读取excel表格问题，得到的值为null，这是什么原因？

[wuer2008]

代码如下：
public class ExcelReading {
private String url;
private int rows,columns;
private double [][]array;
private Cell[][]c;
private String[][]s;
public ExcelReading()
{

}
public String[][]readExcel(String URL)
{
this.url=URL;
try
{
InputStream is=new FileInputStream(url);
Workbook wb=Workbook.getWorkbook(is);
Sheet sh=wb.getSheet(0);
rows=sh.getRows();
int sheetsNumber=wb.getNumberOfSheets();
columns=sh.getColumns();
s=new String[rows][columns];
//array=new double[rows][columns];
System.out.println("rows="+rows+"col="+columns+"sheetnumber="+sheetsNumber);
for(int i=0;i<rows;i++){
for(int j=0;j<columns;j++){
c[i][j]=sh.getCell(i, j);
s[i][j]=c[i][j].getContents().toString().trim();
//array[i][j]=Double.parseDouble(s[i][j]);
}
}
wb.close();
}catch(Exception e)
{
e.getStackTrace();
}
return s;
}

}
测试代码：
public static void main(String[] args) {
// TODO Auto-generated method stub
ExcelReading er=new ExcelReading();
String url="D:/平差矩阵/矩阵.xls";
//double[][]db=er.readExcel(url);
String[][]ss=er.readExcel(url);
// for(int i=0;i<db.length;i++)
// for(int j=0;j<db[0].length;j++)
// System.out.println("db["+i+"]["+j+"]="+db[i][j]);
try{
for(int i=0;i<ss.length;i++)
for(int j=0;j<ss[0].length;j++)
System.out.println("ss["+i+"]["+j+"]="+ss[i][j]);
}catch(Exception e){e.getMessage();}

}

}
测试结果：rows=4 col=4 sheetnumber=3
ss[0][0]=null
ss[0][1]=null
ss[0][2]=null
ss[0][3]=null
ss[1][0]=null
ss[1][1]=null
ss[1][2]=null
ss[1][3]=null
ss[2][0]=null
ss[2][1]=null
ss[2][2]=null
ss[2][3]=null
ss[3][0]=null
ss[3][1]=null
ss[3][2]=null
ss[3][3]=null
请高手分析这是什么原因啊？小弟弄不明白！

[huxinyu929]

package simpletest;

import java.io.*;
import jxl.*;

public class TestXlsWrite{

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try{
			
			File f = new File("d:\\sun\\1.xls");
			InputStream is = new FileInputStream(f);
			Workbook wb = Workbook.getWorkbook(is);
			Sheet sheet0 = wb.getSheet(0);
			//Cell c00 = sheet0.getCell(0,0);
			for(int i=0;i<4;i++){
				for(int j=0;j<4;j++){
					Cell c00 = sheet0.getCell(i,j);
					System.out.println("ss["+i+","+j+"]="+c00.getContents());
				}
			}
			
			//String str00 = c00.getContents();
			//System.out.println(str00);
			
		}
		catch(Exception e){
			e.printStackTrace();
		}
	}

}

[huxinyu929]

ss[0,0]=1
ss[0,1]=1
ss[0,2]=1
ss[0,3]=1
ss[1,0]=2
ss[1,1]=2
ss[1,2]=2
ss[1,3]=2
ss[2,0]=3
ss[2,1]=3
ss[2,2]=3
ss[2,3]=3
ss[3,0]=4
ss[3,1]=4
ss[3,2]=4
ss[3,3]=4

[wuer2008]

多谢拉！知道哪里出错了！

[ilrxx]

那女的照片不是本人吧