POI操作Excel2007实例二之“SXSSFWorkbook”处理海量数据

转自：http://blog.csdn.net/little_stars/article/details/8266262

前文讲述了 POI 读取的基本操作，但后期 经过试验，当写入数据量超过5万条以上时，

很容易报错“内存溢出”，就算你调整JVM的xmx为 “2048MB”，也无效果。

后来查资料得知 SXSSFWorkbook 是专门用来处理大量数据写入 Excel2007的问题的。


实例如下，具体步骤神马的，请看前文。

读取仍然是“XSSFWorkbook”，写入则为“SXSSFWorkbook ”。

经试验 写入处理速度在 7000行左右，根据 Excel文件大小 会上下浮动。



Config.java

[java] view plaincopyprint?
    1. package com.excel.poi.gz10000;  
    2. import java.io.BufferedInputStream;  
    3. import java.io.File;  
    4. import java.io.FileInputStream;  
    5. import java.io.FileOutputStream;  
    6. import java.io.IOException;  
    7. import java.io.UnsupportedEncodingException;  
    8. import java.sql.Connection;  
    9. import java.sql.DriverManager;  
    10. import java.sql.ResultSet;  
    11. import java.sql.SQLException;  
    12. import java.sql.Statement;  
    13. import java.text.DecimalFormat;  
    14. import java.text.NumberFormat;   
    15. import java.text.SimpleDateFormat;  
    16. import java.util.ArrayList;  
    17. import java.util.Date;  
    18.   
    19. import javax.servlet.ServletException;  
    20. import javax.servlet.http.HttpServlet;  
    21. import javax.servlet.http.HttpServletRequest;  
    22. import javax.servlet.http.HttpServletResponse;  
    23.    
    24. import org.apache.log4j.Logger;  
    25. import org.apache.log4j.PropertyConfigurator;  
    26. import org.apache.poi.ss.usermodel.Cell;  
    27. import org.apache.poi.ss.usermodel.Row;  
    28. import org.apache.poi.ss.usermodel.Sheet;  
    29. import org.apache.poi.xssf.streaming.SXSSFWorkbook;  
    30. import org.apache.poi.xssf.usermodel.XSSFCell;         
    31. import org.apache.poi.xssf.usermodel.XSSFWorkbook;  
    32.   
    33. /** 
    34.  * <b> 数据匹配</b> <br> 
    35.  * <ul> 
    36.  * <li> 作者：C_Dream </li> 
    37.  * <li> 当前版本：4.0 </li> 
    38.  * <li> 修改时间： 2012-12-6 17:50 </li> 
    39.  * <li> 修改内容：<ol> 
    40.  * <li> 更换Excel2007写入方式，大幅提升性能。</li> 
    41.  * <li> 引入 log4j，局部提升性能。</li> 
    42.  * <li> 部分代码优化，CMD输出提示可选。</li> 
    43.  * </ol></li> 
    44.  * <li> 创建时间： 2012-11-08 19:22 </li> 
    45.  * </ul> 
    46.  */  
    47. public class Config extends HttpServlet{  
    48.     private static final long serialVersionUID = 1L;       
    49.     //Config c = new Config();//此处决不能 new 本类，否则报错：java.lang.StackOverflowError  
    50.     String class_path = this.getClass().getResource("").getPath();   
    51.     public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException  
    52.     {  
    53.         this.doGet(request,response); //将 表单  post 方法传过来的参数，转给 get方法 去处理  
    54.     }  
    55.     public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException, IOException   
    56.     {  
    57.          request.setCharacterEncoding("UTF-8"); //转码  
    58.          String forms=(String)request.getParameter("forms");  
    59.   
    60.          if(forms.equals("if_3g")){  
    61.                 try {  
    62.                     this.read_Excel(request,response);  
    63.                 } catch (SQLException e) {  
    64.                     e.printStackTrace();  
    65.                 } catch (ClassNotFoundException e) {  
    66.                     e.printStackTrace();  
    67.                 }    
    68.          }  
    69.                    
    70.          response.sendRedirect("index.jsp?done=true");  
    71.     }   
    72.       
    73.       
    74.     @SuppressWarnings("rawtypes")  
    75.     public void read_Excel(HttpServletRequest request,  
    76.             HttpServletResponse response) throws UnsupportedEncodingException, SQLException, ClassNotFoundException  {  
    77.           
    78.         PropertyConfigurator.configure(class_path+"log4j.properties");//获取 log4j 配置文件  
    79.         Logger logger = Logger.getLogger(Config.class ); //获取log4j的实例  
    80.         String startTmie = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date());  
    81.         logger.debug(" **********【准备处理，正在加载文件】**********");//7  
    82.         logger.debug(" **********每行数据间请不要有空行，以免程序误判**********");//7  
    83.         logger.debug(" **********由于处理Excel的插件本身性能局限，请控制文件大小，以免影响加载效率。**********");//7  
    84.         logger.debug(" **********大小在  7 MB  以内，大约  21 万  行数据。**********");//7  
    85.         logger.debug(" **********本程序每分钟约处理 7000条数据，但根据文件大小会有影响。**********");//7  
    86.           
    87.         request.setCharacterEncoding("UTF-8");  //转码  
    88.         String xls_read_Address=(String)request.getParameter("xls_read_Address");//读取     
    89.         String xls_write_Address=(String)request.getParameter("xls_write_Address");//写入  
    90.         String  count_rows=(String)request.getParameter("count_rows");//自动编号      
    91.         String  tips_cmd=(String)request.getParameter("tips_cmd");//CMD窗口的提示方式  
    92.           
    93.         try {   
    94.             DataConvert dc = new DataConvert();//数据转换工具  
    95.             DecimalFormat df = (DecimalFormat) NumberFormat.getPercentInstance();   
    96.               
    97.             ArrayList<ArrayList> ls = new  ArrayList<ArrayList>();  
    98.       
    99.             File excel_file = new File(xls_read_Address);//读取的文件路径    
    100.             FileInputStream input = new FileInputStream(excel_file);  //读取的文件路径   
    101.             XSSFWorkbook wb = new XSSFWorkbook(new BufferedInputStream(input));                    
    102.             int sheet_numbers = wb.getNumberOfSheets();//获取表的总数  
    103.             logger.debug(" **********共有工作表总数**********："+sheet_numbers);//7    
    104.             String[] sheetnames=new String[sheet_numbers];  
    105.               
    106.             Connection con=null;  
    107.             Statement  stmt=null;  
    108.             ResultSet  rs=null;  
    109.             String s_3g=null;             
    110.             Class.forName("oracle.jdbc.driver.OracleDriver");  
    111.             con = DriverManager.getConnection("jdbc:oracle:thin:@12.12.12.123:1521:gz10000","gz12345","12345");  
    112.             stmt = con.createStatement();     
    113.               
    114.             for(int i=0;i<sheet_numbers;i++){//遍历所有表               
    115.                 ArrayList<String[]> ls_a = new  ArrayList<String[]>(); //用来存储某个表 读取出来的数据    
    116.                 Sheet sheet = wb.getSheetAt(i);  //获取 某个表                
    117.                 sheetnames[i] = sheet.getSheetName();//获取表名，存入数组  
    118.                 logger.debug(" ---正在读取和匹配工作表 《"+sheetnames[i]+"》 的数据--- ");//7   
    119.                   
    120.                 int rows_num = sheet.getLastRowNum();//获取行数  
    121.                 logger.debug(" ---表 《"+sheetnames[i]+"》  共有数据---： "+rows_num+" 行");//7   
    122.                 for( int rows=0;rows<rows_num;rows++){   
    123.                     Row row = sheet.getRow(rows);//取得某一行   对象                                     
    124.                       
    125.                     if(row!=null&&!(row.equals(""))){  
    126.                     int columns_num = row.getLastCellNum();//获取列数  
    127.                       
    128.                     String[] s =new String[5];//初始化数组长度  
    129.                     for( int columns=0;columns<columns_num;columns++){  
    130.                         Cell  cell = row.getCell(columns);                    
    131.                         if(cell!=null){   
    132.                         switch ( cell.getCellType()) {    
    133.                          case XSSFCell.CELL_TYPE_STRING: // 字符串     
    134.                              s[columns] = cell.getStringCellValue();    
    135.                              if(s[columns]==null){  
    136.                                  s[columns]=" ";  
    137.                              }  
    138.                              break;   
    139.                          case XSSFCell.CELL_TYPE_NUMERIC: // 数字                            
    140.                                 double strCell = cell.getNumericCellValue();  
    141.                              if(String.valueOf(strCell)==null){  
    142.                                  s[columns]=" ";  
    143.                              }    
    144.                                       
    145.                                 df.applyPattern("0");  
    146.                                 s[columns] = df.format(strCell);  
    147.                                 if(Double.parseDouble(s[columns])!=strCell){  
    148.                                  df.applyPattern(Double.toString(strCell));  
    149.                                  s[columns] = df.format(strCell);  
    150.                                 }  
    151.                                
    152.                              break;  
    153.                          case XSSFCell.CELL_TYPE_BLANK: // 空值     
    154.                              s[columns]=" ";    
    155.                              break;     
    156.                          default:    
    157.                              logger.debug(" ---单元格格式不支持---");      
    158.                              break;     
    159.                          }    
    160.                        }  
    161.                     }  
    162.                     if(count_rows.equals("是")&&rows>0){  
    163.                         s[0]=dc.intToString(rows);//自动编号  
    164.                     }  
    165.                       
    166.                     /* ******** 访问数据库 ，并判断是否3G ******** */  
    167.                     String sql="select busiattr1 from ap_t_si_cus_spec_info where cus_phone='"+s[1]+"' and rownum=1";                         
    168.                     rs = stmt.executeQuery(sql);  
    169.                       
    170.                     if(rs.next()){  
    171.                         if(rs.getString("busiattr1")!=null){  
    172.                             s_3g = rs.getString("busiattr1").toString().toUpperCase();  
    173.                         }  
    174.                         else{  
    175.                             s_3g=" ";  
    176.                         }  
    177.                     }  
    178.                     else{  
    179.                         s_3g=" ";  
    180.                     }   
    181.                     /* ******** 访问结束  ******** */  
    182.                       
    183.                     if(s_3g.contains("3G")){  
    184.                         s[4]="是";//写入 “是否3G”这一列 的值，比如 “是”  
    185.                     }  
    186.                     if(s[4]==null){  
    187.                         s[4]=" ";  
    188.                     }  
    189.                       
    190.                     /* CMD窗口提示方式 */  
    191.                     if(!(tips_cmd.equals("none"))&&tips_cmd!=null&&!(tips_cmd.equals(""))) {  
    192.                         if(tips_cmd.equals("all")){  
    193.                             logger.debug(" 匹配中："+s[0]+" "+s[1]+" "+s[2]+" "+s[3]+" "+ s[4]);   
    194.                         }else                 
    195.                         if(rows%DataConvert.stringToInt(tips_cmd)==0){  
    196.                             logger.debug(" 匹配中："+s[0]+" "+s[1]+" "+s[2]+" "+s[3]+" "+ s[4]);   
    197.                         }  
    198.                     }  
    199.                       
    200.                     ls_a.add(s);//添加每行数据到 ls_a  
    201.                     }  
    202.                 }  
    203.             ls.add(ls_a);       //添加 每个表 到 ls              
    204.             input.close();     
    205.             write_Excel( xls_write_Address, ls, sheetnames ,tips_cmd)  ;                  
    206.             }              
    207.         } catch (IOException ex) {    
    208.             ex.printStackTrace();    
    209.         }  
    210.         String endTmie = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date());  
    211.         logger.debug(" ***************【处理完成，程序结束】***************");//7     
    212.         logger.debug(" 开始时间："+startTmie);  
    213.         logger.debug(" 结束时间："+endTmie);   
    214.         logger.debug(" 新文件输出路径为："+xls_write_Address);  
    215.     }  
    216.   
    217.     @SuppressWarnings({ "rawtypes", "unchecked" })  
    218.     public void write_Excel( String xls_write_Address,ArrayList<ArrayList> ls,String[] sheetnames,String tips_cmd ) throws IOException  {  
    219.            
    220.         PropertyConfigurator.configure(class_path+"log4j.properties");//获取 log4j 配置文件  
    221.         Logger logger = Logger.getLogger(Config.class ); //获取log4j的实例         
    222.         FileOutputStream output = new FileOutputStream(new File(xls_write_Address));  //读取的文件路径   
    223.         SXSSFWorkbook wb = new SXSSFWorkbook(10000);//内存中保留 10000 条数据，以免内存溢出，其余写入 硬盘          
    224.           
    225.           
    226.         for(int sn=0;sn<ls.size();sn++){  
    227.             Sheet sheet = wb.createSheet(String.valueOf(sn));  
    228.   
    229.             wb.setSheetName(sn, sheetnames[sn]);     
    230.             ArrayList<String[]> ls2 = ls.get(sn);   
    231.             for(int i=0;i<ls2.size();i++){  
    232.                 Row row = sheet.createRow(i);  
    233.                 String[] s = ls2.get(i);                  
    234.                 for(int cols=0;cols<s.length;cols++){  
    235.                     Cell cell = row.createCell(cols);                     
    236.                     cell.setCellType(XSSFCell.CELL_TYPE_STRING);//文本格式                    
    237.                     sheet.setColumnWidth(cols, s[cols].length()*384); //设置单元格宽度  
    238.                     cell.setCellValue(s[cols]);//写入内容  
    239.                 }  
    240.                 /* CMD窗口提示方式 */  
    241.                 if(!(tips_cmd.equals("none"))&&tips_cmd!=null&&!(tips_cmd.equals(""))) {  
    242.                     if(tips_cmd.equals("all")){  
    243.                         logger.debug(" 写入中："+s[0]+" "+s[1]+" "+s[2]+" "+s[3]+" "+ s[4]);   
    244.                     }else                 
    245.                     if(i%DataConvert.stringToInt(tips_cmd)==0){  
    246.                         logger.debug(" 写入中："+s[0]+" "+s[1]+" "+s[2]+" "+s[3]+" "+ s[4]);   
    247.                     }  
    248.                 }  
    249.             }              
    250.          }    
    251.         wb.write(output);  
    252.         output.close();           
    253.     }  
    254.        
    255. } 
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原文地址：https://www.cnblogs.com/liuzy2014/p/5010426.html