java+jxls利用excel模版进行导出

　　大多时候会出现需要导出excel的功能，利用poi可以实现简单的导出，可以说poi的功能非常强大可以做到细节的定制化操作，但相对于在office操作excel，利用poi完全生成excel会显得非常复杂，细节代码会特别多。在这个时候我们可以事先利用offfice制定好一个模版文件，在利用jxls来通过模版文件来实现复杂excel的导出。

　　模版的制作和一般excel的编写是一样的，在需要填充的网格利用{}来进行取出java中传进来的变量值，如图：

在java中：

InputStream is =getFileInputStream(templateFileName);//获取模板输入流
XLSTransformer transformer = new XLSTransformer();
HSSFWorkbook resultWorkbook =transformer.transformMultipleSheetsList(is,prints/*要打印的list*/, 
sheetNames/*sheet的名称list*/, "print"/*excel的bean名称*/, new HashMap(), 0);

　　在excel中，jxls会将要打印的list通过我们定义的bean名称取出进行遍历，在源码中

public HSSFWorkbook transformMultipleSheetsList(InputStream is, List objects, List newSheetNames, String beanName, Map beanParams, int startSheetNum) throws ParsePropertyException {
        HSSFWorkbook hssfWorkbook = null;

        try {
            if (beanParams != null && ((Map)beanParams).containsKey(beanName)) {
                throw new IllegalArgumentException("Selected bean name '" + beanName + "' already exists in the bean map");
            }

            if (beanName == null) {
                throw new IllegalArgumentException("Bean name must not be null");
            }

            if (beanParams == null) {
                beanParams = new HashMap();
            }

            POIFSFileSystem fs = new POIFSFileSystem(is);
            hssfWorkbook = new HSSFWorkbook(fs);

            for(int sheetNo = 0; sheetNo < hssfWorkbook.getNumberOfSheets(); ++sheetNo) {
                String spreadsheetName = hssfWorkbook.getSheetName(sheetNo);
                if (!this.isSpreadsheetToRemove(spreadsheetName)) {
                    if (this.isSpreadsheetToRename(spreadsheetName)) {
                        hssfWorkbook.setSheetName(sheetNo, this.getSpreadsheetToReName(spreadsheetName));
                    }

                    HSSFSheet hssfSheet = hssfWorkbook.getSheetAt(sheetNo);
                    if (startSheetNum == sheetNo && objects != null && !objects.isEmpty()) {
                        for(int i = 0; i < objects.size(); ++i) {
                            Object bean = objects.get(i);
                            String beanKey = beanName;
                            if (i != 0) {
                                beanKey = beanName + i;
                                HSSFSheet newSheet = hssfWorkbook.createSheet((String)newSheetNames.get(i));
                                Util.copySheets(newSheet, hssfSheet, beanName, beanKey);
                                Util.copyPageSetup(newSheet, hssfSheet);
                                Util.copyPrintSetup(newSheet, hssfSheet);
                            } else {
                                hssfWorkbook.setSheetName(sheetNo, (String)newSheetNames.get(i));
                            }

                            ((Map)beanParams).put(beanKey, bean);//在此次将我们传入的list通过map的形式放入beanParams
                        }
                    }
                } else {
                    hssfWorkbook.removeSheetAt(sheetNo);
                    --sheetNo;
                }
            }
        } catch (IOException var16) {
            var16.printStackTrace();
        }

        if (hssfWorkbook != null) {
            for(int i = 0; i < hssfWorkbook.getNumberOfSheets(); ++i) {
                Util.setPrintArea(hssfWorkbook, i);
            }
        }

        this.transformWorkbook(hssfWorkbook, (Map)beanParams);//通过模板和beanParams生产excel
        return hssfWorkbook;
    }

View Code

在excel中通过beanParams的Map形式来进行取值，有点类似于freemarker语法，但不同于freemarker

在此事例中，我定义了一个类（domain）来存放list，类的形式如下（即要打印的list的元素是以下类）

public class ExcelPrintDomain implements Serializable {
    private List lista = new ArrayList();
    private Object domaina;
  
    private ServletContext context;
    private int pageNo;
   

    public ExcelPrintDomain() {
    }

    public ExcelPrintDomain(ServletContext context) {
        this.context = context;
    }

    public void addDomain(Object obj) {
        this.domains.add(obj);
    }

    public void addLista(Object obj) {
        this.lista.add(obj);
    }

    public int getPageNo() {
        return this.pageNo;
    }

    public void setPageNo(int pageNo) {
        this.pageNo = pageNo;
    }

    public List getLista() {
        return this.lista;
    }

    public void setLista(List lista) {
        this.lista = lista;
    }

    public Object getDomaina() {
        return this.domaina;
    }

    public void setDomaina(Object domaina) {
        this.domaina = domaina;
    }
}