java1.7新特性:try-with-resources

转载：https://blog.csdn.net/fanxiaobin577328725/article/details/53067163

首先看代码：

import org.junit.Test;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;

public class TryWithResources {

    @Test
    public void test() throws FileNotFoundException {

        FileInputStream inputStream1 = new FileInputStream("e:\\ipscan.txt");
        InputStreamReader reader1 = new InputStreamReader(inputStream1);
        BufferedReader br1 = new BufferedReader(reader1);

        FileInputStream inputStream2 = new FileInputStream("g:\\sample.txt");
        InputStreamReader reader2 = new InputStreamReader(inputStream2);

        BufferedReader br2 = new BufferedReader(reader2);

        try(BufferedReader b3 = new BufferedReader(reader2);BufferedReader b4 = new BufferedReader(reader1))
        {
            System.out.println(br1.readLine()+br2.readLine());
        }catch (Exception e)
        {
            System.err.println(e);
        }

        //JAVA9才支持
//        try(br1;br2)
//        {
//            System.out.println(br1.readLine()+br2.readLine());
//        }catch (Exception e)
//        {
//            System.err.println(e);
//        }
    }
}

使用前置条件：实现java.lang.AutoCloseable接口

java1.7引入的新特性。类似于C#的using语句块，只要类实现了IDisposable接口