Java Memory Management Process | Dataford Interview Questions

Your question is Java Memory Management Process. Take a moment with it on the right.

Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).

Problem

Relevance Lab's automation platform keeps a cache of recent test-run logs in memory for quick QA dashboard access. Here's the class responsible for it.

import java.util.*;
import java.io.*;

public class TestRunLogger {
    private static List<String> allLogs = new ArrayList<>();

    public void logRun(String testId, String result) {
        String entry = testId + ":" + result;
        allLogs.add(entry);

        try {
            FileWriter fw = new FileWriter("run_history.log", true);
            fw.write(entry + "
");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public String buildReport() {
        String report = "";
        for (String log : allLogs) {
            report = report + log + "
";
        }
        return report;
    }
}

What would the memory management process be for this code in Java? Walk through what happens as logRun is called repeatedly over a long-running test session, and what you'd change.

Your question is Java Memory Management Process. Take a moment with it on the right.

Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).

Relevance Lab's automation platform keeps a cache of recent test-run logs in memory for quick QA dashboard access. Here's the class responsible for it.

import java.util.*;
import java.io.*;

public class TestRunLogger {
    private static List<String> allLogs = new ArrayList<>();

    public void logRun(String testId, String result) {
        String entry = testId + ":" + result;
        allLogs.add(entry);

        try {
            FileWriter fw = new FileWriter("run_history.log", true);
            fw.write(entry + "
");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public String buildReport() {
        String report = "";
        for (String log : allLogs) {
            report = report + log + "
";
        }
        return report;
    }
}

What would the memory management process be for this code in Java? Walk through what happens as logRun is called repeatedly over a long-running test session, and what you'd change.