java操作poi生成excel文件（.xlsx）

import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;


public class XlsDto2ExcelEx {
/**  
     *  
     * @param xls  
     *            XlsDto实体类的一个对象  
     * @throws Exception  
     *             在导入Excel的过程中抛出异常  
     */ 
    public static void xlsDto2Excel(List<User> xls) throws Exception {  
        // 获取总列数  
        int CountColumnNum = 5;  
        XSSFWorkbook hwb = new XSSFWorkbook();  
        XSSFCellStyle style = hwb.createCellStyle();


        style.setAlignment(XSSFCellStyle.ALIGN_CENTER);
        User user = null;  
        XSSFSheet sheet = hwb.createSheet();
        sheet.setColumnWidth(0,256*2*7);//一个汉字两个字符
        sheet.setColumnWidth(1,256*2*11);
        sheet.setColumnWidth(2,256*2*6);
        sheet.setColumnWidth(3,256*2*5);
        sheet.setColumnWidth(4,256*2*11);
        // sheet 对应一个工作页  
//        XSSFSheet sheet = hwb.createSheet("pldrxkxxmb"); 
        XSSFRow firstrow = sheet.createRow(0);
        XSSFCell[] firstcell = new XSSFCell[CountColumnNum];  
        String[] names = new String[CountColumnNum];  
        names[0] = "手机号";  
        names[1] = "身份证号";  
        names[2] = "资信平台";  
        names[3] = "击中规则";  
        names[4] = "时间";  
        for (int j = 0; j < CountColumnNum; j++) {  
            firstcell[j] = firstrow.createCell(j); 
            firstcell[j].setCellValue(new XSSFRichTextString(names[j]));;  
            firstcell[j].setCellStyle(style);
            
        }  
        for (int i = 0; i < xls.size(); i++) {  
            // 创建一行  
            XSSFRow row = sheet.createRow(i + 1);  
            // 得到要插入的每一条记录  
            user = xls.get(i);  
        XSSFCell xh0 = row.createCell(0);  
        xh0.setCellValue(user.getId()); 
        xh0.setCellStyle(style);
        XSSFCell xh1 = row.createCell(1);  
        xh1.setCellValue(user.getNo()); 
        xh1.setCellStyle(style);
        XSSFCell xh2 = row.createCell(2);  
        xh2.setCellValue(user.getPlatform());
        XSSFCell xh3 = row.createCell(3);  
        xh3.setCellValue(user.getRule()); 
        XSSFCell xh4 = row.createCell(4);  
        xh4.setCellValue(user.getTime()); 
        xh4.setCellStyle(style); 
            
        }  
        // 创建文件输出流，准备输出电子表格 
        //当HSSF类型的excel时，新建excel需要放在工程下POI2Excel的文件夹中。而为XSSF时，默认放在工程目录下。
        //HSSF版本的excel(2003)最大可存入65536条记录，而XSSF版本的excel则可存放1048576条记录
        OutputStream out = new FileOutputStream("user.xlsx");  
        hwb.write(out);  
        out.close();  
        System.out.println("数据库导出成功");  
    }  
    public static void main(String[] args){
    List<User> list = new ArrayList<User>();
    for(int i = 0; i< 1000; i++){
    list.add(new User("13512341204","441900196706299382", "同盾","D101", "2017-01-21 18:46:01"));    
    list.add(new User("15811111326","340303197703055389", "同盾","D101", "2017-01-21 18:47:00"));     
    list.add(new User("13512340067","653224197705141266", "同盾","D101", "2017-01-21 18:48:00"));     
    list.add(new User("15811111335","320900196710294535", "同盾","D101", "2017-01-21 18:49:00"));     
    list.add(new User("17700000424","510502199512057758", "同盾","D101", "2017-01-21 18:50:00"));    
    list.add(new User("14761508264","150701199107028299", "同盾","D101", "2017-01-21 18:51:00"));     
    list.add(new User("14760656721","632821198703038744", "聚立信","D101", "2017-01-21 18:52:00"));     
    list.add(new User("15845611122","421182198409244752", "同盾","D101", "2017-01-21 18:53:00"));     
    list.add(new User("13334557298","420704197711171695", "同盾","D101", "2017-01-21 18:55:00")); 
    }
    try {
xlsDto2Excel(list);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
   
    }
}
class User{
public User(String id,String no, String platform,String rule, String time){
this.id = id;
this.no = no;
this.platform = platform;
this.rule = rule;
this.time = time;
}
private String id;
private String no;
private String platform;
private String rule;
private String time;
public String getId() {
return id;
}


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


public String getNo() {
return no;
}


public void setNo(String no) {
this.no = no;
}


public String getPlatform() {
return platform;
}


public void setPlatform(String platform) {
this.platform = platform;
}


public String getRule() {
return rule;
}


public void setRule(String rule) {
this.rule = rule;
}


public String getTime() {
return time;
}


public void setTime(String time) {
this.time = time;
}

public String toString(){
return "id:" + this.id + ",no" + this.no + ",platform:" + this.platform + ",rule:" + this.rule + ", time:"+ this.time;
}
}