JDK7及其之后的资源关闭方式

public static void main(String[] args) {
    FileInputStream inputStream = null;
    try {
        inputStream = new FileInputStream(new File("test"));
        System.out.println(inputStream.read());
    } catch (IOException e) {
        throw new RuntimeException(e.getMessage(), e);
    } finally {
        if (inputStream != null) {
            try {
                inputStream.close();
            } catch (IOException e) {
                throw new RuntimeException(e.getMessage(), e);
            }
        }
    }
}
public static void main(String[] args) {
    try (FileInputStream inputStream = new FileInputStream(new File("test"))) {
        System.out.println(inputStream.read());
    } catch (IOException e) {
        throw new RuntimeException(e.getMessage(), e);
    }
}

1、当一个外部资源的句柄对象实现了AutoCloseable接口,JDK7中便可以利用try-with-resource语法更优雅的关闭资源,消除板式代码。
2、try-with-resource时,如果对外部资源的处理和对外部资源的关闭均遭遇了异常,“关闭异常”将被抑制,“处理异常”将被抛出,但“关闭异常”并没有丢失,而是存放在“处理异常”的被抑制的异常列表中。