In this tutorial, we will show you how to read a file from a resources folder or classpath, in both runtime and unit test environment. Try putting a file into the src/main/resources folder, and read the file with following code snippets :

1. getResource

	File file = new File(
		getClass().getClassLoader().getResource("database.properties").getFile()
	);

2. getResourceAsStream

	InputStream inputStream = getClass()
			.getClassLoader().getResourceAsStream("database.properties");

1. Project Directory

Review a Maven project Structure.

2. Read file from resources folder

datasource.url=jdbc:mysql://localhost/mkyong?useSSL=false
datasource.username=root
datasource.password=password
datasource.driver-class-name=com.mysql.jdbc.Driver

Read database.properties file and print out the content.

package com.mkyong;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.URL;
public class Application {
    public static void main(String[] args) throws IOException {
        Application main = new Application();
        File file = main.getFileFromResources("database.properties");
        printFile(file);
    // get file from classpath, resources folder
    private File getFileFromResources(String fileName) {
        ClassLoader classLoader = getClass().getClassLoader();
        URL resource = classLoader.getResource(fileName);
        if (resource == null) {
            throw new IllegalArgumentException("file is not found!");
        } else {
            return new File(resource.getFile());
    private static void printFile(File file) throws IOException {
        if (file == null) return;
        try (FileReader reader = new FileReader(file);
             BufferedReader br = new BufferedReader(reader)) {
            String line;
            while ((line = br.readLine()) != null) {
                System.out.println(line);

Output

datasource.url=jdbc:mysql://localhost/mkyong?useSSL=false
datasource.username=root
datasource.password=password
datasource.driver-class-name=com.mysql.jdbc.Driver

3. Unit Test

<test>
    <case id='1'>
        <param>100</param>
        <expected>mkyong</expected>
    </case>
    <case id='2'>
        <param>99</param>
        <expected>mkyong</expected>
    </case>
</test>

Read data.xml and print out the content.

package com.mkyong;
import org.apache.commons.io.IOUtils;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
public class ApplicationTest {
    @DisplayName("Test loading XML")
    @Test
    void loadXMLTest() {
        ClassLoader classLoader = getClass().getClassLoader();
        try (InputStream inputStream = classLoader.getResourceAsStream("xml/data.xml")) {
            String result = IOUtils.toString(inputStream, StandardCharsets.UTF_8);
            System.out.println(result);
        } catch (IOException e) {
            e.printStackTrace();

Output

<test>
    <case id='1'>
        <param>100</param>
        <expected>mkyong</expected>
    </case>
    <case id='2'>
        <param>99</param>
        <expected>mkyong</expected>
    </case>
</test>

	<dependencies>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>5.4.2</version>
            <scope>test</scope>
        </dependency>
    </dependencies>