Order Statistics Processor

A multithreaded Java program for processing JSON files with Orders and generating statistics in XML format.

📋 Contents

• Description
• Basic entities
• File examples
• Available attributes
• Threads Performance Benchmark Summary
• Project architecture
• Installation and Run

Description

The program processes a set of JSON files with orders, collects statistics for the selected attribute, and generates an XML report, sorted from largest to smallest.

Features:

• ✅ Multithreaded file processing
• ✅ Support for 8 attributes for statistics
• ✅ Separation of tags by delimiters (, | ; #)
• ✅ Sorting results in descending order
• ✅ Thread-safe processing with ConcurrentHashMap
• ✅ Input data validation

Basic entities

1. Order

The main business entity of the system.

public class Order {
    private String id;
    private Customer customer;
    private String status;
    private String tags;
    private String paymentMethod;
    private double amount;
    private long createdAt;
}

2. Customer

Contains the customer's data.

public class Customer {
    private String id;
    private String fullName;
    private String email;
    private String phone;
    private String city;
}

3. StatisticItem

Represents a single statistics record.

public class StatisticItem {
    private String value;    // Attribute value (e.g., “Lviv”)
    private Integer count;   // Number of occurrences
}

4. StatisticsWrapper

The root element of an XML document.

@JacksonXmlRootElement(localName = "statistics")
public class StatisticsWrapper {
    @JacksonXmlElementWrapper(localName = "items")
    @JacksonXmlProperty(localName = "item")
    private List<StatisticItem> items;  // List of all statistical records
}

5. ApplicationConfig

Saves the program settings.

public class ApplicationConfig {
    private String inputDirectory;
    private String outputDirectory;
    private String attribute;
    private int threadPoolSize;
}

File examples

Input file (orders.json)

[
  {
    "id": "ord-001",
    "customer": {
      "id": "cust-101",
      "fullName": "Vasyl Cotop",
      "email": "vasyl@example.com",
      "phone": "+380501112233",
      "city": "Lviv"
    },
    "status": "NEW",
    "tags": "gift, urgent",
    "paymentMethod": "card",
    "amount": 499.99,
    "createdAt": 1731600000
  },
  {
    "id": "ord-002",
    "customer": {
      "id": "cust-102",
      "fullName": "Petro Poroh",
      "email": "petro@example.com",
      "phone": "+380501112233",
      "city": "Kyiv"
    },
    "status": "DONE",
    "tags": "gift",
    "paymentMethod": "card",
    "amount": 499.99,
    "createdAt": 1731600000
  },
  {
    "id": "ord-003",
    "customer": {
      "id": "cust-103",
      "fullName": "Zelya Boba",
      "email": "zelya@example.com",
      "phone": "+380501112233",
      "city": "Kyiv"
    },
    "status": "NEW",
    "tags": "gift, urgent, newCustomer",
    "paymentMethod": "card",
    "amount": 499.99,
    "createdAt": 1731600000
  }
]

Output file (statistics_by_city.xml)

<?xml version='1.0' encoding='UTF-8'?>
<statistics>
    <items>
        <item>
            <value>Kyiv</value>
            <count>2</count>
        </item>
        <item>
            <value>Lviv</value>
            <count>1</count>
        </item>
    </items>
</statistics>

Example of tag statistics (statistics_by_tags.xml)

<?xml version='1.0' encoding='UTF-8'?>
<statistics>
    <items>
        <item>
            <value>gift</value>
            <count>3</count>
        </item>
        <item>
            <value>urgent</value>
            <count>2</count>
        </item>
        <item>
            <value>newCustomer</value>
            <count>1</count>
        </item>
    </items>
</statistics>

Example of status statistics (statistics_by_status.xml)

<?xml version='1.0' encoding='UTF-8'?>
<statistics>
    <items>
        <item>
            <value>NEW</value>
            <count>2</count>
        </item>
        <item>
            <value>DONE</value>
            <count>1</count>
        </item>
    </items>
</statistics>

Available attributes

Attribute	Desc	Example
id	Customer ID	cust-101
status	Order status	NEW, DONE, CANCELED
tags	Tags (separated)	gift, urgent, promo
paymentMethod	Payment method	card, cash, PayPal
fullName	Customer fullName	Vasyl Cotop
email	Customer email	vasyl@example.com
phone	Customer phone	+380501112233
city	Customer city	Lviv

Threads Performance Benchmark Summary

Dataset Characteristics

The benchmark was executed on a synthetic dataset designed to simulate large-scale JSON processing:

• Files: 100 JSON files
• Records per file: 10,000
• Total records: 1,000,000
• Average file size: ~3.4 MB
• Total dataset size: ~340 MB
• Record structure: Each record represents an Order object containing nested Customer information. This structure includes multiple string fields, IDs, contact data, and nested objects, making it representative of real-world e-commerce/order-processing workloads.

Benchmark Summary

The following table presents the execution time, memory consumption, and speedup ratio for processing a large JSON dataset using different thread counts:

Threads	Time (s)	Mem (MB)	Speedup
1	3.462	99.904	1.00x
2	2.169	157.668	1.60x
4	1.587	155.025	2.18x
6	1.540	153.367	2.25x
8	1.591	130.650	2.18x

The highest speedup was achieved with 6 threads, after which performance began to plateau due to CPU saturation and increased thread contention.

Hardware Configuration

All benchmarks were executed on the following system configuration:

CPU:  AMD Ryzen 5 3550H
      Cores: 4
      Threads: 8
      Base Clock: 2.1 GHz
      Boost Clock: 3.7 GHz
      Cache: 2MB L2 + 4MB L3
MEM:  16GB DDR4-2400
DISK: NVMe SSD
OS:   Linux (kernel 5.x)
JVM:  OpenJDK 21

Project architecture

Main components

com.halmber
├── config
│   ├── ApplicationConfig         # Config
│   └── ConsoleInputHandler       # Console Input Handler
├── exception
│   └── InvalidAttributeException # Exception for Invalid Attributes
├── factory
│   └── statistics
│       ├── StatisticItemFactory          # Factory for StatisticItem
│       └── StatisticsWrapperFactory      # Factory for StatisticsWrapper
├── model
│   ├── Customer                  # Customer Model
│   ├── Order                     # Order Model
│   └── statistics
│       ├── StatisticItem         # Statistic Item
│       └── StatisticsWrapper     # XML Statistics Wrapper
└── service
    ├── FileService               # File Management Service
    ├── JsonFileReader            # JSON Reading
    ├── XmlFileWriter             # XML sorted Writing
    └── order
        ├── ProcessingService     # Multi-threaded Processing 
        ├── StatisticProcessor    # Statistic Processing
        └── StatisticsService     # Orchestrator

Data flow

Input JSON Files
       ↓
FileService (list files)
       ↓
ProcessingService (ExecutorService with N threads)
       ↓
JsonFileReader (parse JSON)
       ↓
StatisticProcessor (aggregate statistics)
       ↓
ConcurrentHashMap (thread-safe storage)
       ↓
XmlFileWriter (sort + serialize)
       ↓
Output XML File

Installation and Run

Requirements

• JDK 21+
• Maven 3.8+
• IntelliJ IDEA (optional, for running from IDE)

Run from IDE

You can also run the project directly from IntelliJ IDEA:

1. Open the project in IntelliJ IDEA.
2. Make sure the correct JDK (21+) is selected.
3. Open the Main class.
4. Right-click on the class → Run 'Main.main()'.

All dependencies are automatically resolved by the IDE.

Start project using Maven (with dependencies)

> mvn clean compile exec:java

This command compiles the project and runs it directly using Maven. All dependencies are automatically included.

Project build (jar without dependencies)

mvn clean package

Note: This JAR does not include dependencies, so it cannot be run with java -jar directly because project relies on external libraries.

Run (jar without dependencies)

java -jar target/java-core-profitsoft-internship-1.0-SNAPSHOT.jar

This will work only if a fat-jar is built, including external dependencies.

Interactive configuration

After launching the project, follow the instructions in the console.

====== Order Statistics Configuration ======

Available attributes: id | status | tags | paymentMethod | fullName | email | phone | city |
Enter input directory path (default: src/main/resources/):
Enter attribute name (default example: id): city
Enter threads pool size (default: 8): 8

Configuration set:
Input directory: src/main/resources/
Attribute: city
Output directory: src/main/resources/outputFiles
Threads count: 8

====== END Order Statistics Configuration END ======

Testing

mvn test

License

MIT License

Author

halmber