如何使用config.property文件将任何类型的文件（例如txt文件）写入资源文件夹，但不使用Java中的绝对路径文件

Question

How to write or read any type of file (for example .txt file) to a resources folder with the config.property file, but without using absolute path file.

I tried to solve this like below:

ClassLoader classLoader = Setting.class.getClassLoader();
Setting setting = new Setting();

try (InputStream resourceAsStream = classLoader.getResourceAsStream("config.properties")) {
   setting.load(resourceAsStream);
}

String readFileName = setting.getValue("pathSource.txt");
String writeFileName = setting.getValue("outPutPathSourceFile.txt");

String s = System.getProperty("line.separator");

File readFile = new File("./src/main/resources" + File.separator + "pathSource.txt");
File writeFile = new File("./src/main/resources" + File.separator + "outPutPathSourceFile.txt");

However, I don't want using ./src/main/resources prefix.

Answer 1

If your file is located under resources you able to access it like:

File file = new File(classLoader.getResource(fileName).getFile());

if you are using Spring you can use ResourceUtils.getFile() :

File file = ResourceUtils.getFile("classpath:fileName")

UPDATE:

If I understand correctly, you want to read file which located under your src/main/resources without relative path usage /src/main/resources .

I created small demo:

public class ReadResourceFile {
    public static void main(String[] args) throws IOException {
        String fileName = "webAutomationConfig.xml";
        ClassLoader classLoader = ReadResourceFile.class.getClassLoader();
        File file = new File(classLoader.getResource(fileName).getFile());

        System.out.println("File exists: " + file.exists());

        String content = new String(Files.readAllBytes(file.toPath()));
        System.out.println(content);
    }
}

Output:

File exists: true
<?xml version="1.0" encoding="utf-8"?>
<config>
    <baseUrl>https://www.gmail.com</baseUrl>
</config>

Project structure:

Answer 2

Resources (files on the class path, possibly inside a jar)can be read, but are not intended to be written to. You can use them as template to create an inital copy on the file system. – Joop Eggen