原来采用
RS直接返回结果集进行计数5000行写入文件,每次都出现java heap space
对tomcat的catalina.bat文件加入
JAVA_OPTS=-Xmx512M
后生成文件效率提高,但生成20左右文件时还是会出现java heap space
后采用rownum分页
1
//////这儿进行分指定行生成xml文件
2
3 int ipage=xmlfilenum; //分页单位
4 int allpage=0; //总页数
5 //int pages=0; //接受的页码变量
6 int cpage=1; //当前页
7 //int spage=0; //开始页
8 int allCol=0;
9 //Vector v=null;
10 String sql,pagesql,ssql2;
11 ssql2=FileName;
12
13// 取总文章数
14 pagesql = "SELECT COUNT(*) FROM "+ssql2;
15 //statement = conn.createStatement();
16 rs=excuteQuery(pagesql);
17 //pagers = statement.executeQuery(pagesql);
18 while(rs.next())
19 {
20
allCol = rs.getInt(1);
21 System.out.println("###############总行数############<BR>");
22 System.out.println(allCol);
23 System.out.println("###########################<BR>");
24
}
25
26 //获得总页面数
27 allpage = (int)Math.ceil((allCol + ipage-1) / ipage);
28
29 for(cpage=1;cpage<=allpage;cpage++)
30 {
31 sql="select * from (select rownum no,t.* from "+ssql2 +" t where rownum<"+cpage*ipage+") where no>"+(cpage-1)*ipage;
32 t_FileNameCount=cpage;
33 DataOutputStream t_Output=null;
34 t_FileName = "";
35 t_FileName = fTmpXmlPreDir + "\\" + FileName + "Xml\\" + FileName + "_" + t_FileNameCount + "_" + "Xml.xml";
36 fTmpXmlFileName.add(t_FileName);//存储文件名包括路径
37 //fTmpXmlFileName2.add(FileName + "Xml/" + FileName + "_" + t_FileNameCount + "_" + "Xml.xml");//存储文件名不包括路径
38 t_Output = new DataOutputStream (new BufferedOutputStream(new FileOutputStream(t_FileName)));
39 t_Output.write(t_PreData.getBytes("UTF8"));
40 //先在文件中将xml文档的所有头部描述 部分写入
41
42 rs=excuteQuery(sql);
43 while(rs.next())
44
{
45 String t_aRowData = "";
46 for( int i1=0 ; i1 < this.columnNames.length ; ++i1)
47 {
48 if (rs.getString(i1+2)!=null)//+2 跳过分页时的no字段
49 {
50 t_aRowData = t_aRowData + " Col" + i1 + "=\"" + rs.getString(i1+2) + "\"";
51
}
52 }
53
54 //t_RowData = t_RowData + "<z:row "+ t_aRowData + " />\n";
55 t_aRowData = "<z:row "+ t_aRowData + " />\n";
56 t_Output.write(t_aRowData.getBytes("UTF8"));
57 }
58 String t_WriteData = " </rs:data>\n </x:PivotCache>\n</xml>\n";
59 t_Output.write(t_WriteData.getBytes("UTF8"));
60 t_Output.close();//每2000行关闭文件，重新创新新文件做准备
61
62 System.gc();
63 } //end for allpage
//////这儿进行分指定行生成xml文件 
2
3
int ipage=xmlfilenum; //分页单位 4
int allpage=0; //总页数 5
//int pages=0; //接受的页码变量 6
int cpage=1; //当前页 7
//int spage=0; //开始页 8
int allCol=0;9
//Vector v=null;10
String sql,pagesql,ssql2;11
ssql2=FileName;12
13
// 取总文章数 14
pagesql = "SELECT COUNT(*) FROM "+ssql2;15
//statement = conn.createStatement();16
rs=excuteQuery(pagesql);17
//pagers = statement.executeQuery(pagesql); 18
while(rs.next())19
{
20
allCol = rs.getInt(1);21
System.out.println("###############总行数############<BR>");22
System.out.println(allCol); 23
System.out.println("###########################<BR>");24
}25
26
//获得总页面数 27
allpage = (int)Math.ceil((allCol + ipage-1) / ipage); 28
29
for(cpage=1;cpage<=allpage;cpage++)30
{ 31
sql="select * from (select rownum no,t.* from "+ssql2 +" t where rownum<"+cpage*ipage+") where no>"+(cpage-1)*ipage;32
t_FileNameCount=cpage;33
DataOutputStream t_Output=null;34
t_FileName = "";35
t_FileName = fTmpXmlPreDir + "\\" + FileName + "Xml\\" + FileName + "_" + t_FileNameCount + "_" + "Xml.xml";36
fTmpXmlFileName.add(t_FileName);//存储文件名包括路径 37
//fTmpXmlFileName2.add(FileName + "Xml/" + FileName + "_" + t_FileNameCount + "_" + "Xml.xml");//存储文件名不包括路径38
t_Output = new DataOutputStream (new BufferedOutputStream(new FileOutputStream(t_FileName)));39
t_Output.write(t_PreData.getBytes("UTF8"));40
//先在文件中将xml文档的所有头部描述 部分写入41
42
rs=excuteQuery(sql);43
while(rs.next())44
{
45
String t_aRowData = "";46
for( int i1=0 ; i1 < this.columnNames.length ; ++i1)47
{48
if (rs.getString(i1+2)!=null)//+2 跳过分页时的no字段49
{50
t_aRowData = t_aRowData + " Col" + i1 + "=\"" + rs.getString(i1+2) + "\"";51
}52
}53
54
//t_RowData = t_RowData + "<z:row "+ t_aRowData + " />\n";55
t_aRowData = "<z:row "+ t_aRowData + " />\n";56
t_Output.write(t_aRowData.getBytes("UTF8"));57
}58
String t_WriteData = " </rs:data>\n </x:PivotCache>\n</xml>\n";59
t_Output.write(t_WriteData.getBytes("UTF8"));60
t_Output.close();//每2000行关闭文件，重新创新新文件做准备61
62
System.gc();63
} //end for allpage终于搞定.细节再调整中