springboot讀取classpath目錄下文件

假設靜態資源文件 information.txt 放在 src/main/resources 目錄下

 public String getInfo() {
        String msg = "";
        InputStreamReader intput = null;
        try {
            Resource resource = new ClassPathResource("information.txt");
            File file = resource.getFile();
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
            msg = reader.readLine();
        } catch (Exception e) {
            log.error(e.getMessage());
        }
    return msg;
}

注意：

如果將該項目打包運行在Linux系統下，該方法無法讀取文件，報錯信息爲cannot be resolved to absolute file path because it does not reside in the file system。這是因爲在Linux系統下，spring無法訪問jar中的路徑。

解決方法：

使用ClassPathResource類的getInputStream方法獲取InputStream

Linux讀取resources目錄下文件：

 public String getInfo() {
        String msg = "";
        InputStreamReader intput = null;
        try {
            Resource resource = new ClassPathResource("information.txt");
            // 修改部分
            intput = new InputStreamReader(resource.getInputStream());		
            BufferedReader reader = new BufferedReader(intput);
            msg=  reader.readLine();
        } catch (Exception e) {
            log.error(e.getMessage());
        }
    return msg;
}