JAVA实现数据库数据导入/导出到Excel（POI技术）

准备工作：

1.导入POI包：POI下载地址：http://download.csdn.net/detail/zxm1306192988/9522142（重要）

如下

2.导入导出到Excel工具类ExcelUtil.java，封装了POI对Excel的操作

package net.dqsy.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import javax.swing.JOptionPane;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFCellUtil;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.util.CellRangeAddress;

/**
* 描述：Excel写操作帮助类
*
*
* */
public class ExcelUtil {

/**
* 功能：创建HSSFSheet工作簿
* @param     wb    HSSFWorkbook
* @param     sheetName    String
* @return    HSSFSheet
*/
public static HSSFSheet createSheet(HSSFWorkbook wb,String sheetName){
HSSFSheet sheet=wb.createSheet(sheetName);
sheet.setDefaultColumnWidth(12);
sheet.setGridsPrinted(false);
sheet.setDisplayGridlines(false);
return sheet;
}

/**
* 功能：创建HSSFRow
* @param     sheet    HSSFSheet
* @param     rowNum    int
* @param     height    int
* @return    HSSFRow
*/
public static HSSFRow createRow(HSSFSheet sheet,int rowNum,int height){
HSSFRow row=sheet.createRow(rowNum);
row.setHeight((short)height);
return row;
}

public static HSSFCell createCell0(HSSFRow row,int cellNum){
HSSFCell cell=row.createCell(cellNum);
return cell;
}

/**
* 功能：创建CELL
* @param     row        HSSFRow
* @param     cellNum    int
* @param     style    HSSFStyle
* @return    HSSFCell
*/
public static HSSFCell createCell(HSSFRow row,int cellNum,CellStyle style){
HSSFCell cell=row.createCell(cellNum);
cell.setCellStyle(style);
return cell;
}

/**
* 功能：创建CellStyle样式
* @param     wb                HSSFWorkbook
* @param     backgroundColor    背景色
* @param     foregroundColor    前置色
* @param    font            字体
* @return    CellStyle
*/
public static CellStyle createCellStyle(HSSFWorkbook wb,short backgroundColor,short foregroundColor,short halign,Font font){
CellStyle cs=wb.createCellStyle();
cs.setAlignment(halign);
cs.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
cs.setFillBackgroundColor(backgroundColor);
cs.setFillForegroundColor(foregroundColor);
cs.setFillPattern(CellStyle.SOLID_FOREGROUND);
cs.setFont(font);
return cs;
}

/**
* 功能：创建带边框的CellStyle样式
* @param     wb                HSSFWorkbook
* @param     backgroundColor    背景色
* @param     foregroundColor    前置色
* @param    font            字体
* @return    CellStyle
*/
public static CellStyle createBorderCellStyle(HSSFWorkbook wb,short backgroundColor,short foregroundColor,short halign,Font font){
CellStyle cs=wb.createCellStyle();
cs.setAlignment(halign);
cs.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
cs.setFillBackgroundColor(backgroundColor);
cs.setFillForegroundColor(foregroundColor);
cs.setFillPattern(CellStyle.SOLID_FOREGROUND);
cs.setFont(font);
cs.setBorderLeft(CellStyle.BORDER_DASHED);
cs.setBorderRight(CellStyle.BORDER_DASHED);
cs.setBorderTop(CellStyle.BORDER_DASHED);
cs.setBorderBottom(CellStyle.BORDER_DASHED);
return cs;
}

/**
* 功能：多行多列导入到Excel并且设置标题栏格式
*/
public static void writeArrayToExcel(HSSFSheet sheet,int rows,int cells,Object [][]value){

Row row[]=new HSSFRow[rows];
Cell cell[]=new HSSFCell[cells];

for(int i=0;i<row.length;i++){
row[i]=sheet.createRow(i);

for(int j=0;j<cell.length;j++){
cell[j]=row[i].createCell(j);
cell[j].setCellValue(convertString(value[i][j]));

}

}
}

/**
* 功能：多行多列导入到Excel并且设置标题栏格式
*/
public static void writeArrayToExcel(HSSFWorkbook wb,HSSFSheet sheet,int rows,int cells,Object [][]value){

Row row[]=new HSSFRow[rows];
Cell cell[]=new HSSFCell[cells];

HSSFCellStyle ztStyle =  (HSSFCellStyle)wb.createCellStyle();

Font ztFont = wb.createFont();
ztFont.setBoldweight(Font.BOLDWEIGHT_BOLD);
//ztFont.setItalic(true);                     // 设置字体为斜体字
// ztFont.setColor(Font.COLOR_RED);            // 将字体设置为“红色”
ztFont.setFontHeightInPoints((short)10);    // 将字体大小设置为18px
ztFont.setFontName("华文行楷");             // 将“华文行楷”字体应用到当前单元格上
// ztFont.setUnderline(Font.U_DOUBLE);
ztStyle.setFont(ztFont);

for(int i=0;i<row.length;i++){
row[i]=sheet.createRow(i);

for(int j=0;j<cell.length;j++){
cell[j]=row[i].createCell(j);
cell[j].setCellValue(convertString(value[i][j]));

if(i==0)
cell[j].setCellStyle(ztStyle);

}

}
}

/**
* 功能：合并单元格
* @param     sheet        HSSFSheet
* @param     firstRow    int
* @param     lastRow        int
* @param     firstColumn    int
* @param     lastColumn    int
* @return    int            合并区域号码
*/
public static int mergeCell(HSSFSheet sheet,int firstRow,int lastRow,int firstColumn,int lastColumn){
return sheet.addMergedRegion(new CellRangeAddress(firstRow,lastRow,firstColumn,lastColumn));
}

/**
* 功能：创建字体
* @param     wb            HSSFWorkbook
* @param     boldweight    short
* @param     color        short
* @return    Font
*/
public static Font createFont(HSSFWorkbook wb,short boldweight,short color,short size){
Font font=wb.createFont();
font.setBoldweight(boldweight);
font.setColor(color);
font.setFontHeightInPoints(size);
return font;
}

/**
* 设置合并单元格的边框样式
* @param    sheet    HSSFSheet
* @param     ca        CellRangAddress
* @param     style    CellStyle
*/
public static void setRegionStyle(HSSFSheet sheet, CellRangeAddress ca,CellStyle style) {
for (int i = ca.getFirstRow(); i <= ca.getLastRow(); i++) {
HSSFRow row = HSSFCellUtil.getRow(i, sheet);
for (int j = ca.getFirstColumn(); j <= ca.getLastColumn(); j++) {
HSSFCell cell = HSSFCellUtil.getCell(row, j);
cell.setCellStyle(style);
}
}
}

/**
* 功能：将HSSFWorkbook写入Excel文件
* @param     wb        HSSFWorkbook
* @param     absPath    写入文件的相对路径
* @param     wbName    文件名
*/
public static void writeWorkbook(HSSFWorkbook wb,String fileName){
FileOutputStream fos=null;
File f=new File(fileName);
try {
fos=new FileOutputStream(f);
wb.write(fos);
int dialog = JOptionPane.showConfirmDialog(null,
f.getName()+"导出成功！是否打开？",
"温馨提示", JOptionPane.YES_NO_OPTION);
if (dialog == JOptionPane.YES_OPTION) {

Runtime.getRuntime().exec("cmd /c start \"\" \"" + fileName + "\"");
}

} catch (FileNotFoundException e) {
JOptionPane.showMessageDialog(null, "导入数据前请关闭工作表");

} catch ( Exception e) {
JOptionPane.showMessageDialog(null, "没有进行筛选");

} finally{
try {
if(fos!=null){
fos.close();
}
} catch (IOException e) {
}
}
}

public static String convertString(Object value) {
if (value == null) {
return "";
} else {
return value.toString();
}
}

}

3.导出Excel

JButton toExcelButton = new JButton("导出excel");
toExcelButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
File selectedFile = getSelectedFile(".xls");
if (selectedFile != null) {
String path = selectedFile.getPath();
// System.out.println(path);

HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("试卷");

String[] n = { "题干", "A", "B", "C", "D", "Answer" };

Object[][] value = new Object[questionInfos.size() + 1][6];

for (int m = 0; m < n.length; m++) {
value[0][m] = n[m];
}
for (int i = 0; i < questionInfos.size(); i++) {
value[i + 1][0] = questionInfos.get(i).getQuestion();
value[i + 1][1] = questionInfos.get(i).getA();
value[i + 1][2] = questionInfos.get(i).getB();
value[i + 1][3] = questionInfos.get(i).getC();
value[i + 1][4] = questionInfos.get(i).getD();
value[i + 1][5] = questionInfos.get(i).getAnswer();
}
ExcelUtil.writeArrayToExcel(wb, sheet, questionInfos.size() + 1, 6, value);

ExcelUtil.writeWorkbook(wb, path);
}
}
});

4.导入Excel

JButton fromExcelButton = new JButton("导入excel");
fromExcelButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
File selectedFile = getSelectedOpenFile(".xls");
if (selectedFile != null) {
String path = selectedFile.getPath();
String result = "success";
try {
// 创建对Excel工作簿文件的引用
HSSFWorkbook workbook = new HSSFWorkbook(new FileInputStream(
path));
// 创建对工作表的引用。
// HSSFSheet sheet = workbook.getSheet("Sheet1");
HSSFSheet sheet = workbook.getSheetAt(0);

int j = 1;//从第2行开始堵数据
// 第在excel中读取一条数据就将其插入到数据库中
while (j < sheet.getPhysicalNumberOfRows()) {
HSSFRow row = sheet.getRow(j);
QuestionInfo onequestioninfo = new QuestionInfo(null, null, null, null, null, null,GlobalInfo.selectedpaper);

for (int i = 0; i <= 5; i++) {
HSSFCell cell = row.getCell((short) i);

if (i == 0) {
onequestioninfo.setQuestion(cell.getStringCellValue());
} else if (i == 1){
onequestioninfo.setA(cell.getStringCellValue());
}
else if (i == 2){
onequestioninfo.setB(cell.getStringCellValue());
}
else if (i == 3){
onequestioninfo.setC(cell.getStringCellValue());
}
else if (i == 4){
onequestioninfo.setD(cell.getStringCellValue());
}
else if (i == 5){
onequestioninfo.setAnswer(cell.getStringCellValue());
}
}

j++;

jdbc.addQuestionInfo(onequestioninfo);
}

} catch (FileNotFoundException e2) {
// TODO Auto-generated catch block
System.out.println("notfound");
e2.printStackTrace();
} catch (IOException e3) {
// TODO Auto-generated catch block
System.out.println(e3.toString());

e3.printStackTrace();
}
}
}
});