java Finalize method call
- by Rajesh Kumar J
The following is my Class code
import java.net.*;
import java.util.*;
import java.sql.*;
import org.apache.log4j.*;
class Database {
private Connection conn;
private org.apache.log4j.Logger log ;
private static Database dd=new Database();
private Database(){
try{
log= Logger.getLogger(Database.class);
Class.forName("com.mysql.jdbc.Driver");
conn=DriverManager.getConnection("jdbc:mysql://localhost/bc","root","root");
conn.setReadOnly(false);
conn.setAutoCommit(false);
log.info("Datbase created");
/*Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
conn=DriverManager.getConnection("jdbc:odbc:rmldsn");
conn.setReadOnly(false);
conn.setAutoCommit(false);*/
}
catch(Exception e){
log.info("Cant Create Connection");
}
}
public static Database getDatabase(){
return dd;
}
public Connection getConnection(){
return conn;
}
@Override
protected void finalize()throws Throwable {
try{
conn.close();
Runtime.getRuntime().gc();
log.info("Database Close");
}
catch(Exception e){
log.info("Cannot be closed Database");
}
finally{
super.finalize();
}
}
}
This can able to Initialize Database Object only through getDatabase() method. The below is the program which uses the single Database connection for the 4 threads.
public class Main extends Thread {
public static int c=0;
public static int start,end;
private int lstart,lend;
public static Connection conn;
public static Database dbase;
public Statement stmt,stmtEXE; public ResultSet rst;
/**
* @param args the command line arguments
*/
static{
dbase=Database.getDatabase();
conn=dbase.getConnection();
}
Main(String s){
super(s);
try{
stmt=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
start=end;
lstart=start;
end=end+5;
lend=end;
System.out.println("Start -" +lstart +" End-"+lend);
}
catch(Exception e){
e.printStackTrace();
}
}
@Override
public void run(){
try{
URL url=new URL("http://localhost:8084/TestWeb/");
rst=stmt.executeQuery("SELECT * FROM bc.cdr_calltimestamp limit "+lstart+","+lend);
while(rst.next()){
try{
rst.updateInt(2, 1);
rst.updateRow();
conn.commit();
HttpURLConnection httpconn=(HttpURLConnection) url.openConnection();
httpconn.setDoInput(true);
httpconn.setDoOutput(true);
httpconn.setRequestProperty("Content-Type", "text/xml");
//httpconn.connect();
String reqstring="<?xml version=\"1.0\" encoding=\"US-ASCII\"?>"+
"<message><sms type=\"mt\"><destination messageid=\"PS0\"><address><number" +
"type=\"international\">"+ rst.getString(1) +"</number></address></destination><source><address>" +
"<number type=\"unknown\"/></address></source><rsr type=\"success_failure\"/><ud" +
"type=\"text\">Hello World</ud></sms></message>";
httpconn.getOutputStream().write(reqstring.getBytes(), 0, reqstring.length());
byte b[]=new byte[httpconn.getInputStream().available()];
//System.out.println(httpconn.getContentType());
httpconn.getInputStream().read(b);
System.out.println(Thread.currentThread().getName()+new String(" Request"+rst.getString(1)));
//System.out.println(new String(b));
httpconn.disconnect();
Thread.sleep(100);
}
catch(Exception e){
e.printStackTrace();
}
}
System.out.println(Thread.currentThread().getName()+" "+new java.util.Date());
}
catch(Exception e){
e.printStackTrace();
}
}
public static void main(String[] args) throws Exception{
System.out.println(new java.util.Date());
System.out.println("Memory-before "+Runtime.getRuntime().freeMemory());
Thread t1=new Main("T1-");
Thread t2=new Main("T2-");
Thread t3=new Main("T3-");
Thread t4=new Main("T4-");
t1.start();
t2.start();
t3.start();
t4.start();
System.out.println("Memory-after "+Runtime.getRuntime().freeMemory());
}
}
I need to Close the connection after all the threads gets executed. Is there any good idea to do so. Kindly help me out in getting this work.
