匯出樣式如下：

========================================================================================

工具類：

package com.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import com.entity.Student;

public class ExcelUtil1 {
  /**
    * 不按照實體類的欄位順序--水平排列
    * 這是一個通用的方法，利用了JAVA的反射機制，可以將放置在JAVA集合中並且符合一定條件的資料以  EXCEL 的形式輸出到指定IO裝置上
    * @param title         sheet名
    * @param headersName   表頭陣列
    * @param headersId     表頭所對應的欄位名稱(陣列)
    * @param dataset   需要顯示的資料集合,集合中一定要放置符合javabean風格的類的物件。此方法支援的 javabean屬性的資料型別有基本資料型別及String,Date,byte[](圖片資料)
    * @param out       與輸出裝置關聯的流物件，可以將EXCEL文件匯出到本地檔案或者網路中
    * @param pattern   如果有時間資料，設定輸出格式一般為"yyyy-MM-dd HH:mm:ss"
    * @param Excelpath   匯出Excel儲存的路徑和名稱 
    * 例如"C:"+File.separator+"Users"+File.separator+"Administrator"+File.separator+"Desktop"+File.separator+"學生表.xls"
    * 匯出到桌面，名稱為:學生表.xls  有時候要注意匯出檔案的名稱不要重複
    */
	public static<T> void exportExcelByHor(String title, String[] headersName,String[] headersId,
			Collection<T> dataset,OutputStream out, String pattern,String excelPath) {
		// 宣告一個工作薄
	    HSSFWorkbook wb = new HSSFWorkbook();
	    //宣告一個工作表(sheet表名稱)
	    HSSFSheet sheet = wb.createSheet(title);
	    //工作表列寬15位元組
	    sheet.setDefaultColumnWidth(20);
	    //建立單元格樣式
	    HSSFCellStyle style = wb.createCellStyle();
	    /*設定這些樣式*/
	    //style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);//設定前景色
	    //style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);//設定背景色
	    style.setBorderBottom(HSSFCellStyle.BORDER_THIN);//設定邊框
	    style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
	    style.setBorderRight(HSSFCellStyle.BORDER_THIN);
	    style.setBorderTop(HSSFCellStyle.BORDER_THIN);
	    style.setAlignment(HSSFCellStyle.ALIGN_CENTER);//左右居中  
	    style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);//上下居中
	    //生成一個字型
        HSSFFont font = wb.createFont();
        //font.setColor(HSSFColor.VIOLET.index);//顏色
        font.setFontHeightInPoints((short) 12);//字號
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);//加粗
        //把字型應用到當前的樣式
        style.setFont(font);
        //將其放入map
        Map<Integer,String> map = new HashMap<Integer,String>();
        for(int i=0;i<headersName.length;i++){
        	map.put(i, headersName[i]);
        }
	    /**
	     * 產生表格標題行(也就是第一行)行從0開始0-1-2-3
	     */
        HSSFRow row = sheet.createRow(0);
        Collection<String> c = map.values();
        Iterator<String> it = c.iterator();
        HSSFCell cell;
        int size = 0;
        while(it.hasNext()){
     	    cell = row.createCell(size);//建立單元格,並設定樣式
     	cell.setCellStyle(style);
     	cell.setCellValue(it.next());
     	size ++;
        }//建立好了第一行(每一列的名稱)
        //根據欄位寫入內容
        Iterator<T> dataIt = dataset.iterator();//資料
        int zdRow = 0;
        while(dataIt.hasNext()){//遍歷所有記錄
        	zdRow ++;
        	row = sheet.createRow(zdRow);//內容行從1開始
        	int zdCell = 0;//每一個單元格從0開始
        	T t = dataIt.next();//獲取每一條記錄
        	//利用反射,動態呼叫getXxx()方法得到屬性值(可以不按照原來欄位順序)
        	Field[] fields = t.getClass().getDeclaredFields();
        	for(int k=0;k<headersId.length;k++){//遍歷欄位
        		for(int i=0;i<fields.length;i++){//遍歷類中所有屬性
        			Field field = fields[i];
        			//getName()方法獲得的是屬性 ：id  name  sex
        			String fieldName = field.getName();
        			if(headersId[k].equals(fieldName)){
        				cell = row.createCell(zdCell);//建立每一行的單元格從0開始
             		    cell.setCellStyle(style);
             		    zdCell ++;
             		    String getMethodName = "get" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);//相當於getId getName getSex
             		    Class tCls = t.getClass();
             		    //使用反射呼叫一個方法  new Class[] {}:表示呼叫方法是傳遞的實際引數型別，若為字串則是String.class
						try {
							Method getMethod = tCls.getMethod(getMethodName,new Class[] {});
							//執行方法Object obj= method.invoke(物件, 引數1, 引數2...)
		     				Object value = getMethod.invoke(t, new Object[] {});
		     	            //判斷行方法後的返回值的型別後進行強制型別轉換
		     				HSSFRichTextString  textValue = null;
		     				if (value instanceof Integer) {//整數
		     	                int intValue = (Integer) value;
		     	                cell.setCellValue(intValue);
	     	                } else if (value instanceof Float) {//float小數
	     	                    float fValue = (Float) value;
	     	                    textValue = new HSSFRichTextString(String.valueOf(fValue));
	     	                    cell.setCellValue(textValue);
	     	                } else if (value instanceof Double) {//double小數
	     	                    double dValue = (Double) value;
	     	                    textValue = new HSSFRichTextString(String.valueOf(dValue));
	     	                    cell.setCellValue(textValue);
	     	                } else if (value instanceof Long) {//long型別
	     	                    long longValue = (Long) value;
	     	                    cell.setCellValue(longValue);
	     	                } else if (value instanceof Boolean) {//boolean
	     	                    boolean bValue = (Boolean) value;
	     	                    String sex = (bValue==true? "男":"女");
	     	                    cell.setCellValue(sex);
	     	                } else if (value instanceof Date) {//java.util.Date
	     	                    Date date = (Date) value;
	     	                    SimpleDateFormat sdf = new SimpleDateFormat(pattern);
	     	                    cell.setCellValue(sdf.format(date));
	     	                } else{//其它資料型別都當作字串簡單處理
	     	                    cell.setCellValue(value.toString());
	     	                }
		     				break;//找到匹配欄位後跳出迴圈
						} catch (NoSuchMethodException | SecurityException e) {
							e.printStackTrace();
						} catch (IllegalAccessException e) {
							e.printStackTrace();
						} catch (IllegalArgumentException e) {
							e.printStackTrace();
						} catch (InvocationTargetException e) {
							e.printStackTrace();
						}
             	    }
     	        }
     	    }
        }
        //迴圈完畢--預設匯出到桌面
        try {
        	out = new FileOutputStream(excelPath);
			wb.write(out);
			out.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} 
	}
	
	//測試
	public static void main(String[] args) {
		/*==============模擬資料=================*/
        List<Student> list = new ArrayList<Student>();
        list.add(new Student(111,"張三","男",22,"北京",4000.0,200.5,new Date()));
        list.add(new Student(222,"李四","男",23,"長沙",450.56,100.5,new Date()));
        list.add(new Student(333,"莉莉絲","女",24,"成都",8888.8,200.0,new Date()));
        list.add(new Student(444,"紅蓮","女",25,"上海",666.66,150.0,new Date()));
        list.add(new Student(555,"丹丹","女",26,"湖北",5000.50,200.0,new Date()));
        /*==============模擬資料=================*/
        String title = "2017名單";//匯出Excel表名
		//儲存路徑
		String path = "C:"+File.separator+"Users"+File.separator+"Administrator"+
				File.separator+"Desktop"+File.separator+"測試"+System.currentTimeMillis()+".xls";
		//匯出部分欄位且打亂欄位順序
		String[] headersName = {"年齡","性別","家庭住址","錄入時間","姓名"};//表頭的名字
		String[] headersId = {"age","sex","address","createTime","name"};//表頭對應的欄位名
		FileOutputStream out = null;//輸出流
		String pattern = "yyyy-MM-dd HH:mm:ss";
		exportExcelByHor(title, headersName, headersId, list, out, pattern, path);
	}
	
	
}
 

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實體類：學生

package com.entity;

import java.io.Serializable;
import java.util.Date;

public class Student implements Serializable {
	
	private Integer id;
    private String name;
    private String sex;
    private Integer age;
    private String address;
    private Double sal;
    private Double comm;
    private Date createTime;
    
    public Student(){}
    
	public Student(Integer id, String name, String sex, Integer age,
			String address, Double sal, Double comm, Date createTime) {
		super();
		this.id = id;
		this.name = name;
		this.sex = sex;
		this.age = age;
		this.address = address;
		this.sal = sal;
		this.comm = comm;
		this.createTime = createTime;
	}

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getSex() {
		return sex;
	}

	public void setSex(String sex) {
		this.sex = sex;
	}

	public Integer getAge() {
		return age;
	}

	public void setAge(Integer age) {
		this.age = age;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public Double getSal() {
		return sal;
	}

	public void setSal(Double sal) {
		this.sal = sal;
	}

	public Double getComm() {
		return comm;
	}

	public void setComm(Double comm) {
		this.comm = comm;
	}

	public Date getCreateTime() {
		return createTime;
	}

	public void setCreateTime(Date createTime) {
		this.createTime = createTime;
	}
}