HSSFWorkbook类文件

首先从Workbook开始我们的POI编程之旅。要生成一个Workbook，需要用到HSSFWorkbook类文件，类定义如下：

• java.lang.Object
• org.apache.poi.hssf.usermodel.HSSFWorkbook
• public class HSSFWorkbook extends java.lang.Object

它有五个构造方法：

构建器
HSSFWorkbook() Creates new HSSFWorkbook from scratch (start here!)
HSSFWorkbook(java.io.InputStream s)
HSSFWorkbook(java.io.InputStream s, boolean preserveNodes) Companion to HSSFWorkbook(POIFSFileSystem), this constructs the POI filesystem around your inputstream.
HSSFWorkbook(POIFSFileSystem fs)
HSSFWorkbook(POIFSFileSystem fs, boolean preserveNodes) given a POI POIFSFileSystem object, read in its Workbook and populate the high and low level models.

我们用第一个构建器来生成一个Workbook

HSSFWorkbook
public HSSFWorkbook()

Creates new HSSFWorkbook from scratch (start here!)

使用方法如下：

HSSFWorkbook workbook = new HSSFWorkbook();

接下来再来对生成的Workbook进行保存操作，保存操作用「HSSFWorkbook」类的「write」方法。

write
public void write(java.io.OutputStream stream) throws java.io.IOException

Method write - write out this workbook to an Outputstream. Constructs
a new POI POIFSFileSystem, passes in the workbook binary representation
and writes it out. 
 
Parameters:
  stream - - the java OutputStream you wish to write the XLS to 
Throws: 
  java.io.IOException - if anything can't be written.

参数是作为保存对象的输出流对象「OutputStream」。

示例程序

可以自己实际做一下啊。

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 
public class POISample{
  public static void main(String[] args){
    HSSFWorkbook workbook = new HSSFWorkbook();
 
    FileOutputStream out = null;
    try{
      out = new FileOutputStream("sample.xls");
      workbook.write(out);
    }catch(IOException e){
      System.out.println(e.toString());
    }finally{
      try {
        out.close();
      }catch(IOException e){
        System.out.println(e.toString());
      }
    }
  }
}

运行刚才的示例程序来生成一个Excel文件吧。