java 利用 poi 生成 Excel文件的例子

package com.yihaomen.poi.sample;

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

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;
import org.apache.poi.xssf.usermodel.XSSFSheet;


/**
* Excel util, create excel sheet, cell and style.
* @param <T> generic class.
*/
public class ExcelUtil<T> {
   
    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<T> 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(T 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.substring(0,1).toUpperCase() + fieldName.substring(1);                   
                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;        
    }

}

package com.yihaomen.poi.test;

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;

import com.yihaomen.poi.sample.ExcelUtil;
import com.yihaomen.poi.sample.User;

public class PoiTest {
    
     /*excel column formate:column_#_width, excel中每列的名称*/
    public static final String[] RECORES_COLUMNS = new String[]{
            "User Name_#_3000",
            "Address_#_7000"           
            };
    /*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[]{
        "name","address"
    };
    
    public static void main(String[] args) throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, IOException {
        List<User> users = new ArrayList<User>();
        for(int i=0; i<10;i++){
            User u = new User();
            u.setAddress("address :" + i);
            u.setName("name: "+ i);
            u.setAge(i);
            users.add(u);
        }
        
        //实际项目中，这个list 估计是从http://www.wfuyu.com/db/中得到的
        
        HSSFWorkbook workbook = new HSSFWorkbook();
        ExcelUtil<User> userSheet = new ExcelUtil<User>();
        userSheet.creatAuditSheet(workbook, "user sheet xls", 
                users, RECORES_COLUMNS, RECORES_FIELDS);
        
        FileOutputStream fileOut = new FileOutputStream("D:/test.xls"); 
        workbook.write(fileOut); 
        fileOut.close(); 
    }

}

package com.yihaomen.poi.sample;

public class User {
    
    private String name;
    private int age;
    private String address;
    
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
}

sheet.protectSheet(""); // 设置了1个空的密码

char[] endChar = Character.toChars( 'A' + (headerColumns.length - 1) );        
String rangeAddress = "A1:" + String.valueOf(endChar) + "1";
sheet.setAutoFilter(CellRangeAddress.valueOf(rangeAddress));