Java 使用POI导出Excel文件

导出为Excel文件，所需要引入的包与导入Excel相同，如下（可能有些不太必要）：



demo的详细代码如下：

import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class ExcelExportTest {

/*excel column formate:column_#_width, excel中每一列的名称*/
public static final String[] RECORES_COLUMNS = new String[]{
"UserNumber_#_5000",
"ExtensionName_#_5000",
"PositionIndex_#_5000"
};

private static final String ORIGINAL_NUM = "1000";
/*the column will display on xls files. must the same as the entity fields.对应上面的字段.*/
public static final String[] RECORES_FIELDS = new String[]{
"Userno","Extname","Posindex"
};

public static void main(String[] args) throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, IOException {
List<UserData> users = new ArrayList<UserData>();
for(int i=0; i<10;i++){
UserData u = new UserData();
u.setUserno(ORIGINAL_NUM+i);
u.setExtname(ORIGINAL_NUM+i);
u.setPosindex(String.valueOf(i));
users.add(u);
}
//实际项目中，这个list 估计是从数据库中得到的
HSSFWorkbook workbook = new HSSFWorkbook();
ExcelUtil<UserData> userSheet = new ExcelUtil<UserData>();
for(int j = 0;j<3;j++){
userSheet.creatAuditSheet(workbook, "sheet"+(j+1),
users, RECORES_COLUMNS, RECORES_FIELDS);
}

FileOutputStream fileOut = new FileOutputStream("D:/test1.xls");
workbook.write(fileOut);
fileOut.flush();
fileOut.close();
}
}

ExcelUtil类如下：

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;

public class ExcelUtil <UserData>{
public HSSFCellStyle getCellStyle(HSSFWorkbook workbook,boolean isHeader){
HSSFCellStyle style = workbook.createCellStyle();
style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
style.setBorderRight(HSSFCellStyle.BORDER_THIN);
style.setBorderTop(HSSFCellStyle.BORDER_THIN);
style.setLocked(true);
if (isHeader) {
style.setFillForegroundColor(HSSFColor.GREY_25_PERCENT.index);
style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
HSSFFont font = workbook.createFont();
font.setColor(HSSFColor.BLACK.index);
font.setFontHeightInPoints((short) 12);
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
style.setFont(font);
}
return style;
}
public void generateHeader(HSSFWorkbook workbook,HSSFSheet sheet,String[] headerColumns){
HSSFCellStyle style = getCellStyle(workbook,true);
Row row = sheet.createRow(0);
row.setHeightInPoints(30);
for(int i=0;i<headerColumns.length;i++){
Cell cell = row.createCell(i);
String[] column = headerColumns[i].split("_#_");
sheet.setColumnWidth(i, Integer.valueOf(column[1]));
cell.setCellValue(column[0]);
cell.setCellStyle(style);
}
}

@SuppressWarnings({ "rawtypes", "unchecked" })
public HSSFSheet creatAuditSheet(HSSFWorkbook workbook,String sheetName,
List<UserData> dataset,String[] headerColumns,String[] fieldColumns) throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {

HSSFSheet sheet = workbook.createSheet(sheetName);
//	sheet.protectSheet("1234");//设置Excel保护密码

generateHeader(workbook,sheet,headerColumns);
HSSFCellStyle style = getCellStyle(workbook,false);
SimpleDateFormat sd = new SimpleDateFormat("yyyy-MM-dd");
int rowNum = 0;
for(UserData t:dataset){
rowNum++ ;
Row row = sheet.createRow(rowNum);
row.setHeightInPoints(25);
for(int i = 0; i < fieldColumns.length; i++){
String fieldName = fieldColumns[i] ;
String getMethodName = "get" + fieldName;
try {
Class clazz = t.getClass();
Method getMethod;
getMethod = clazz.getMethod(getMethodName, new Class[]{} );
Object value = getMethod.invoke(t, new Object[]{});
String cellValue = "";
if (value instanceof Date){
Date date = (Date)value;
cellValue = sd.format(date);
}else{
cellValue = null != value ? value.toString() : "";
}
Cell cell = row.createCell(i);
cell.setCellStyle(style);
cell.setCellValue(cellValue);
} catch (Exception e) {

}
}
}
return sheet;
}

}

UserData类

public class UserData {

private String userno;

private String extname;

private String posindex;

public String getUserno() {
return userno;
}

public void setUserno(String userno) {
this.userno = userno;
}

public String getExtname() {
return extname;
}

public void setExtname(String extname) {
this.extname = extname;
}

public String getPosindex() {
return posindex;
}

public void setPosindex(String posindex) {
this.posindex = posindex;
}

}
以上代码是简单导出Excel的demo，应该都能看得懂，这里不再详细解释，有问题留言。