Java 使用反射和Poi将任意类导出为Excel

package com.zain.demo;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.log4j.Logger;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFCell;
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;

/**
*
* @author Zain
*
*/
public class ExcelUtilDemo {

public static final Logger log = Logger.getLogger(ExcelUtil.class);
public static String excelFileType;
public static String excelSavePath;
public static String excelSaveUrl;
static SimpleDateFormat sFormat = new SimpleDateFormat("yyyy-MM-dd");
public static final int COL_WIDTH = 13000;
public static final int ROW_HEIGHT = 5000;

/**
* 导出List对象到Excel文件
*
* @param name
*            文件名（不带后缀）
* @param data
*            数据（标题对象和list对象），（"listData" , list对象）（"titles" , 标题对象）
* @return URL和文件名
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public static List<String> objListToExcel(String name, Map data) {
Map<String, String> titles = (Map<String, String>) data.get("titles");
List listData = (List) data.get("listData");
List<String> result = new ArrayList<String>();
Object[] keys = titles.keySet().toArray();
String[] titleNames = new String[keys.length];
boolean setTitle = true;
for (int k = 0; k < keys.length; k++) {
String temp = keys[k].toString();
String[] subStr = StringUtil.split(temp, "-");
int index = Integer.valueOf(subStr[0]);
titleNames[index] = subStr[1];
}
try {
String path = excelSavePath + name + excelFileType;
FileUtil.createPath(excelSavePath);
File newFile = new File(path);
newFile.createNewFile();
XSSFWorkbook wb = new XSSFWorkbook();
XSSFSheet sheet = wb.createSheet();
// 创建绘图的顶层容器
Drawing drawing = sheet.createDrawingPatriarch();
CreationHelper helper = wb.getCreationHelper();
for (int i = 0; i <= listData.size(); i++) {
XSSFRow row = sheet.createRow(i);
Object obj = null;
if (i != 0) {
obj = listData.get(i - 1);
} else {
obj = listData.get(i);
}
for (int j = 0; j < titleNames.length; j++) {
XSSFCell cell = row.createCell(j);
if (setTitle) {
sheet.setColumnWidth(j, 6000);
cell.setCellValue(new XSSFRichTextString(titles.get(j
+ "-" + titleNames[j])));
} else {
String titleName = (String) titleNames[j];
titleName = titleName.replaceFirst(
titleName.substring(0, 1),
titleName.substring(0, 1).toUpperCase());
titleName = "get" + titleName;
Class clazz = Class.forName(obj.getClass().getName());
Method[] methods = clazz.getMethods();
Pattern pattern = Pattern.compile(titleName);
Matcher mat = null;
for (Method m : methods) {
mat = pattern.matcher(m.getName());
if (mat.find()) {
Object attr = m.invoke(obj, null);
if (attr != null) {
if (attr instanceof byte[]) {
int pictureIdx = wb.addPicture(
(byte[]) attr,
Workbook.PICTURE_TYPE_PNG);
ClientAnchor anchor = helper
.createClientAnchor();
anchor.setAnchorType(0);
// 设置图片显示位置
anchor.setRow1(i);
anchor.setCol1(j);
anchor.setDx1(getAnchorX(5,COL_WIDTH));
anchor.setDy1(getAnchorY(5,ROW_HEIGHT));

anchor.setRow2(i);
anchor.setCol2(j);
anchor.setDx2(getAnchorX(405,COL_WIDTH));
anchor.setDy2(getAnchorY(405,ROW_HEIGHT));
Picture picture = drawing
.createPicture(anchor,
pictureIdx);
picture.resize(0.5);
row.setHeight((short) getRowHeight(400));
sheet.setColumnWidth(j, (short) getColWidth(400));
} else {
cell.setCellValue(attr.toString());
}
} else {
cell.setCellValue("");
}
break;
}

}
}
}
setTitle = false;
}
OutputStream out = new FileOutputStream(path);
wb.write(out);
out.flush();
out.close();
result.add(excelSaveUrl);
result.add(name + excelFileType);
return result;
} catch (Exception e) {
log.error(MiscUtil.traceInfo(e));
return null;
}
}

/**
* 设置Excel标题
*
* @param name
*            导出类的全名
* @param exportAllColum
*            是否导出全部对应字段的列
* @param titles
*            自定义标题,与导出类的属性个数对应，为空时默认设置为属性名（"对应属性名-自定义名"）
* @return 标题对象
*/
@SuppressWarnings({ "rawtypes" })
public static Map<String, Object> setTitles(String name, String[] titles) {
Map<String, Object> title = new HashMap<String, Object>();
String[] newTitles;
Class clazz;
int index = 0;
try {
clazz = Class.forName(name);
Field[] fields = clazz.getDeclaredFields();
newTitles = new String[fields.length];
System.arraycopy(titles, 0, newTitles, 0, titles.length);
for (Field f : fields) {
if (!f.getName().equals("serialVersionUID")) {
if (newTitles[index] == null) {
newTitles[index] = f.getName();
}
title.put(index + "-" + f.getName(), titles[index]);
index++;
}
}
// System.out.println(title);
return title;
} catch (IndexOutOfBoundsException e) {
log.error(MiscUtil.traceInfo(e));
} catch (ClassNotFoundException e) {
log.error(MiscUtil.traceInfo(e));
} catch (Exception e) {
log.error(MiscUtil.traceInfo(e));
}
return title;
}

public static int getAnchorX(int px, int colWidth) {
return (int) Math.round(((double) 701 * 16000.0 / 301)
* ((double) 1 / colWidth) * px);
}

public static int getAnchorY(int px, int rowHeight) {
return (int) Math.round(((double) 144 * 8000 / 301)
* ((double) 1 / rowHeight) * px);
}

public static int getRowHeight(int px) {
return (int) Math.round(((double) 4480 / 300) * px);
}

public static int getColWidth(int px) {
return (int) Math.round(((double) 10971 / 300) * px);
}
}

Map titles = ExcelUtil.setTitles(Demo.class.getName(),
new String[] { "姓名", "性别"});//指定对象每个属性对应的列名
List<Demo> exportList = new ArrayList<Demo>();//需要导出的类数据集合
Map data = new HashMap();
data.put("titles", titles);
data.put("listData", exportList);
ExcelUtil.objListToExcel(
"测试导出类到Excel" , data));