Try-with-resource
try-with-resources语句是一种声明了一种或多种资源的try语句。资源是指在程序用完了之后必须要关闭的对象。try-with-resources语句保证了每个声明了的资源在语句结束的时候都会被关闭。任何实现了java.lang.AutoCloseable接口的对象,和实现了java.io.Closeable接口的对象,都可以当做资源使用。
@Test
public void readFirstLineFromFile() throws IOException {
try (BufferedReader br =
new BufferedReader(new FileReader("D:\\tmp\\columnInfo_tmp.xls"))) {
assert br.readLine() != null;
}
}
等价于
@Test
public void readFirstLineFromFileWithFinallyBlock () throws IOException {
BufferedReader br = new BufferedReader(new FileReader("D:\\tmp\\columnInfo_tmp.xls"));
try {
assert br.readLine() != null;
} finally {
br.close();
}
}