Java ArrayList - I am creating an arraylist of objects but when I loop over and print it, only the last object is printed 7(size of arraylist) times

Question

My problem is in my readFiles() method where I am creating ArrayList<LogEntry> records.

public class LogAnalyzer  {
    private static ArrayList<LogEntry> records;
    static ReadJavaDoc obj = new ReadJavaDoc();

    public LogAnalyzer() {
        records = new ArrayList<LogEntry>();
    }

    public static void readFiles(String str) throws FileNotFoundException {
        for (String s : obj.linesOfFile(str)) {
            LogEntry entry = WebLogParser.parseEntry(s);
            records.add(entry);
        }

        for (LogEntry i : records) {
            System.out.println(i);
        }
    }
    
    public static void main(String[] args) throws FileNotFoundException {
        new LogAnalyzer();
        readFiles(filePath);
    }
}

I have a toString() method in my LogEntry and by looping over, I was expecting each entry to be printed on a separate line.

However, only the last object got printed 7 times.

Other classes:

public class WebLogParser {
    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MMM/yyyy:kk:mm:ss Z", Locale.US);
    private static String munchTo(StringBuilder sb, String delim) {
        int x = sb.indexOf(delim);
        if (x == -1) {
            x = sb.length();
        }
        String ans = sb.substring(0,x);
        sb.delete(0, x + delim.length());
        return ans;
    }
    public static LogEntry parseEntry(String line) {
        //Assumes line is vald and in this format:
        //110.76.104.12 - - [30/Sep/2015:07:47:11 -0400] "GET //favicon.ico HTTP/1.1" 200 3426
        StringBuilder sb = new StringBuilder(line);
        String ip = munchTo(sb, " ");
        munchTo(sb, " "); //ignore -
        munchTo(sb, " ["); //ignore -, and eat the leading [
        String dateStr = munchTo(sb, "] \""); //]-space is intentional: eat both
        Date date = parseDate(dateStr);
        String request = munchTo(sb, "\" "); // quote-space is intentional: eat both
        String statusStr = munchTo(sb, " ");
        int status = Integer.parseInt(statusStr);
        String byteStr = munchTo(sb, " ");
        int bytes = Integer.parseInt(byteStr);
        return new LogEntry(ip, request, status, bytes, date);
    }
    public static Date parseDate(String dateStr) {
        ParsePosition pp = new ParsePosition(0);
        return  dateFormat.parse(dateStr, pp);
    }}
    
public class LogEntry {

    private static String ipAddress;
    private static String request;
    private static int statusCode;
    private static int bytesReturned;
    private static Date accessTime;

    public LogEntry(String ip, String req, int stCode, int bytes, Date accTime) {
        ipAddress = ip;
        request = req;
        statusCode = stCode;
        bytesReturned = bytes;
        accessTime = accTime;
    }

    public static String getIp() {
        return ipAddress;
    }

    public static String getRequest() {
        return request;
    }

    public static int getStatusCode() {
        return statusCode;
    }

    public static int getBytesReturned() {
        return bytesReturned;
    }

    public static Date getAccessTime() {
        return accessTime;
    }

    public String toString() {
        return ipAddress + " " + request + " " + statusCode + " " + accessTime + " " + bytesReturned;
    }

}

Answer 1

Each LogEntry is being printed, not just the last one. The problem is every LogEntry object share the one set of fields because the fields are static.

private static String ipAddress;
private static String request;
private static int statusCode;
private static int bytesReturned;
private static Date accessTime;

When a new instance is created, the field values are overwritten, so all the existing instances have their values set to the latest created instance.

Delete the static keyword:

private String ipAddress;
private String request;
private int statusCode;
private int bytesReturned;
private Date accessTime;