报表导出功能实现

          近期做的项目中涉及到报表导出的功能，在这里进行小小总结一下，希望能帮助到到家。

          首先实现报表导出到指定文件下，以excel格式报表为例进行说吧。

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import java.net.URLEncoder;

import java.util.Date;

import java.util.List;

import java.util.Map;

import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import jxl.Workbook;
import jxl.format.BorderLineStyle;
import jxl.write.DateFormat;
import jxl.write.DateTime;
import jxl.write.Label;
import jxl.write.WritableCellFormat;
import jxl.write.WritableFont;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
import jxl.write.WriteException;
import jxl.write.biff.RowsExceededException;


public class CreateSalaryExcel {

 private OutputStream os = null;//写工作流用于在指定位置生成文件
    private WritableWorkbook wwb = null;//新建一个工作表
    
    private WritableSheet wb = null;//sheet
    
    private int no = 3;//数据加载的起始行

 public String createExcel(){

String path = f:\test.xls;

try {
   os = new FileOutputStream(path);//生成空的表格
wwb = Workbook.createWorkbook(os);//新建工作薄
wb = wwb.createSheet(fileName, 0);//设定工作薄名称
try {
wb.mergeCells(0, 0, 9, 0);//合并第一列第一行到第9列第一行的所有单元格 
} catch (RowsExceededException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
               /**
                * 表中要用到的样式
                */
//主标题字体样式
WritableFont font1 = new WritableFont(WritableFont.ARIAL,24,WritableFont.BOLD); //设定字体样式
WritableCellFormat format1 = new WritableCellFormat(font1);//样式添加到

try {
format1.setAlignment(jxl.format.Alignment.CENTRE);//居中
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Label label1 = new Label(0, 0, date+fileName, format1);//添加lable对象
try {
wb.addCell(label1);
} catch (RowsExceededException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("副标题样式");
//副标题样式
WritableFont font2 = new WritableFont(WritableFont.ARIAL, 16,WritableFont.BOLD);//设定字体样式
WritableCellFormat format2 = new WritableCellFormat(font2);//样式加载到
try {
format2.setAlignment(jxl.format.Alignment.CENTRE);//居中
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 
try {
wb.mergeCells(0, 1, 1, 1);//合并单元格 第一个参数为第几行，第二个参数为那到列开始合并，第三个参数为到那一列结束，第四个参数为合并几行
} catch (RowsExceededException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Label label2 = new Label(0,1, "报表生成时间：", format2);
try {
wb.addCell(label2);
} catch (RowsExceededException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 
 
// 日期样式
DateFormat df = new DateFormat("yyyy-MM-dd");
WritableCellFormat wcfdF = new WritableCellFormat(df);
try {
wcfdF.setAlignment(jxl.format.Alignment.LEFT);
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 
try {
wb.mergeCells(2, 1, 3, 1);
} catch (RowsExceededException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 
DateTime label3 = new DateTime(2, 1, new Date(), wcfdF);//所有时间参数用jxl.write
try {
wb.addCell(label3);
} catch (RowsExceededException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 
//标题样式
System.out.println("标题样式");
WritableFont font3  = new WritableFont(WritableFont.TIMES,10,WritableFont.BOLD);
WritableCellFormat format3 = new WritableCellFormat(font3);
 
try {
format3.setAlignment(jxl.format.Alignment.CENTRE);
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
format3.setBorder(jxl.format.Border.ALL, BorderLineStyle.THIN);//border要用：jxl.format.Border;
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
 
try {
format3.setWrap(true);
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("标题内容");

//表格头部

Label label4 = new Label(0, 2, "时间", format3);
wb.addCell(label4);

 
label4 = new Label(1, 2,"ip", format3);
wb.addCell(label4);
 
label4 = new Label(2, 2,文件名", format3);
wb.addCell(label4);
 
label4 = new Label(3, 2,"MD5值", format3);
wb.addCell(label4);
 
label4 = new Label(4, 2,"存放路径", format3);
wb.addCell(label4);
 
//内容字体样式
System.out.println("内容字体样式");
WritableFont font4 = new WritableFont(WritableFont.TIMES, 9, WritableFont.NO_BOLD);
 
WritableCellFormat format4 = new WritableCellFormat(font4);
format4.setAlignment(jxl.format.Alignment.CENTRE);
 
//添加数据
System.out.println("添加数据");

 //这里对要导出的数据进行遍历，填入对应的位置

                       for (Map<String, String> map : list) {
Label one = new Label(0, no, map.get("time"), format4);
wb.addCell(one); 
System.out.println(map.get("filePath"));

Label tow  = new Label(1, no, map.get("guid"), format4);
wb.addCell(tow);
 
Label three = new Label(2, no, map.get("fileName"), format4);
System.out.println( map.get("fileName"));
wb.addCell(three);
 
Label four = new Label(3, no, map.get("MD5"), format4);
wb.addCell(four);
 
Label five = new Label(4, no, map.get("filePath"), format4);
wb.addCell(five);

                                     

}

              wwb.write();//把数据写入表中
     return path;

 } catch (IOException e) {
       // TODO Auto-generated catch block
       e.printStackTrace();
      } catch (RowsExceededException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (WriteException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{

try {
//关闭操作对像
   wwb.close();
   os.close();
  } catch (WriteException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }


}
//           }else{
//    
//     path = "no";
//     } 
    try {
downloadExcel(null, null, path);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
     return path;
    }


    protected void downloadExcel(HSSFWorkbook workbook, HttpServletResponse response, String filename) throws IOException {
        OutputStream out = response.getOutputStream();


    response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));
    response.setContentType("application/msexcel;charset=UTF-8");
    workbook.write(out);
        
    out.close();        
}

}

这样就把数据导出到了指定的位置了，但是实际开发中并不能让报表导出到指定位置去，是用户选择存档的，所以以上这种方式不正确，下来对以上方式进行一个小小的改动就ok了。

上面的方法不是返回了个path吗，咱就从这下手，我的思路是先把文件存放到服务器上的指定位置上去，然后利用struts的下载功能找到该路径下载该文件，下载完后删不删就是你的事了，自己看着办。

//这个方法实现从服务器下载文件

public void report(String pc){//得到服务器上文件的存放路径
HttpServletResponse response = super.getResponse();
HttpServletRequest request = super.getRequest();
response.setContentType("application/x-msdownload");
//压缩后文件的存放路径
String zipfile = pc.substring(0,76)+"report.zip";//这是我文件的存放路径，存放在tomcat下，如果你也想将文件存放在tomcat下可以使用String dirPath=Thread.currentThread().getContextClassLoader().getResource("").getPath()；
String relPath = pc.substring(0, 85);
 CompressBook book = new CompressBook();
 try {
book.zip(relPath, zipfile);
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}


response.addHeader("Content-Disposition", "attachment;filename=Statements.zip");
FileInputStream fileInputStream = null;
byte[] buf = new byte[1024]; 
int readLength ;
try {
fileInputStream = new FileInputStream(zipfile);

while ((readLength = fileInputStream.read(buf)) != -1) {
response.getOutputStream().write(buf,0,readLength);

}
response.getOutputStream().flush();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
try {
fileInputStream.close();
response.getOutputStream().close();
} catch (Exception e2) {
e2.printStackTrace();
}

}

}

我这个实现了对文件进行压缩后下载，原因是因为我会有多个文件在一个文件夹中。