OBJECT DESTRUCTION IN JAVA

Question

import java.io.FileWriter;
import java.io.FileReader;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.MalformedURLException;
import java.io.FileOutputStream;
import au.com.bytecode.opencsv.CSVReader;
import au.com.bytecode.opencsv.CSVWriter;
import java.io.IOException;
import java.lang.ArrayIndexOutOfBoundsException;
import java.io.File;
public class Main {
        static void process(File iFile, File oFile) {
        FileReader input_file = null;
        CSVReader buff_input1 = null;
        BufferedReader buff_input2 = null;
        FileWriter osw_output = null;
        String line;
        String inputline;
        String[] input_record;
        String[] input2_record;
        String lat;
        String level;
    String l3;
        String l1;
        String l2;
        String app;
        String lon;
        URL myurl = null;
        int i = 0;
        try {
            input_file = new FileReader(iFile);
            buff_input1 = new CSVReader(input_file);
            osw_output = new FileWriter(oFile);
            input_record =buff_input1.readNext();
            while((input_record =buff_input1.readNext())!=null) {
               try{
                i = i+1;
                //System.out.println();
                String add1 = input_record[39];
                String add2 = input_record[40];
                String address = (add1+add2);
                address = address.replaceAll("#[^ ]*"," ");
                address = address.replaceAll("( ){2,}"," ");
                address = address.replaceAll("P[.| ]?O[.]? BOX [0-9]*"," ");
                address = address.replaceAll(" PH[^A-Z].*"," ");
                address = address.replaceAll(" STE[^A-Z].*"," ");
                address = address.replaceAll(" UNIT [^ ]*"," ");
                address = address.replaceAll(" APT [^ ]*"," ");
                address = address.replaceAll(" SUITE [^ ]*"," ");
                address = address.replaceAll(" [0-9A-Za-z]* FLOOR"," ");
                address = address.replaceAll("^[^0-9]*"," ");
                address = address.replaceAll("-[0-9][0-9]*"," ");
                address = address.replaceAll("( ){2,}"," ");
                String remaining_fields = (input_record[0]+input_record[1]+input_record[2]+input_record[3]+
                        input_record[4]+input_record[5]+input_record[6]+input_record[7]+
                        input_record[8]+input_record[9]+input_record[10]+input_record[11]+input_record[12]+
                        input_record[13]+input_record[14]+input_record[15]+input_record[16]+
                        input_record[17]+input_record[18]+input_record[19]+input_record[20]+input_record[21]+
                        input_record[22]+input_record[23]+input_record[24]+input_record[25]+
                        input_record[26]+input_record[27]+input_record[28]+input_record[29]+input_record[30]+
                        input_record[31]+input_record[32]+input_record[33]+input_record[34]+
                        input_record[35]+input_record[36]+input_record[37]+input_record[38]+input_record[39]+
                        input_record[40]+input_record[41]+input_record[42]+input_record[43]+input_record[44]+
                        input_record[45]+input_record[46]+input_record[47]+input_record[48]+input_record[49]+
                        input_record[50]+input_record[51]+input_record[52]+input_record[53]+input_record[54]+
                        input_record[55]+input_record[56]+input_record[57]+input_record[58]+input_record[59]+
                        input_record[60]+input_record[61]+input_record[62]+input_record[63]+input_record[64]);
                remaining_fields = remaining_fields.replaceAll("[^ -~]"," ");
                //return address;
               // address(address);
                String city = input_record[41];
                String state = input_record[42];
                String zip = input_record[43];
        String complete_address = address+","+city+","+state+" "+zip;
                myurl = new URL("http://stree1.cs.fiu.edu:88/street?street="+address+","+city+","+state+" "+zip); // This is where the problem lies, a new object is instatiated everytime the loop is executed.
                buff_input2 = new BufferedReader(new InputStreamReader(myurl.openStream()));
                inputline = buff_input2.readLine();
                input2_record = inputline.split("\t");
                l1 = input2_record[0];
                lat = l1.substring(2);
                l2 = input2_record[1];
                lon = l2.substring(2);
                //System.out.println("the lat:"+lat);
                //System.out.println("the lon:"+lon);
                inputline = buff_input2.readLine();
                input2_record = inputline.split("\t");
                l3 = input2_record[0];
        level = l3.substring(6);
                app  = input2_record[1];
                //System.out.println(level);
                //System.out.println(app);
                osw_output.append(input_record[0]+"\t"+input_record[1]+"\t"+input_record[2]+"\t"+input_record[3]+"\t"+input_record[4]+
                        "\t"+input_record[5]+"\t"+input_record[6]+"\t"+input_record[7]+
                        "\t"+input_record[8]+"\t"+input_record[9]+"\t"+input_record[10]+"\t"+input_record[11]+"\t"+input_record[12]+
                        "\t"+input_record[13]+"\t"+input_record[14]+"\t"+input_record[15]+"\t"+input_record[16]+
                        "\t"+input_record[17]+"\t"+input_record[18]+"\t"+input_record[19]+"\t"+input_record[20]+"\t"+input_record[21]+
                        "\t"+input_record[22]+"\t"+input_record[23]+"\t"+input_record[24]+"\t"+input_record[25]+
                        "\t"+input_record[26]+"\t"+input_record[27]+"\t"+input_record[28]+"\t"+input_record[29]+"\t"+input_record[30]+
                        "\t"+input_record[31]+"\t"+input_record[32]+"\t"+input_record[33]+"\t"+input_record[34]+
                        "\t"+input_record[35]+"\t"+input_record[36]+"\t"+input_record[37]+"\t"+input_record[38]+"\t"+input_record[39]+
                        "\t"+input_record[40]+"\t"+input_record[41]+"\t"+input_record[42]+"\t"+input_record[43]+"\t"+input_record[44]+
                        "\t"+input_record[45]+"\t"+input_record[46]+"\t"+input_record[47]+"\t"+input_record[48]+"\t"+input_record[49]+
                        "\t"+input_record[50]+"\t"+input_record[51]+"\t"+input_record[52]+"\t"+input_record[53]+"\t"+input_record[54]+
                        "\t"+input_record[55]+"\t"+input_record[56]+"\t"+input_record[57]+"\t"+input_record[58]+"\t"+input_record[59]+
                        "\t"+input_record[60]+"\t"+input_record[61]+"\t"+input_record[62]+"\t"+input_record[63]+"\t"+input_record[64]+
                        "\t"+lat+"\t"+lon+"\t"+level+"\t"+app);
                osw_output.append((char)13);
                osw_output.append((char)10);
                buff_input2.close();
                //System.out.println("Reached end of loop");
               catch(ArrayIndexOutOfBoundsException e)
                   String[] s = input_record;
            System.out.println("Malformed record located at row" + s + "system ignoring record and continuing");
    finally
             myurl = null;
         System.gc();// this is what I am using reluctantly, because when I run multiple instances of this program on different files, some processes are sitting idle. System.gc() helped me solve that problem but has made the system very slow. Is there a more efficient way of doing this?
            osw_output.flush();
            osw_output.close();
            input_file.close();
        } catch(MalformedURLException e) {
            System.out.println("IO ERROR!:"+e.getMessage());
        } catch(IOException ee) {
            System.out.println("URL ERROR!:"+ee.getMessage());
    public static void main(String[] args) {
        File iFile = new File(args[0]);
        File oFile = null;
        oFile =  new File(args[1]);
        process(iFile, oFile);
}In the above program I am supposed to read a file and add certain contants of the file to a URL and read back those results into another file. so in the while loop each record is executed one after the other. to do this I make a new URL object everytime in the while loop. This is ok when I run the program once. but if I multiple instances of the program on different files, some java processes just sit idol. I could determine that the URL objects were creating the problem and therefore I added (the Highly unrecommended) System.gc() in my finally block, which makes the program work like I want it to but has made the system extremely slow. Is there a more efficient way someone can suggest?...thank you.

Answer 1

jdkguy wrote:
In the above program I am supposed to read a file and add certain contants of the file to a URL and read back those results into another file. so in the while loop each record is executed one after the other. to do this I make a new URL object everytime in the while loop. This is ok when I run the program once. but if I multiple instances of the program on different files, some java processes just sit idol. I could determine that the URL objects were creating the problem and therefore I added (the Highly unrecommended) System.gc() in my finally block, which makes the program work like I want it to but has made the system extremely slow. Is there a more efficient way someone can suggest?...thank you.I didn't see anything that would cause other instances to block, other than maybe not closing the CSVReader, but I doubt that's it. How did you determine that some processes were idle? Are you running a profiler?
By the way, this:
                String remaining_fields = (input_record[0]+input_record[1]+input_record[2]+input_record[3]+
                        input_record[4]+input_record[5]+input_record[6]+input_record[7]+
                        input_record[8]+input_record[9]+input_record[10]+input_record[11]+input_record[12]+
                        input_record[13]+input_record[14]+input_record[15]+input_record[16]+
                        input_record[17]+input_record[18]+input_record[19]+input_record[20]+input_record[21]+
                        input_record[22]+input_record[23]+input_record[24]+input_record[25]+
                        input_record[26]+input_record[27]+input_record[28]+input_record[29]+input_record[30]+
                        input_record[31]+input_record[32]+input_record[33]+input_record[34]+
                        input_record[35]+input_record[36]+input_record[37]+input_record[38]+input_record[39]+
                        input_record[40]+input_record[41]+input_record[42]+input_record[43]+input_record[44]+
                        input_record[45]+input_record[46]+input_record[47]+input_record[48]+input_record[49]+
                        input_record[50]+input_record[51]+input_record[52]+input_record[53]+input_record[54]+
                        input_record[55]+input_record[56]+input_record[57]+input_record[58]+input_record[59]+
                        input_record[60]+input_record[61]+input_record[62]+input_record[63]+input_record[64]);is horrible. There's no reason to copy and paste all those elements individually, use a loop:
String remaining_fields = "";
for (int i=0; i<=64; i++) {
    remaining_fields += input_record;
}for (