在Java的System.out中以表格式输出
在Java的System.out中以表格式输出
提问于 2010-04-30 22:32:56
我从数据库中获取结果，并希望将数据以Java标准输出中的表的形式输出
我尝试使用\t，但我想要的第一列的长度非常可变。
有没有办法在像output这样漂亮的表格中显示出来呢？
回答 6
Stack Overflow用户
回答已采纳
发布于 2010-04-30 22:37:04
使用System.out.format。您可以像这样设置字段的长度：
System.out.format("%32s%10d%16s", string1, int1, string2);这会将string1、int1和string2分别填充为32、10和16个字符。
有关语法的更多信息，请参阅java.util.Formatter的Javadoc (System.out.format在内部使用Formatter )。
Stack Overflow用户
发布于 2013-12-25 18:42:37
使用j-text-utils，您可以打印到控制台的一个表，如下所示：
它就像这样简单：
TextTable tt = new TextTable(columnNames, data);
tt.printTable(); API还允许排序和行号...
Stack Overflow用户
发布于 2016-12-31 15:28:59
我的答案可能会很晚，但这里有一个简单而通用的解决方案
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));
}
}使用这种输出
+----------------------------------------+----------------------------------------+----------------------------------------+----------------------------------------+
| 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 |
+----------------------------------------+----------------------------------------+----------------------------------------+----------------------------------------+页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/2745206
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