package test;

import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try {
            String fileContent = getFileFromResources("resourcesFile.txt");
            System.out.println(fileContent);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //USE THIS FUNCTION TO READ CONTENT OF A FILE, IT MUST EXIST IN "RESOURCES" FOLDER
    public static String getFileFromResources(String fileName) throws Exception {
        ClassLoader classLoader = Main.class.getClassLoader();
        InputStream stream = classLoader.getResourceAsStream(fileName);
        String text = null;
        try (Scanner scanner = new Scanner(stream, StandardCharsets.UTF_8.name())) {
            text = scanner.useDelimiter("\\A").next();
        }
        return text;
    }
}

你可以使用旧的Stupid Scanner技巧在线程序来做到这一点，而不需要任何额外的依赖，如番石榴:

String text = new Scanner(AppropriateClass.class.getResourceAsStream("foo.txt"), "UTF-8").useDelimiter("\\A").next();

伙计们，除非你真的需要，否则不要用第三方的东西。JDK中已经有很多功能了。

Guava有一个“toString”方法用于将文件读入String:

import com.google.common.base.Charsets;
import com.google.common.io.Files;

String content = Files.toString(new File("/home/x1/text.log"), Charsets.UTF_8);

这个方法不需要文件在类路径中(就像Jon Skeet之前的回答一样)。

至少在Apache common -io 2.5中，IOUtils.toString()方法支持URI参数，并返回位于类路径上的jar中的文件内容:

IOUtils.toString(SomeClass.class.getResource(...).toURI(), ...)

如果你有番石榴，那么你可以使用:

String fileContent = Files.asCharSource(new File(filename), Charset.forName("UTF-8")).read();

(其他解决方案提到了番石榴的其他方法，但已弃用)

package test;

import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try {
            String fileContent = getFileFromResources("resourcesFile.txt");
            System.out.println(fileContent);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //USE THIS FUNCTION TO READ CONTENT OF A FILE, IT MUST EXIST IN "RESOURCES" FOLDER
    public static String getFileFromResources(String fileName) throws Exception {
        ClassLoader classLoader = Main.class.getClassLoader();
        InputStream stream = classLoader.getResourceAsStream(fileName);
        String text = null;
        try (Scanner scanner = new Scanner(stream, StandardCharsets.UTF_8.name())) {
            text = scanner.useDelimiter("\\A").next();
        }
        return text;
    }
}