Spring Boot + EasyExcel 導入導出，好用到爆，可以扔掉 POI 了！
EasyExcel
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EasyExcel是阿里巴巴開源poi插件之一，主要解決了poi框架使用復雜，sax解析模式不容易操作，數(shù)據(jù)量大起來容易OOM，解決了POI并發(fā)造成的報錯。主要解決方式：通過解壓文件的方式加載，一行一行的加載，并且拋棄樣式字體等不重要的數(shù)據(jù)，降低內(nèi)存的占用。
EasyExcel優(yōu)勢
注解式自定義操作。
輸入輸出簡單，提供輸入輸出過程的接口
支持一定程度的單元格合并等靈活化操作
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2
常用注解
@ExcelProperty 指定當前字段對應excel中的那一列?？梢愿鶕?jù)名字或者Index去匹配。當然也可以不寫，默認第一個字段就是index=0，以此類推。千萬注意，要么全部不寫，要么全部用index，要么全部用名字去匹配。千萬別三個混著用，除非你非常了解源代碼中三個混著用怎么去排序的。
@ExcelIgnore 默認所有字段都會和excel去匹配，加了這個注解會忽略該字段
@DateTimeFormat 日期轉(zhuǎn)換，用String去接收excel日期格式的數(shù)據(jù)會調(diào)用這個注解。里面的value參照java.text.SimpleDateFormat
@NumberFormat 數(shù)字轉(zhuǎn)換，用String去接收excel數(shù)字格式的數(shù)據(jù)會調(diào)用這個注解。里面的value參照java.text.DecimalFormat
@ExcelIgnoreUnannotated默認不加ExcelProperty 的注解的都會參與讀寫,加了不會參與
3
依賴
<dependency>
???<groupId>com.alibabagroupId>
???<artifactId>easyexcelartifactId>
???<version>2.1.4version>
dependency>
????
<dependency>
???<groupId>javax.servletgroupId>
???<artifactId>javax.servlet-apiartifactId>
???<version>4.0.1version>
???<scope>providedscope>
dependency>
<dependency>
???<groupId>com.alibabagroupId>
???<artifactId>fastjsonartifactId>
???<version>1.2.47version>
dependency>4
監(jiān)聽
/**
?* EasyExcel 導入監(jiān)聽
?*/
public?class?ExcelListener?extends?AnalysisEventListener {
????//可以通過實例獲取該值
????private?List<Object> datas =?new?ArrayList<Object>();
????@Override
????public?void?invoke(Object?o, AnalysisContext analysisContext) {
????????datas.add(o);//數(shù)據(jù)存儲到list，供批量處理，或后續(xù)自己業(yè)務邏輯處理。
????????doSomething(o);//根據(jù)自己業(yè)務做處理
????}
????private?void?doSomething(Object?object) {
????????//1、入庫調(diào)用接口
????}
????public?List<Object> getDatas() {
????????return?datas;
????}
????public?void?setDatas(List<Object> datas) {
????????this.datas = datas;
????}
????@Override
????public?void?doAfterAllAnalysed(AnalysisContext analysisContext) {
????????// datas.clear();//解析結(jié)束銷毀不用的資源
????}
}5
接口導入Excel
try?{
????//獲取文件名
????String filename = file.getOriginalFilename();
????//獲取文件流
????InputStream inputStream = file.getInputStream();
????//實例化實現(xiàn)了AnalysisEventListener接口的類
????ExcelListener listener =?new?ExcelListener();
????//傳入?yún)?shù)
????ExcelReader excelReader =?new?ExcelReader(inputStream, ExcelTypeEnum.XLS,?null, listener);
????//讀取信息
????excelReader.read(new?Sheet(1,?0, Test.class));
????//獲取數(shù)據(jù)
????List.size(); i++) {
????????????Testobj = (Test)?list.get(i);
????????????JSONObject jo =?new?JSONObject();
????????}
????}
}?catch?(Exception?e) {
????System.out.println(e.getMessage());
}6
接口導出Excel?
try?{
????String?filenames =?"111111";
????String?userAgent = request.getHeader("User-Agent");
????if?(userAgent.contains("MSIE") || userAgent.contains("Trident")) {
????????filenames = URLEncoder.encode(filenames,?"UTF-8");
????}?else?{
????????filenames =?new?String(filenames.getBytes("UTF-8"),?"ISO-8859-1");
????}
????response.setContentType("application/vnd.ms-exce");
????response.setCharacterEncoding("utf-8");
????response.addHeader("Content-Disposition",?"filename="?+ filenames +?".xlsx");
????EasyExcel.write(response.getOutputStream(), Test.class).sheet("sheet").doWrite(testList);
}?catch?(Exception e) {
}7
本地導入、本地導出
List testList =?new?ArrayList<>();
try?{
????String strUrl =?"C:\\Users\\Administrator\\Desktop\\json.xlsx";
????File multipartFile =?new?File(strUrl);
????InputStream inputStream =?new?FileInputStream(multipartFile);
????//實例化實現(xiàn)了AnalysisEventListener接口的類
????ExcelListener listener =?new?ExcelListener();
????//傳入?yún)?shù)
????ExcelReader excelReader =?new?ExcelReader(inputStream, ExcelTypeEnum.XLS,?null, listener);
????//讀取信息
????excelReader.read(new?Sheet(1,?0, Test.class));
????//獲取數(shù)據(jù)
????List .size(); i++) {
????????????Testobj = (Test)?list.get(i);
????????}
????}
}?catch?(Exception?e) {
????System.out.println(e.getMessage());
}
try?{
????String strUrl =?"C:\\Users\\Administrator\\Desktop\\json"+System.currentTimeMillis()+".xlsx";
????EasyExcel.write(strUrl,Test.class).sheet("sheet").doWrite(testList);
}?catch?(Exception?e) {
}以上就是EasyExcel的基礎使用過程，大家可以自己嘗試下。
來源：jianshu.com/p/4e6aa6342b33