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Java通過apache poi生成excel實(shí)例代碼

更新時(shí)間：2017年06月03日 16:22:55 作者：paulWen

本篇文章主要介紹了Java通過apache poi生成excel實(shí)例代碼，小編覺得挺不錯(cuò)的，現(xiàn)在分享給大家，也給大家做個(gè)參考。一起跟隨小編過來看看吧

首先,jar

maven 添加依賴

<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
<dependency>
 <groupId>org.apache.poi</groupId>
 <artifactId>poi-ooxml</artifactId>
 <version>3.15</version>
</dependency>

開始以為是poi，然后就直接加poi的依賴，誰知道并沒有所需要的類。查了查才發(fā)現(xiàn)是poi-ooxml

要用到的類

XSSFWorkbook ，代表一個(gè)excel文檔
XSSFSheet ，代表文檔中的一個(gè)sheet
XSSFRow ，代表sheet中的一行
XSSFCell ，代表row中的每一項(xiàng)的值

最最基本的使用

//創(chuàng)建excel文檔
XSSFWorkbook workbook = new XSSFWorkbook();
//創(chuàng)建sheet
XSSFSheet sheet = workbook.createSheet("sheetName");

int rownum=0;
//創(chuàng)建首行
XSSFRow firstrow = sheet.createRow(rownum++);
int cellnum = 0;
//把保存在titles中的各個(gè)列名，分別在row中創(chuàng)建cell
for(String key : titles){
 XSSFCell cell = firstrow.createCell(cellnum++);
 cell.setCellValue(key);
}


//下面可以繼續(xù)創(chuàng)建行

//把excel寫到要寫的outputStream中
workbook.write(output);
//最后關(guān)閉
workbook.close();

小例子一枚

利用反射，把bean類中各屬性（用getXxx取出），寫入到excel中

ExcelUtil.java

package me.paul.excelDemo;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;


public class ExcelUtil {
 
 public <T> void getExcel(List<T> list,Class<T> c,OutputStream output) throws IOException, IllegalAccessException, IllegalArgumentException, InvocationTargetException{
 Map<String,Method> methodMap = new LinkedHashMap<>(); 
 Method[] methods = c.getDeclaredMethods();
 for(int i=0;i<methods.length;i++){
  Method method = methods[i];
  String name = method.getName();
  Pattern pattern = Pattern.compile("get(.*)");
  Matcher matcher = null;
  if((matcher = pattern.matcher(name)).matches()){
  name = matcher.group(1);
  char ch = name.charAt(0);
  char newch = (char) (ch + 32); 
  name = name.replace(ch,newch);
  methodMap.put(name, method);
  }
 }
 
 XSSFWorkbook workbook = new XSSFWorkbook();
 XSSFSheet sheet = workbook.createSheet(c.getCanonicalName());
 int rownum=0;
 XSSFRow firstrow = sheet.createRow(rownum++);
 int cellnum = 0;
 for(String key : methodMap.keySet()){
  XSSFCell cell = firstrow.createCell(cellnum++);
  cell.setCellValue(key);
 }
 
 for(T t : list){
  XSSFRow row = sheet.createRow(rownum++);
  cellnum = 0;
  for(String key:methodMap.keySet()){
  Method method = methodMap.get(key);
                //設(shè)置可訪問，之前不知道這方法，所以關(guān)于反射那篇文章有錯(cuò)誤，見諒見諒
                method.setAccessible(true);
  Object obj = method.invoke(t);
  XSSFCell cell = row.createCell(cellnum++);
  cell.setCellValue(obj== null ? "":obj.toString());
  }
  
 }
 workbook.write(output);
 workbook.close();
 } 
}

App.java 進(jìn)行測(cè)試使用

package me.paul.excelDemo;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.List;

public class App {
 public static void main(String[] args) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException, IOException {
 List<User> list = new ArrayList<>();
 User u = new User();
 u.setId(1);
 u.setName("Paul");
 u.setAge(18);
 list.add(u);
 u = new User();
 u.setId(2);
 u.setName("Johnson");
 u.setAge(20);
 list.add(u);
 u = new User();
 u.setId(3);
 u.setName("David");
 u.setAge(22);
 list.add(u);
 OutputStream output = new FileOutputStream("/home/paul/user.xlsx");
 new ExcelUtil().getExcel(list, User.class,output);
 output.close();
 }
}

測(cè)試結(jié)果截圖