Java工具类——将输出内容转换为表格形式

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFFont;
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.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;

import com.test.entity.Role;
import com.test.entity.User;

public class ExcelUtil {
	public static byte[] write2Excel(List users){
		byte[] data=null;
		ByteArrayOutputStream out=null;
		
		try {
			//创建excel2003
			Workbook wb=new HSSFWorkbook();
			out=new ByteArrayOutputStream();
			//创建新的sheet
			Sheet sheet=wb.createSheet("allUsers");
			
			//创建第一栏(表头信息)
			Row row=sheet.createRow(0);
			String[] titleArray={
					"登录名",
					"登录类型",
					"昵称",
					"密码",
					"用户类型",
					"头像",
					"积分",
					"锁",
					"注册日期",
					"年龄",
					"性别",
					"角色"
			};
			int columnCount=titleArray.length;
			for(int i=0;i0){
					String roleName="";
					for(Role role : user.getRoles()){
						roleName+=role.getName()+",";
					}
					row.createCell(11).setCellValue(roleName.substring(0,roleName.length()-1));
				
				}else{
					row.createCell(11).setCellValue("无角色");
				}
			}
			wb.write(out);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(out!=null){
				try {
					out.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		data=out.toByteArray();
		return data;
	}
}