public static void main(String[] args) throws Exception {
    FileWriter fw = null;
    try {
        fw = new FileWriter("xhh.txt");
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (fw != null) {
            try {
                fw.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

try (创建流对象语句，如果多个,使用';'隔开) {
    代码
} catch(IOException e){
    e.printStackTrace();
}

public static void main(String[] args) throws Exception {
    //该语句确保了每个资源在语句结束时关闭
    try (FileWriter fw = new FileWriter("xhh.txt");
         FileReader fr = new FileReader("xhh.txt")) {
        fw.write("xhh.com");
        int read = fr.read();
    } catch (IOException e) {
        e.printStackTrace();
    }
}