/**
     * 方法一：使用類加載器的getResource().getPath()獲取全路徑再拼接文件名，最后根據(jù)文件路徑獲取文件流
     * 備注：jar包不可用，因為jar包中沒有一個實(shí)際的路徑存放文件
     *
     * @param fileName
     * @return
     * @throws FileNotFoundException
     */
    public BufferedReader function1(String fileName) throws FileNotFoundException {

        //   /Users/zunf/code/read-resource/target/classes/
        String path = this.getClass().getClassLoader().getResource("").getPath();
        //   /Users/zunf/code/read-resource/target/classes/測試.txt
        String filePath = path + fileName;

        return new BufferedReader(new FileReader(filePath));
    }

    /**
     * 方法二：使用類加載器的getResource().getPath()，傳參直接獲取文件路徑，再根據(jù)文件路徑獲取文件流
     * 備注：jar包不可用，因為jar包中沒有一個實(shí)際的路徑存放文件
     *
     * @param fileName
     * @return
     * @throws IOException
     */
    public BufferedReader function2(String fileName) throws IOException {

        //   /Users/zunf/code/read-resource/target/classes/%e6%b5%8b%e8%af%95.txt
        String filePath = this.getClass().getClassLoader().getResource(fileName).getPath();

        //可以看到上面讀取到路徑的中文被URLEncoder編碼了，所以需要先用URLDecoder解碼一下，恢復(fù)中文
        filePath = URLDecoder.decode(filePath, "UTF-8");

        return new BufferedReader(new FileReader(filePath));
    }

    /**
     * 方法三：使用類加載器的getResourceAsStream()，直接獲取文件流
     * 備注：jar包可用
     *
     * @param fileName
     * @return
     * @throws IOException
     */
    public BufferedReader function3(String fileName) throws IOException {
        //getResourceAsStream(fileName) 等價于getResource(fileName).openStream()
        InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream(fileName);
        if (inputStream == null) {
            throw new FileNotFoundException(fileName);
        }
        return new BufferedReader(new InputStreamReader(inputStream));
    }

    /**
     * 方法四：使用Class對象的getResourceAsStream()獲取文件流
     * 備注：jar包可用
     *
     * @param fileName
     * @return
     * @throws IOException
     */
    public BufferedReader function4(String fileName) throws IOException {
        //getResourceAsStream(fileName) 等價于getResource(fileName).openStream()
        InputStream inputStream = this.getClass().getResourceAsStream("/" + fileName);
        if (inputStream == null) {
            throw new FileNotFoundException(fileName);
        }
        return new BufferedReader(new InputStreamReader(inputStream));
    }

    /**
     * 方法五：使用Spring提供的ClassPathResource獲取
     * 備注：jar包可用
     *
     * @param fileName
     * @return
     * @throws IOException
     */
    public BufferedReader function5(String fileName) throws IOException {
        ClassPathResource classPathResource = new ClassPathResource(fileName);
        InputStream inputStream = classPathResource.getInputStream();
        return new BufferedReader(new InputStreamReader(inputStream));
    }

    /**
     * 方法六：使用Hutool的ResourceUtil
     * 備注：jar包可用
     *
     * @param fileName
     * @return
     * @throws IOException
     */
    public BufferedReader function6(String fileName) throws IOException {
        List<URL> resources = ResourceUtil.getResources(fileName);
        URL resource = resources.get(0);
        return new BufferedReader(new InputStreamReader(resource.openStream()));
    }

   //Jar包啟動時根據(jù)傳入的不同funcation值來選擇調(diào)用哪個方法測試
    @Value("${function}")
    private int function;    


    @GetMapping("/test")
    public String test() throws IOException {
        //需要在resource里讀取的文件
        String fileName = "測試.txt";

        //調(diào)用方法
        System.out.println("調(diào)用function" + function);
        BufferedReader bufferedReader = null;
        switch (function) {
            case 1:
                bufferedReader = function1(fileName);
                break;
            case 2:
                bufferedReader = function2(fileName);
                break;
            case 3:
                bufferedReader = function3(fileName);
                break;
            case 4:
                bufferedReader = function4(fileName);
                break;
            case 5:
                bufferedReader = function5(fileName);
                break;
            case 6:
                bufferedReader = function6(fileName);
                break;
            default:
        }

        //讀取并輸出
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = bufferedReader.readLine()) != null) {
            sb.append(line).append("\n");
        }
        System.out.println(sb);
        return sb.toString();
    }