Excel导出到文件工具

package com.jiechengkeji.manager.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Collection;
import java.util.UUID;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public abstract class ExcelBuilder<T> {

protected CellStyle titleStyle;

protected CellStyle contentStyle;

private int pointer =1;

private Workbook workbook ;

public ExcelBuilder(){
workbook= new XSSFWorkbook();
workbook.createSheet();
initStyle();

}

public ExcelBuilder<T> name(String sheetName){

workbook.setSheetName(0, sheetName);

return this;

}

public ExcelBuilder<T> title(String[] title){
Sheet sheet = workbook.getSheetAt(0);
Row row =sheet.createRow(0);
for(int i =0;i<title.length;i++){
Cell c = row.createCell(i,Cell.CELL_TYPE_STRING);
c.setCellValue(title[i]);
c.setCellStyle(titleStyle);

}

return this;
}

abstract protected String[] mapEntity(T t);

public ExcelBuilder<T> append(Collection<T> content){

Sheet sheet = workbook.getSheetAt(0);

for(T t: content){
Row row =sheet.createRow(pointer++);
String[] strs = this.mapEntity(t);
for(int i =0;i<strs.length;i++){
Cell c = row.createCell(i,Cell.CELL_TYPE_STRING);
c.setCellValue(strs[i]);
}
row.setRowStyle(contentStyle);

}
return this;
}

public File build(){
File file = new File(UUID.randomUUID().toString());
FileOutputStream fos =  null;
try {
file.createNewFile();
fos = new FileOutputStream(file);
workbook.write(fos);
} catch (FileNotFoundException e) {

e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
fos.flush();
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}

return file;
}

protected void initStyle() {
Font font = workbook.createFont();

font.setFontName("宋体");
font.setFontHeightInPoints((short) 14);// 设置字体大小

titleStyle=workbook.createCellStyle();
titleStyle.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
titleStyle.setFillForegroundColor(IndexedColors.GREEN.index);

//titleStyle.setFont(font);

contentStyle=workbook.createCellStyle();
//contentStyle.setFont(font);

}
}

public class ExcelBuilderTest extends BaseTest {

@Test
public void test() throws IOException {

List<User> users = ctx.getBean(IUserDao.class).getByPeriod(0, 100, DateConstants.ABSOLUTE_START,
DateConstants.ABSOLUTE_END);

ExcelBuilder<User> ueb = new ExcelBuilder<User>() {

@Override
protected String[] mapEntity(User user) {

return new String[] { Integer.toString(user.getId()), user.getUsername(), user.getCreateTime().toString() };
}

};

File excel = ueb.name("用户清单").title(new String[] { "ID", "姓名", "创建时间" })
.append(users)
.append(users)//可多次填充内容
.build();

}

}