我创建了一个可能对你有用的 TablePrinter 类
主要方法sn-p：
TablePrinter table = new TablePrinter("MyTest","OtherTest","SillyColumn");
table.addRow("ABC","DEF","GHIJKLMNOPQRSTUVWXYZ");
table.addRow("This is a test","of the","TablePrinter class");
table.print();
结果：
C:\junk>javac TablePrinter.java
C:\junk>java TablePrinter
TablePrinter test driver
| MyTest | OtherTest | SillyColumn |
-----------------------------------------------------
| ABC | DEF | GHIJKLMNOPQRSTUVWXYZ |
| This is a test | of the | TablePrinter class |
C:\junk>
班级：
import java.util.ArrayList;
/**
* The table printer classes takes a matrix of data and prints it.
*/
class TablePrinter {
/**
* The row class represents one row of data.
* Yes, it's just a wrapper for String[], but it helps
* keep it simple.
*/
private static class Row {
String[] data;
Row(String[] v) { data = v; }
}
/**
* Contains column header and max width information
*/
private static class Col {
String name;
int maxWidth;
}
// matrix information
Col[] cols;
ArrayList<Row> rows;
/**
* Constructor - pass in columns as an array, or hard coded
*/
public TablePrinter(String... names) {
cols = new Col[names.length];
for(int i = 0; i < cols.length; i++) {
cols[i] = new Col();
cols[i].name = names[i];
cols[i].maxWidth = names[i].length();
}
rows = new ArrayList<Row>();
}
/**
* Adds a row - pass in an array or hard coded
*/
public void addRow(String... values) {
if(values.length != cols.length) {
throw new IllegalArgumentException("invalid number of columns in values");
}
Row row = new Row(values);
rows.add(row);
for(int i = 0; i < values.length; i++) {
if(values[i].length() > cols[i].maxWidth) {
cols[i].maxWidth = values[i].length();
}
}
}
/**
* Helper method to make sure column headers and
* row information are printed the same
*/
private void print(String v, int w) {
System.out.print(" ");
System.out.print(v);
System.out.print(spaces(w - v.length()));
System.out.print(" |");
}
/**
* Ugly, poorly documented print method.
* All pieces of production code should have some
* methods that you have to decipher. This fulfils that requirement.
*/
public void print() {
System.out.print("|");
for(Col col : cols) {
print(col.name, col.maxWidth);
}
System.out.println("");
int numDashes = cols.length*3 + 1;
for(Col col : cols) numDashes += col.maxWidth;
// TODO make columns have + instead of -
System.out.println(dashes(numDashes));
for(Row row : rows) {
System.out.print("|");
int i = 0;
for(String v : row.data) {
print(v,cols[i++].maxWidth);
}
System.out.println("");
}
System.out.println("");
}
// print a specific number of spaces for padding
private static String spaces(int i) {
StringBuilder sb = new StringBuilder();
while(i --> 0) sb.append(" ");
return sb.toString();
}
// print a specific number of dashes
private static String dashes(int i) {
StringBuilder sb = new StringBuilder();
while(i --> 0) sb.append("-");
return sb.toString();
}
// test driver
public static void main(String[] args) {
System.out.println("TablePrinter test driver");
TablePrinter table = new TablePrinter("MyTest","OtherTest","SillyColumn");
table.addRow("ABC","DEF","GHIJKLMNOPQRSTUVWXYZ");
table.addRow("This is a test","of the","TablePrinter class");
table.print();
}
}