Java如何获取静态资源文件路径

public class ResourceTest {
    @Test
    public void test1() {
        // /Users/luojiacheng/code/translaction-test/target/test-classes/com/ljc/
        System.out.println(ResourceTest.class.getResource("").getPath());
        // /Users/luojiacheng/code/translaction-test/target/test-classes/
        System.out.println(ResourceTest.class.getResource("/").getPath());
        // /Users/luojiacheng/code/translaction-test/target/test-classes/
        System.out.println(ResourceTest.class.getClassLoader().getResource("").getPath());
        // null
        System.out.println(ResourceTest.class.getClassLoader().getResource("/"));
    }
}

public InputStream getResourceAsStream(String name) {
    URL url = getResource(name);
    try {
        return url != null ? url.openStream() : null;
    } catch (IOException e) {
        return null;
    }
}

public java.net.URL getResource(String name) {
    // 获取包路径
    name = resolveName(name);
    ClassLoader cl = getClassLoader0();
    if (cl==null) {
        // A system class.
        return ClassLoader.getSystemResource(name);
    }
  	// "" -> com/.../    "/" -> ""
    return cl.getResource(name);
}

    /**
     * 无内容返回
     */
    @GetMapping("/getTextFromFile")
    public String getTextFromFile() throws IOException {
        String filePath = MyFileOperation.class.getResource("/a.txt").getPath();
        // **.jar!/BOOT-INF/classes!/a.txt
        System.out.println(filePath);
        File file = new File(filePath);
        StringBuilder s = new StringBuilder();
        if (file.exists()) {
            InputStreamReader isr = new InputStreamReader(new FileInputStream(file), "gbk");
            BufferedReader bufferedReader = new BufferedReader(isr);
            String str;
            while ((str = bufferedReader.readLine()) != null) {
                s.append(str);
            }
        }
        return s.toString();
    }
    /**
     * 正确
     */
    @GetMapping("/getTextFromFileByStream")
    public String getTextFromFileByStream() throws IOException {
        StringBuilder s = new StringBuilder();
        InputStreamReader isr = new InputStreamReader( MyFileOperation.class.getResourceAsStream("/a.txt"), "gbk");
        BufferedReader bufferedReader = new BufferedReader(isr);
        String str;
        while ((str = bufferedReader.readLine()) != null) {
            s.append(str);
        }
        return s.toString();
    }