在我的应用程序中，我从文件中获取数据并传输到数据库。我有40万条记录。首先，它将数据快速传输到10 000条记录，然后更新速度非常慢。 Hw是否可以提高将数据传输到db的性能？
gc有问题吗？
这是我的代码：
package com.fileupload;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Iterator;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.swing.text.ZoneView;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.InputStream;
import java.util.Iterator;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.SharedStringsTable;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;
public class SendDataToDb extends HttpServlet{
PreparedStatement ps = null;
HttpSession hs;
Connection con1;
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
hs = request.getSession(false);
try {
Class.forName("com.mysql.jdbc.Driver");
con1 = DriverManager.getConnection("jdbc:mysql://localhost:3306/xlsx","root","Inf123#");
ps = con1.prepareStatement("INSERT INTO userdetails(ID, NAME, AGE, GENDER,ADDRESS, ZONEID, LOCATION) VALUES(?, ?, ?, ?, ?, ?, ?)");
} catch (ClassNotFoundException e1) {
e1.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
try {
processOneSheet("C:/Users/Penchalaiah/Desktop/New folder/"+hs.getAttribute("filename1"));
System.out.println("clossing the connnection");
ps.close();
con1.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public void processOneSheet(String filename) throws Exception {
OPCPackage pkg = OPCPackage.open(filename);
XSSFReader r = new XSSFReader( pkg );
SharedStringsTable sst = r.getSharedStringsTable();
XMLReader parser = fetchSheetParser(sst);
// To look up the Sheet Name / Sheet Order / rID,
// you need to process the core Workbook stream.
// Normally it's of the form rId# or rSheet#
InputStream sheet2 = r.getSheet("rId2");
InputSource sheetSource = new InputSource(sheet2);
parser.parse(sheetSource);
sheet2.close();
}
public XMLReader fetchSheetParser(SharedStringsTable sst) throws SAXException {
XMLReader parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
ContentHandler handler = new SheetHandler(sst);
parser.setContentHandler(handler);
return parser;
}
/**
* See org.xml.sax.helpers.DefaultHandler javadocs
*/
private class SheetHandler extends DefaultHandler {
private SharedStringsTable sst;
private String lastContents;
private boolean nextIsString;
String id;
String names;
String age;
String gender;
String address;
int i = 1;
private SheetHandler(SharedStringsTable sst) {
this.sst = sst;
}
public void startElement(String uri, String localName, String name,
Attributes attributes) throws SAXException {
// c => cell
if(name.equals("c")) {
// Print the cell reference
// Figure out if the value is an index in the SST
String cellType = attributes.getValue("t");
if(cellType != null && cellType.equals("s")) {
nextIsString = true;
} else {
nextIsString = false;
}
}
// Clear contents cache
lastContents = "";
//System.out.println("===>"+lastContents+"<====");
}
public void endElement(String uri, String localName, String name)
throws SAXException {
// Process the last contents as required.
// Do now, as characters() may be called more than once
if(nextIsString) {
int idx = Integer.parseInt(lastContents);
lastContents = new XSSFRichTextString(sst.getEntryAt(idx)).toString();
nextIsString = false;
}
// v => contents of a cell
// Output after we've seen the string contents
if(name.equals("v")) {
System.out.print(lastContents+"\t");
if(i == 1){
id = lastContents;
System.out.print(lastContents+"("+i+")");
}
if(i == 2){
names = lastContents;
System.out.print(lastContents+"("+i+")");
}
if(i == 3){
age = lastContents;
System.out.print(lastContents+"("+i+")");
}
if(i == 4){
gender = lastContents;
System.out.print(lastContents+"("+i+")");
}
if(i == 5){
address = lastContents;
System.out.print(lastContents+"("+i+")");
insertInToDb(id, names, age, gender, address);
i = 0;
}
i++;
}
}
public void characters(char[] ch, int start, int length)
throws SAXException {
lastContents += new String(ch, start, length);
}
}
public void insertInToDb(String id,String names,String age, String gender,String address){
try {
ps.setString(1, id);
ps.setString(2, names);
ps.setString(3, age);
ps.setString(4, gender);
ps.setString(5, address);
ps.setString(6, (String)hs.getAttribute("zoneId1"));
ps.setString(7, (String)hs.getAttribute("location1"));
ps.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
答案 0 :(得分：1)
对多个记录执行一个批处理操作要比为多个记录执行每个插入查询要快得多。
您可以创建10000或任何您想要的批次，然后执行批处理。
Connection con = null;
PreparedStatement pstm = null;
try {
Class.forName("driver class");
con = DriverManager.
getConnection("connectionUrlString","password");
con.setAutoCommit(false);
pstm = con.prepareStatement("your insert command );
pstm .setInt(1, 3000); //set all parameters
pst.addBatch();
int count[] = pst.executeBatch();
for(int i=1;i<=count.length;i++){
System.out.println("Query "+i+" has effected "+count[i]+" records");
}
con.commit();
pst.close();
con.close();