性能优化建议ExcelUtils

[TomYule]

ExcelUtils中的方法
exportExcelNoModuleHandler
`private Workbook exportExcelNoModuleHandler(List<?> data, Class clazz, boolean isWriteHeader, String sheetName,
boolean isXSSF) throws Exception {

    Workbook workbook;
    if (isXSSF) {
        workbook = new XSSFWorkbook();
    } else {
        workbook = new HSSFWorkbook();
    }
    Sheet sheet;
    if (null != sheetName && !"".equals(sheetName)) {
        sheet = workbook.createSheet(sheetName);
    } else {
        sheet = workbook.createSheet();
    }
    Row row = sheet.createRow(0);
    List<ExcelHeader> headers = Utils.getHeaderList(clazz);
    if (isWriteHeader) {
        // 写标题
        for (int i = 0, length = headers.size(); i < length; i++) {
            row.createCell(i).setCellValue(headers.get(i).getTitle());
        }
    }
    // 写数据
    Object _data;
    for (int i = 0, length = data.size(); i < length; i++) {
        row = sheet.createRow(i + 1);
        _data = data.get(i);
        for (int j = 0,h = headers.size(); j < h; j++) {
            row.createCell(j).setCellValue(BeanUtils.getProperty(_data, headers.get(j).getFiled()));
        }
    }
    return workbook;
}`

尽量减少对变量的重复计算

明确一个概念，对方法的调用，即使方法中只有一句语句，也是有消耗的，包括创建栈帧、调用方法时保护现场、调用方法完毕时恢复现场等。所以例如下面的操作：

http://www.cnblogs.com/xrq730/p/4865416.html

[TomYule]

exportObjects2Excel方法优化
`
public void exportObjects2Excel(List<?> data, Class clazz, boolean isWriteHeader, String sheetName, boolean isXSSF, String targetPath){

    FileOutputStream fos = null;

    try{

        fos = new FileOutputStream(targetPath);

        exportExcelNoModuleHandler(data, clazz, isWriteHeader, sheetName, isXSSF).write(fos);

    } catch(Exception e){

        e.printStackTrace();

    } finally {

        try {

            fos.close();

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

`

[Crab2died]

恩，jdk1.7有对资源管理的更好办法