Flask接口签名sign原理与实例代码浅析
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2023-05-28
java实现把对象数组通过excel方式导出的功能
一、导入相关jar包,pom依赖如下:
二、开始撸代码
1.如果导出功能使用的比较多,可以将其做成一个工具类,对我下面贴出的代码进行改造
//结果返回的是写入的记录数(以下用的是自己业务场景数据)
public int downLoadToExcel(OutputStream outputStream,List
//文档对象
HSSFWorkbook wb = new HSSFWorkbook();
int rowNum = 0;
Sheet sheet = wb.createSheet("excel的标题");
Row row0 = sheet.createRow(rowNum++);
//因为场景不同,titil不同,可以在外面写成数组当参数传进来
row0.createCell(0).setCellValue("第一列属性名");
row0.createCell(1).setCellValue("第二列属性名");
row0.createCell(2).setCellValue("第三列属性名");
row0.createCell(3).setCellValue("第四列属性名");
row0.createCell(4).setCellValue("第五列属性名");
row0.createCell(5).setCellValue("第六列属性名");
if (paimaiMoneyVOList != null && paimaiMoneyVOList.size() > 0) {
for (PaimaiMoneyVO paimaiMoneyVO : paimaiMoneyVOList) {
Row row = sheet.createRow(rowNum++);
row.createCell(0).setCellValue(paimaiMoneyVO.getPaimaiId());
row.createCell(1).setCellValue(paimaiMoneyVO.getTitle());
row.createCell(2).setCellValue(paimaiMoneyVO.getUsername());
row.createCell(3).setCellValue(paimaiMoneyVO.getMoney()+"元");
row.createCell(4).setCellValue("升价拍");
row.createCell(5).setCellValue(bidder);
}
}
try {
wb.write(outputStream);
LogEnum.LAW_WARE.info("表数据写入到excel表成功,一共写入了"+(rowNum - 1)+"条数据");
outputStream.close();
} catch (IOException e) {
LogEnum.LAW_WARE.error("流关闭异常!", e);
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch (IOException e) {
LogEnum.LAW_WARE.error("流关闭异常!", e);
}
}
}
return rowNum - 1;
}
2.“工具类”写好后,下面就开始使用它了,从上面的函数参数可以看到,我们需要传过去两个对象,一个是输出流OutPutStream,通过流的方式把excel想要到浏览器,
另外一个就是我们需要导出的对象数组,好了,不解释太多,看代码。(下面的方法写在action层,通过struts.xml配置访问即可实现下载)
public void exportBail(){
this.fileName = "excel文件名";
try {
List
//下面是我的业务场景获取对象数组
if(paimaiMoneySearchParam!=null){
paimaiMoneySearchParam.setVendorId(WebHelper.getVenderId());
paimaiMoneySearchParam.setPageSize(Constants.AUCTION_WARE_PAGE_SIZE);
paimaiMoneySearchParam.setPage(page);
PaimaiMoneyDto paimaiMoneyDto = auctionWareService1.searchPopPaimaiMoneyList(paimaiMoneySearchParam);
if(paimaiMoneyDto!=null){
int count = paimaiMoneyDto.getCount();
int totalPage = count/ Constants.AUCTION_WARE_PAGE_SIZE + (count% Constants.AUCTION_WARE_PAGE_SIZE > 0?1:0);
for(int i=1;i<=totalPage;i++){
paimaiMoneySearchParam.setPage(i);
PaimaiMoneyDto paimaiMoneyResultResult = auctionWareService1.searchPopPaimaiMoneyList(paimaiMoneySearchParam);
if(paimaiMoneyResultResult!=null){
paimaiMoneyVOList.addAll(paimaiMoneyResultResult.getList());
}
}
}
}
OutputStream outputStream = response.getOutputStream();
response.reset();//清空输出流
//下面是对中文文件名的处理
response.setCharacterEncoding("UTF-8");//设置相应内容的编码格式
//解析浏览器
final String userAgent = request.getHeader("USER-AGENT").toLowerCase();
if(userAgent.contains("firefox")){ //火狐浏览器
fileName = new String(fileName.getBytes(), "ISO8859-1");
}else{
fileName = URLEncoder.encode(fileName, "UTF-8"); //其他浏览器
fileName = fileName.Replace("+", "%20"); //encode后替换,解决空格问题(其中%20是空格在UTF-8下的编码 ,如果不这么写,浏览器会用+代替空格)
}
response.setHeader("Content-Disposition", "attachment;filename=" +fileName + ".xls");//指定输出文件名
response.setContentType("application/msexcel");//定义输出类型
int rouNum = ensurePriceListToExcel(outputStream,paimaiMoneyVOList);
LogEnum.LAW_WARE.info("【RiseAuctionAction.downLoadEnsurePriceExcel】导出成功,一共更新了{"+rouNum+"}条记录");
} catch (Exception e) {
LogEnum.LAW_WARE.error("【RiseAuctionAction.downLoadEnsurePriceExcel】导出失败,error is {}", e);
}
}
三、拓展(详细的工具类开发)
如果你觉得上面写的太简单了,可以继续往下看,我把它整理出了“万能”的工具类,供大家参考。
package com.jd.pop.auction.util.excel;
import com.jd.common.web.result.Result;
import com.jd.pop.auction.util.excel.annotations.ExcelColumn;
import com.jd.pop.auction.util.excel.annotations.ExcelMapping;
import com.jd.pop.auction.util.excel.annotations.apt.ExcelColumnAPT;
import com.jd.pop.auction.util.excel.annotations.apt.ExcelMappingAPT;
import org.apache.log4j.Logger;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.util.CellRangeAddress;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
public class GenerateExcel {
private final static Logger LOG = Logger.gethttp://Logger(GenerateExcel.class);
private HSSFWorkbook workbook;
private HSSFCellStyle headStyle;
private HSSFFont headCellFont;
private HSSFCellStyle theadStyle;
private HSSFFont theadCellFont;
private HSSFCellStyle tbodyStyle;
private HSSFFont tbodyCellFont;
private HSSFFont stringFont;
private static final short COLUMN_WIDTH = 15;
private static final short ROW_HEIGHT = 400;
public GenerateExcel() {
this.workbook = new HSSFWorkbook();
//标题
this.headStyle = workbook.createCellStyle();
headStyle.setFillForegroundColor(HSSFColor.GREY_50_PERCENT.index);
headStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
// headStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
// headStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
// headStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
// headStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
headStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
// headStyle.setWrapText(true);
this.headCellFont = workbook.createFont();
headCellFont.setFontHeightInPoints((short)13);
headCellFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
headStyle.setFont(headCellFont);
this.theadStyle = workbook.createCellStyle();
theadStyle.setFillForegroundColor(HSSFColor.WHITE.index);
theadStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
theadStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
theadStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
theadStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
theadStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
theadStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
theadCellFont = workbook.createFont();
theadCellFont.setColor(HSSFColor.BLACK.index);
theadCellFont.setFontHeightInPoints((short) 12);
theadCellFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
theadStyle.setFont(theadCellFont);
tbodyStyle = workbook.createCellStyle();
tbodyStyle.setFillForegroundColor(HSSFColor.WHITE.index);
tbodyStyle.setFillPquATrSavattern(HSSFCellStyle.SOLID_FOREGROUND);
tbodyStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
tbodyStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
tbodyStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
tbodyStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
tbodyStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
tbodyStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
tbodyCellFont = workbook.createFont();
tbodyCellFont.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
tbodyStyle.setFont(tbodyCellFont);
stringFont = workbook.createFont();
stringFont.setColor(HSSFColor.BLACK.index);
}
public
Result result = new Result(false);
if(pager){
}else{
HSSFSheet sheet = workbook.createSheet( "第一页");
sheet.setDefaultColumnWidth(COLUMN_WIDTH);
sheet.setDefaultRowHeight(ROW_HEIGHT);
//标题
for (int i = 0; i HSSFRow titleRow = sheet.createRow(i); titleRow.setHeightInPoints(20f); sheet.addMergedRegion(new CellRangeAddress(i,i,0,fields.length-1)); HSSFCell titleCell =titleRow.createCell(0); titleCell.setCellValue(titles.get(i)); titleCell.setCellStyle(headStyle); } //列名 HSSFRow row = sheet.createRow(titles.size()); for (short i = 0; i < fields.length; i++) { HSSFCell cell = row.createCell(i); cell.setCellStyle(theadStyle); if(fields[i].isAnnotationPresent(ExcelColumn.class)){ ExcelColumn an_1 = fields[i].getAnnotation(ExcelColumn.class); HSSFRichTextString text = new HSSFRichTextString(an_1.name()); cell.setCellValue(text); }else if(fields[i].isAnnotationPresent(ExcelMapping.class)){ ExcelMapping an_1 = fields[i].getAnnotation(ExcelMapping.class); HSSFRichTextString text = new HSSFRichTextString(an_1.name()); cell.setCellValue(text); } } Iterator int index = titles.size(); while (it.hasNext()) { index++; row = sheet.createRow(index); T t = (T) it.next(); for (short i = 0; i < fields.length; i++) { HSSFCell cell = row.createCell(i); cell.setCellStyle(tbodyStyle); Field field = fields[i]; try { String textValue; if(field.isAnnotationPresent(ExcelMapping.class)){ textValue = new ExcelMappingAPT().getColumnValue(field,t,clazz); }else{ textValue = new ExcelColumnAPT().getColumnValue(field,t,clazz); } cell.setCellValue(textValue); } catch (NoSuchMethodException e) { String errorMsg = field.getName() +"字段,第"+ index+ "条数据, NoSuchMethodException 反射错误!"; LOG.error(errorMsg,e); result.addDefaultModel(errorMsg); return result; } catch (IllegalAccessException e) { String errorMsg = field.getName() +"字段,第"+ index+ "条数据, IllegalAccessException "; LOG.error(errorMsg,e); result.addDefaultModel(errorMsg); return result; } catch (InvocationTargetException e) { String errorMsg = field.getName() +"字段,第"+ index+ "条数据, InvocationTargetException "; LOG.error(errorMsg,e); result.addDefaultModel(errorMsg); return result; } } } } try { workbook.write(out); result.setSuccess(true); return result; } catch (IOException e) { String errorMsg = "将导出数据写入输出流失败!"; LOG.error("将导出数据写入输出流失败! ",e); result.addDefaultModel(errorMsg); return result; }finally { try { out.close(); } catch (IOException e) { String errorMsg = "关闭输出流异常!"; LOG.error("关闭输出流异常! ",e); result.addDefaultModel(errorMsg); return result; } } } } public class ExportExcelUtils { private final static Logger LOG = Logger.getLogger(ExportExcelUtils.class); public static Result result = new Result(false); if(CollectionUtils.isEmpty(sourceList)){ result.addDefaultModel("ExportExcelUtils's param sourceList is empty!"); LOG.error("ExportExcelUtils's param sourceList is empty!"); return result; } if( out == null){ LOG.error("ExportExcelUtils's param OutputStream is null!"); result.addDefaultModel("ExportExcelUtils's param OutputStream is null!"); return result; } Class clazz = null; Field[] fieldArr = null; try{ //得到需要转换的列名 clazz = sourceList.get(0).getClass(); Field[] fields = clazz.getDeclaredFields(); List for(Field field:Arrays.asList(fields)){ field.setAccessible(true); if(field.isAnnotationPresent(ExcelColumn.class)){ fieldList.add(field); }else if(field.isAnnotationPresent(ExcelMapping.class)){ fieldList.add(field); } } if(CollectionUtils.isEmpty(fieldList)){ LOG.error("实体类中无需要导出的字段!"); result.addDefaultModel("实体类中无需要导出的字段!"); return result; } fieldArr = fieldList.toArray(new Field[fieldList.size()]); }catch(Exception e){ LOG.error("数据拼装异常!"); result.addDefaultModel("数据拼装异常!"); return result; } //生成excel GenerateExcel ge = new GenerateExcel(); return ge.export(titles,fieldArr,clazz,sourceList,out,false); } } 这一部分写的比较粗糙,但是实现的比较详细,仅供参考,大家可以稍微改造成为自己独有的utils。
HSSFRow titleRow = sheet.createRow(i);
titleRow.setHeightInPoints(20f);
sheet.addMergedRegion(new CellRangeAddress(i,i,0,fields.length-1));
HSSFCell titleCell =titleRow.createCell(0);
titleCell.setCellValue(titles.get(i));
titleCell.setCellStyle(headStyle);
}
//列名
HSSFRow row = sheet.createRow(titles.size());
for (short i = 0; i < fields.length; i++) {
HSSFCell cell = row.createCell(i);
cell.setCellStyle(theadStyle);
if(fields[i].isAnnotationPresent(ExcelColumn.class)){
ExcelColumn an_1 = fields[i].getAnnotation(ExcelColumn.class);
HSSFRichTextString text = new HSSFRichTextString(an_1.name());
cell.setCellValue(text);
}else if(fields[i].isAnnotationPresent(ExcelMapping.class)){
ExcelMapping an_1 = fields[i].getAnnotation(ExcelMapping.class);
HSSFRichTextString text = new HSSFRichTextString(an_1.name());
cell.setCellValue(text);
}
}
Iterator
int index = titles.size();
while (it.hasNext()) {
index++;
row = sheet.createRow(index);
T t = (T) it.next();
for (short i = 0; i < fields.length; i++) {
HSSFCell cell = row.createCell(i);
cell.setCellStyle(tbodyStyle);
Field field = fields[i];
try {
String textValue;
if(field.isAnnotationPresent(ExcelMapping.class)){
textValue = new ExcelMappingAPT().getColumnValue(field,t,clazz);
}else{
textValue = new ExcelColumnAPT().getColumnValue(field,t,clazz);
}
cell.setCellValue(textValue);
} catch (NoSuchMethodException e) {
String errorMsg = field.getName() +"字段,第"+ index+ "条数据, NoSuchMethodException 反射错误!";
LOG.error(errorMsg,e);
result.addDefaultModel(errorMsg);
return result;
} catch (IllegalAccessException e) {
String errorMsg = field.getName() +"字段,第"+ index+ "条数据, IllegalAccessException ";
LOG.error(errorMsg,e);
result.addDefaultModel(errorMsg);
return result;
} catch (InvocationTargetException e) {
String errorMsg = field.getName() +"字段,第"+ index+ "条数据, InvocationTargetException ";
LOG.error(errorMsg,e);
result.addDefaultModel(errorMsg);
return result;
}
}
}
}
try {
workbook.write(out);
result.setSuccess(true);
return result;
} catch (IOException e) {
String errorMsg = "将导出数据写入输出流失败!";
LOG.error("将导出数据写入输出流失败! ",e);
result.addDefaultModel(errorMsg);
return result;
}finally {
try {
out.close();
} catch (IOException e) {
String errorMsg = "关闭输出流异常!";
LOG.error("关闭输出流异常! ",e);
result.addDefaultModel(errorMsg);
return result;
}
}
}
}
public class ExportExcelUtils {
private final static Logger LOG = Logger.getLogger(ExportExcelUtils.class);
public static
Result result = new Result(false);
if(CollectionUtils.isEmpty(sourceList)){
result.addDefaultModel("ExportExcelUtils's param sourceList is empty!");
LOG.error("ExportExcelUtils's param sourceList is empty!");
return result;
}
if( out == null){
LOG.error("ExportExcelUtils's param OutputStream is null!");
result.addDefaultModel("ExportExcelUtils's param OutputStream is null!");
return result;
}
Class clazz = null;
Field[] fieldArr = null;
try{
//得到需要转换的列名
clazz = sourceList.get(0).getClass();
Field[] fields = clazz.getDeclaredFields();
List
for(Field field:Arrays.asList(fields)){
field.setAccessible(true);
if(field.isAnnotationPresent(ExcelColumn.class)){
fieldList.add(field);
}else if(field.isAnnotationPresent(ExcelMapping.class)){
fieldList.add(field);
}
}
if(CollectionUtils.isEmpty(fieldList)){
LOG.error("实体类中无需要导出的字段!");
result.addDefaultModel("实体类中无需要导出的字段!");
return result;
}
fieldArr = fieldList.toArray(new Field[fieldList.size()]);
}catch(Exception e){
LOG.error("数据拼装异常!");
result.addDefaultModel("数据拼装异常!");
return result;
}
//生成excel
GenerateExcel ge = new GenerateExcel();
return ge.export(titles,fieldArr,clazz,sourceList,out,false);
}
}
这一部分写的比较粗糙,但是实现的比较详细,仅供参考,大家可以稍微改造成为自己独有的utils。
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