
• flexible width, set for text and calculated in many different ways for rendering
• padding characters for left and right padding (configurable separately)
• padding characters for top and bottom padding (configurable separately)
• several options for drawing grids
• rules with different styles (as supported by the used grid theme: normal, light, strong, heavy)
• top/bottom/left/right margins outside a frame
• character conversion to generated text suitable for further process, e.g. for LaTeX and HTML

And usage still looks easy:

AsciiTable at = new AsciiTable();

at.addRule();
at.addRow("row 1 col 1", "row 1 col 2");
at.addRule();
at.addRow("row 2 col 1", "row 2 col 2");
at.addRule();

System.out.println(at.render()); // Finally, print the table to standard out.

Answer 6

Using j-text-utils you may print to console a table like:

And it as simple as:

TextTable tt = new TextTable(columnNames, data);                                                         
tt.printTable();   

The API also allows sorting and row numbering ...