POI实战-java开发excel详解之简单写出

1.4 POI简单写出Excel

代码部分：

 package com.vintage.testpoi;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;

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


 /**
  * POI入门 ：简单写出excel数据
  * @author VintageYu
  *
  */
 public class WriteExcelTest {

     public static void write(OutputStream outputStream) throws IOException{
         //初始一个workbook
         HSSFWorkbook workbook = new HSSFWorkbook();
         //创建一个表
         HSSFSheet sheet = workbook.createSheet("firstSheet");
         //创建行
         HSSFRow row = sheet.createRow(0);
         //创建单元格
         HSSFCell cell = row.createCell(0);
         cell.setCellValue(new HSSFRichTextString("hello POI"));
         workbook.write(outputStream);
     }

     public static void main(String[] args) {
         OutputStream outputStream = null;
         try {
             outputStream = new FileOutputStream(new File("E:\\helloPOI.xls"));
             write(outputStream);
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }finally{
             if(outputStream != null){
                 try {
                     outputStream.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
             }
         }
     }

 }

图4

 

以下贴近实际进一步修改：

从数据库中读出相关信息并写入到Excel中

数据库表如图：

图5

 主要类：
 package com.vintage.testpoi;

 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.List;

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


 /**
  * POI入门 ：简单写出excel数据
  * @author VintageYu
  *
  */
 public class WriteExcelTest {

     public static void write(OutputStream outputStream) throws IOException{
         //初始一个workbook
         HSSFWorkbook workbook = new HSSFWorkbook();
         List<Student> list = Conn.getData();
         //循环创建多个sheet
         for(int sheetIndex = 0; sheetIndex < 3; sheetIndex++){
             HSSFSheet sheet = workbook.createSheet("sheet"+sheetIndex);
             //创建多行
             for(int rowIndex = 0; rowIndex < list.size(); rowIndex++){
                 HSSFRow row = sheet.createRow(rowIndex);
                 Student student = list.get(rowIndex);
                 //创建多列
                 for(int cellnum = 0; cellnum < 4; cellnum++){
                     HSSFCell cell = row.createCell(cellnum);
                     switch (cellnum) {
                     case 0:
                         cell.setCellValue(student.getName());
                         break;
                     case 1:
                         cell.setCellValue(student.getNo());
                         break;
                     case 2:
                         cell.setCellValue(student.getNativePlace());
                         break;
                     case 3:
                         cell.setCellValue(student.getEdu());
                         break;
                     }
                 }
             }
         }
         workbook.write(outputStream);
     }

     public static void main(String[] args) {
         OutputStream outputStream = null;
         try {
             outputStream = new FileOutputStream(new File("E:\\helloPOI.xls"));
             write(outputStream);
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }finally{
             if(outputStream != null){
                 try {
                     outputStream.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
             }
         }

     }

 }

依赖类：

 public class Conn {

     public static Connection getConn(){
         Connection cn = null;
         try {
             Class.forName( "oracle.jdbc.driver.OracleDriver" );
             cn = DriverManager.getConnection( "jdbc:oracle:thin:@****:1521:***", "***", "***");
         } catch (ClassNotFoundException e) {
             e.printStackTrace();
         } catch (SQLException e) {
             e.printStackTrace();
         }
         return cn;
     }

     public static List<Student> getData(){
         List<Student> list = new ArrayList<Student>();
         Connection conn = getConn();
         String sql = "SELECT * FROM tpoi_vintage t";
         try {
             conn.setAutoCommit(false);
             PreparedStatement ps = conn.prepareStatement(sql);
             ResultSet rs = ps.executeQuery();
             while(rs.next()){
                 Integer id = rs.getInt("id");
                 String name = rs.getString("name");
                 String no = rs.getString("no");
                 String nativePlace = rs.getString("native");
                 String edu = rs.getString("edu");
                 Integer year = rs.getInt("YEAR");
                 Integer math = rs.getInt("MATH");
                 Integer chinese = rs.getInt("CHINESE");
                 Integer english = rs.getInt("ENGLISH");
                 Integer science = rs.getInt("SCIENCE");
                 Integer isCity = rs.getInt("ISCITY");
                 Date schoolDate = rs.getDate("SCHOOLDATE");
                 Date birth = rs.getDate("BIRTH");

                 Student student = new Student();
                 student.setId(id);
                 student.setName(name);
                 student.setNo(no);
                 student.setNativePlace(nativePlace);
                 student.setEdu(edu);
                 student.setYear(year);
                 student.setMath(math);
                 student.setChinese(chinese);
                 student.setEnglish(english);
                 student.setScience(science);
                 if(isCity == 0){
                     student.setCity(false);
                 }else if(isCity == 1){
                     student.setCity(true);
                 }
                 student.setSchoolDate(schoolDate);
                 student.setBirth(birth);

                 list.add(student);

             }
             conn.commit();
         } catch (SQLException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }

         return list;
     }

 public class Student {
     private Integer id;
     private String name;
     private String no;
     private String nativePlace;
     private String edu;
 以下省略。。。

写出Excel预览:

图6