Java-读取resources下的文件方式

1. 不通用：使用项目内路径读取，该路径只在开发工具中显示，如：src/main/resources/resource.properties。只能在开发工具中使用，部署之后无法读取。（不通用）

public void read() throws IOException {
    File file = new File("src/main/resources/resource.properties");
    FileInputStream fis = new FileInputStream(file);
    InputStreamReader isr = new InputStreamReader(fis);
    BufferedReader br = new BufferedReader(isr);
    String data = null;
    while((data = br.readLine()) != null) {
        System.out.println(data);
    }
    br.close();
    isr.close();
    fis.close();
}

2. 不通用：使用org.springframework.util.ResourceUtils读取，在linux环境中无法读取。（不通用）

public void read2() throws IOException {
    File file = ResourceUtils.getFile("classpath:resource.properties");
    FileInputStream fis = new FileInputStream(file);
    InputStreamReader isr = new InputStreamReader(fis);
    BufferedReader br = new BufferedReader(isr);
    String data = null;
    while((data = br.readLine()) != null) {
        System.out.println(data);
    }
    br.close();
    isr.close();
    fis.close();
}

3. 使用org.springframework.core.io.ClassPathResource, 各环境都能读取。（通用）

public void testReadFile() throws IOException {
    //  ClassPathResource classPathResource = new ClassPathResource("resource.properties");
    Resource resource = new ClassPathResource("resource.properties");
    InputStream is = resource.getInputStream();
    InputStreamReader isr = new InputStreamReader(is);
    BufferedReader br = new BufferedReader(isr);
    String data = null;
    while((data = br.readLine()) != null) {
        System.out.println(data);
    }
    br.close();
    isr.close();
    is.close();
}