Java实现大批量数据导入导出(100W以上) -（二）导出

使用POI或JXLS导出大数据量（百万级）Excel报表常常面临两个问题：

1. 服务器内存溢出；

2. 一次从数据库查询出这么大数据，查询缓慢。

当然也可以分页查询出数据，分别生成多个Excel打包下载，但这种生成还是很缓慢。

大数据量导入请参考：Java实现大批量数据导入导出(100W以上)　-（一）导入

那么如何解决呢？

我们可以借助XML格式利用模板替换，分页查询出数据从磁盘写入XML，最终会以Excel多sheet形式生成。亲测2400万行数据，生成Excel文件4.5G，总耗时1.5分钟。

 

我利用StringTemplate模板解析技术对XML模板进行填充。当然也可以使用FreeMarker, Velocity等Java模板技术实现。

首先引入StringTemplate所需Jar包：

使用技术为 stringTemplate 

pom.xml：

 1 　　<dependency>
 2             <groupId>antlrgroupId>
 3             <artifactId>antlrartifactId>
 4             <version>2.7.7version>
 5         dependency>
 6 
 7         <dependency>
 8             <groupId>org.antlrgroupId>
 9             <artifactId>stringtemplateartifactId>
10             <version>3.2.1version>
11         dependency>

 

首先准备导出Excel模板，然后打开－》另存为－》选择格式为XML，然后用文本打开XML,提取XML头模板(head.st可通用)，数据体模板(boday.st):

head.st可通用:

 1 xml version="1.0"?>
 2 mso-application progid="Excel.Sheet"?>
 3 <Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 4  xmlns:o="urn:schemas-microsoft-com:office:office"
 5  xmlns:x="urn:schemas-microsoft-com:office:excel"
 6  xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
 7  xmlns:html="http://www.w3.org/TR/REC-html40">
 8  <DocumentProperties xmlns="urn:schemas-microsoft-com:office:office">
 9   <Created>1996-12-17T01:32:42ZCreated>
10   <LastSaved>2013-08-02T09:21:24ZLastSaved>
11   <Version>11.9999Version>
12  DocumentProperties>
13  <OfficeDocumentSettings xmlns="urn:schemas-microsoft-com:office:office">
14   <RemovePersonalInformation/>
15  OfficeDocumentSettings>
16  <ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">
17   <WindowHeight>4530WindowHeight>
18   <WindowWidth>8505WindowWidth>
19   <WindowTopX>480WindowTopX>
20   <WindowTopY>120WindowTopY>
21   <AcceptLabelsInFormulas/>
22   <ProtectStructure>FalseProtectStructure>
23   <ProtectWindows>FalseProtectWindows>
24  ExcelWorkbook>
25  <Styles>
26   <Style ss:ID="Default" ss:Name="Normal">
27    <Alignment ss:Vertical="Bottom"/>
28    <Borders/>
29    <Font ss:FontName="宋体" x:CharSet="134" ss:Size="12"/>
30    <Interior/>
31    <NumberFormat/>
32    <Protection/>
33   Style>
34  Styles>

 

boday.st:

 

 1  $worksheet:{
 2  <Worksheet ss:Name="$it.sheet$">
 3   <Table ss:ExpandedColumnCount="$it.columnNum$" ss:ExpandedRowCount="$it.rowNum$" x:FullColumns="1"
 4    x:FullRows="1" ss:DefaultColumnWidth="54" ss:DefaultRowHeight="14.25">
 5  $it.rows:{
 6    <Row>
 7     <Cell><Data ss:Type="String">$it.name1$Data>Cell>
 8     <Cell><Data ss:Type="String">$it.name2$Data>Cell>
 9     <Cell><Data ss:Type="String">$it.name3$Data>Cell>
10    Row>
11  }$
12   Table>
13  Worksheet>
14 }$

 

生成大数据量Excel类：

ExcelGenerator:

  1 package test.exportexcel;
  2 
  3 import org.antlr.stringtemplate.StringTemplate;
  4 import org.antlr.stringtemplate.StringTemplateGroup;
  5 import test.exportexcel.bean.Row;
  6 import test.exportexcel.bean.Worksheet;
  7 
  8 import java.io.*;
  9 import java.util.ArrayList;
 10 import java.util.List;
 11 import java.util.Random;
 12 
 13 /**
 14  * 类功能描述：generator big data Excel
 15  *
 16  * @author WangXueXing create at 19-4-13 下午10:23
 17  * @version 1.0.0
 18  */
 19 public class ExcelGenerator {
 20     public static void main(String[] args) throws FileNotFoundException{
 21         ExcelGenerator template = new ExcelGenerator();
 22         template.output2();
 23     }
 24 
 25     /**
 26      * 生成数据量大的时候，该方法会出现内存溢出
 27      * @throws FileNotFoundException
 28      */
 29     public void output1() throws FileNotFoundException{
 30         StringTemplateGroup stGroup = new StringTemplateGroup("stringTemplate");
 31         StringTemplate st4 =  stGroup.getInstanceOf("test/exportexcel/template/test");
 32         List worksheets = new ArrayList<>();
 33 
 34         File file = new File("/home/barry/data/output.xls");
 35         PrintWriter writer = new PrintWriter(new BufferedOutputStream(new FileOutputStream(file)));
 36 
 37         for(int i=0;i<30;i++){
 38             Worksheet worksheet = new Worksheet();
 39             worksheet.setSheet("第"+(i+1)+"页");
 40             List rows = new ArrayList<>();
 41             for(int j=0;j<6000;j++){
 42                 Row row = new Row();
 43                 row.setName1("zhangzehao");
 44                 row.setName2(""+j);
 45                 row.setName3(i+" "+j);
 46                 rows.add(row);
 47             }
 48             worksheet.setRows(rows);
 49             worksheets.add(worksheet);
 50         }
 51 
 52         st4.setAttribute("worksheets", worksheets);
 53         writer.write(st4.toString());
 54         writer.flush();
 55         writer.close();
 56         System.out.println("生成excel完成");
 57     }
 58 
 59     /**
 60      * 该方法不管生成多大的数据量，都不会出现内存溢出，只是时间的长短
 61      * 经测试，生成2400万数据，2分钟内，4.5G大的文件，打开大文件就看内存是否足够大了
 62      * 数据量小的时候，推荐用JXLS的模板技术生成excel文件，谁用谁知道，大数据量可以结合该方法使用
 63      * @throws FileNotFoundException
 64      */
 65     public void output2() throws FileNotFoundException{
 66         long startTimne = System.currentTimeMillis();
 67         StringTemplateGroup stGroup = new StringTemplateGroup("stringTemplate");
 68 
 69         //写入excel文件头部信息
 70         StringTemplate head =  stGroup.getInstanceOf("test/exportexcel/template/head");
 71         File file = new File("/home/barry/data/output.xls");
 72         PrintWriter writer = new PrintWriter(new BufferedOutputStream(new FileOutputStream(file)));
 73         writer.print(head.toString());
 74         writer.flush();
 75 
 76         int sheets = 400;
 77         //excel单表最大行数是65535
 78         int maxRowNum = 60000;
 79 
 80         //写入excel文件数据信息
 81         for(int i=0;i){
 82             StringTemplate body =  stGroup.getInstanceOf("test/exportexcel/template/body");
 83             Worksheet worksheet = new Worksheet();
 84             worksheet.setSheet(" "+(i+1)+" ");
 85             worksheet.setColumnNum(3);
 86             worksheet.setRowNum(maxRowNum);
 87             List rows = new ArrayList<>();
 88             for(int j=0;j){
 89                 Row row = new Row();
 90                 row.setName1(""+new Random().nextInt(100000));
 91                 row.setName2(""+j);
 92                 row.setName3(i+""+j);
 93                 rows.add(row);
 94             }
 95             worksheet.setRows(rows);
 96             body.setAttribute("worksheet", worksheet);
 97             writer.print(body.toString());
 98             writer.flush();
 99             rows.clear();
100             rows = null;
101             worksheet = null;
102             body = null;
103             Runtime.getRuntime().gc();
104             System.out.println("正在生成excel文件的 sheet"+(i+1));
105         }
106 
107         //写入excel文件尾部
108         writer.print("");
109         writer.flush();
110         writer.close();
111         System.out.println("生成excel文件完成");
112         long endTime = System.currentTimeMillis();
113         System.out.println("用时="+((endTime-startTimne)/1000)+"秒");
114     }
115 }

 

定义JavaBean:

WorkSheet.java:

 1 package test.exportexcel.bean;
 2 
 3 import java.util.List;
 4 
 5 /**
 6  * 类功能描述：Excel sheet Bean
 7  *
 8  * @author WangXueXing create at 19-4-13 下午10:21
 9  * @version 1.0.0
10  */
11 public class Worksheet {
12     private String sheet;
13     private int columnNum;
14     private int rowNum;
15     private List rows;
16 
17     public String getSheet() {
18         return sheet;
19     }
20     public void setSheet(String sheet) {
21         this.sheet = sheet;
22     }
23 
24     public List getRows() {
25         return rows;
26     }
27     public void setRows(List rows) {
28         this.rows = rows;
29     }
30 
31     public int getColumnNum() {
32         return columnNum;
33     }
34     public void setColumnNum(int columnNum) {
35         this.columnNum = columnNum;
36     }
37 
38     public int getRowNum() {
39         return rowNum;
40     }
41     public void setRowNum(int rowNum) {
42         this.rowNum = rowNum;
43     }
44 }

 

Row.java:

 1 package test.exportexcel.bean;
 2 
 3 /**
 4  * 类功能描述：Excel row bean
 5  *
 6  * @author WangXueXing create at 19-4-13 下午10:22
 7  * @version 1.0.0
 8  */
 9 public class Row {
10     private String name1;
11     private String name2;
12     private String name3;
13 
14     public String getName1() {
15         return name1;
16     }
17     public void setName1(String name1) {
18         this.name1 = name1;
19     }
20 
21     public String getName2() {
22         return name2;
23     }
24     public void setName2(String name2) {
25         this.name2 = name2;
26     }
27 
28     public String getName3() {
29         return name3;
30     }
31     public void setName3(String name3) {
32         this.name3 = name3;
33     }
34 }

 

另附实现源码：　exportexcel.zip