POI 导出Excel 封装

package test;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFFont;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

/**
 * 导出Excel 
 * 生成的文件格式是.xlsx 最低支持07版的Excel
 *
 */
public class ExportExcel {
	
	/** 表空间的名称 */
	private String sheetName;
	
	/** 文件路径 */
	private String filePath;
	
	/** Excel的首行名称 */
	private String[] title;
	
	/** 保存的数据 */
	private List<String[]> rows;
	
	/**
	 * 构造方法
	 * @param fileName 保存文件的名称
	 * @param rootPath 保存文件的路径
	 * @param sheetName 表空间的名称
	 * @param title Excel的首行名称
	 * @param rows 保存的数据
	 */
	public ExportExcel(String fileName, String rootPath, String sheetName, String[] title, List<String[]> rows) {
		this.sheetName = sheetName;
		this.title = title;
		this.rows = rows;
		StringBuffer sb = new StringBuffer();
		sb.append(rootPath).append(File.separator).append(fileName).append(".xlsx");
		this.filePath = sb.toString();
	}
	
	/**
	 * 导出数据
	 */
	public void export(){
		XSSFWorkbook wb = new XSSFWorkbook();
		XSSFSheet sheet = wb.createSheet(sheetName);//创建工作表
		writeRowValue(wb,sheet,1);
	}
	
	/**
	 * 追加行
	 */
	public void addRows(){
		if(exists()){
			XSSFWorkbook wb = null;
			try {
				wb = new XSSFWorkbook((new BufferedInputStream (new FileInputStream(filePath))));
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
			if(isSheetExists(wb)){
				XSSFSheet sheet = wb.getSheet(sheetName);
		    	int rowSum = sheet.getLastRowNum();//当前有多少行
		    	writeRowValue(wb,sheet,rowSum+1);
			}
		}
		
	}
	
	/**
	 * 添加sheet
	 */
	public void addSheet(){
		if(exists()){
			XSSFWorkbook wb = null;
			try {
				wb = new XSSFWorkbook((new BufferedInputStream (new FileInputStream(filePath))));
			} catch (FileNotFoundException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
			XSSFSheet sheet = wb.createSheet(sheetName);//创建工作表
			writeRowValue(wb,sheet,1);
		}
		
	}
	
	/**
	 * 
	 * @param sheet
	 * @param rowIndex 从第几行开始写入数据
	 */
	private void writeRowValue(XSSFWorkbook wb, XSSFSheet sheet, int rowIndex){
	    XSSFCellStyle style = getStyle(wb);//列数据单元格样式
    	    int columnNum = title.length;//定义所需要的列数
    	    if(1 == rowIndex){
    		XSSFCellStyle columnToStyle = getColumnTopStyle(wb);//列头单元格样式
        	XSSFRow heard = sheet.createRow(0); //创建第一行
        	heard.setHeightInPoints(20);//设置行高
        	for(int n=0; n<columnNum; n++){
        		sheet.setColumnWidth(n, 24*255);
        		XSSFCell cell = heard.createCell(n);
        		cell.setCellValue(title[n]);
        		cell.setCellStyle(columnToStyle);
        	}
    	   }
    	
    	   int rowSize = rows.size();
    	   for(int i=0; i<rowSize;i++){
    		XSSFRow row = sheet.createRow(i + rowIndex);
    		row.setHeightInPoints(20);
    		String[] rowValue = rows.get(i);
    		for(int n=0; n<columnNum; n++){
    			XSSFCell cell = row.createCell(n);
        		cell.setCellValue(rowValue[n]);
        		cell.setCellStyle(style);
    		}
    	   }
    	   File file = new File(filePath);
    	   try {
			FileOutputStream fos = new FileOutputStream(file);
			wb.write(fos);
			fos.flush();
			fos.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
　　/**
     * 判断sheet是否存在 
     * 如果该sheet存在的话返回true
     * 不存在的话返回false
     * @param sheetName
     * @param wb
     * @return
     */
    private boolean isSheetExists(XSSFWorkbook wb){
 	   if(wb.getSheetIndex(sheetName) == -1){
 		  return false; 
 	   }
 	   return true;
    }
	
    /**
     * 判断该文件是否存在
     * 如果存在返回true  
     * @return
     */
    private boolean exists(){
    	File file = new File(filePath);
    	if(file.exists()){//该文件如果已存在，则不作操作;
    		return true;
    	}
    	return false;
    }
	
   /**
    * 列头单元格样式 
    * @param wb
    * @return
    */
    private XSSFCellStyle getColumnTopStyle(XSSFWorkbook wb){
    	XSSFFont font = wb.createFont();
        font.setFontHeightInPoints((short)11);  //设置字体大小  
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);  //字体加粗  
        font.setFontName("Courier New");   //设置字体名字   
    	
    	XSSFCellStyle style = wb.createCellStyle();
    	style.setFont(font); //应用字体
        style.setWrapText(false);  //设置自动换行
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);  //设置水平对齐的样式为居中对齐
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);  //设置垂直对齐的样式为居中对齐
        return style;  
    }
    
    /**
     * 列数据信息单元格样式 
     * @param wb
     * @return
     */
    private XSSFCellStyle getStyle(XSSFWorkbook wb){
    	XSSFFont font = wb.createFont();
        font.setFontHeightInPoints((short)11);  //设置字体大小  
        font.setFontName("Courier New");   //设置字体名字   
    	
    	XSSFCellStyle style = wb.createCellStyle();
    	style.setFont(font); //应用字体
    	style.setWrapText(true);  
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);  //设置水平对齐的样式为居中对齐
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);  //设置垂直对齐的样式为居中对齐
        return style;  
    }
	
	
}

XSSFCellStyle style = wb.createCellStyle();
style.setFillForegroundColor(new XSSFColor(new java.awt.Color(255, 255, 153)));

XSSFFont font = wb.createFont();
font.setColor(new XSSFColor(new java.awt.Color(0, 112, 192)));

sheet.groupRow(i, j);
sheet.setRowSumsBelow(false);
sheet.setRowSumsRight(false);