高效 告别996，开启java高效编程之门 4-3传统方式关闭流资源

package com.imooc.zhangxiaoxi.resource;

import org.junit.Test;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

/**
 * FileCopyTest
 *
 * @author 魏豆豆
 * @date 2020/5/24
 */
public class FileCopyTest {

    //标准做法
    /**
     * demo
     * 1    创建输入流/输出流
     * 2    文件写入
     * 3    物理流资源关闭
     */
    @Test
    public void copyTestOriginal(){
        //1    创建输入流/输出流
        String fileInputStreamUrl = "lib2/FileCopyTest.java";
        String fileOutputStreamUrl = "targetTest/target.txt";

        FileInputStream fileInputStream = null;
        FileOutputStream fileOutputStream = null;

        try {
            fileInputStream = new FileInputStream(fileInputStreamUrl);
            fileOutputStream = new FileOutputStream(fileOutputStreamUrl);

            //读取的字节信息
            int content;
            //迭代，读取/写入字节  未到达文尾的部分读取后放到新的文件中
            while ((content=fileInputStream.read())!=-1){
                fileOutputStream.write(content);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            //3    物理流资源关闭
            if (fileOutputStream != null) {
                try {
                    fileOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fileInputStream != null) {
                try {
                    fileInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }




   //自己做的错误的
    /**
     * demo
     * 1    创建输入流/输出流
     * 2    文件写入
     * 3    物理流资源关闭
     */
    @Test
    public void copyTest(){
        //1    创建输入流/输出流
        FileInputStream fileInputStream = null;
        FileOutputStream fileOutputStream = null;

        //2    文件写入
        int content = 0;
        try {
            if((content=fileInputStream.read())!=-1){
                fileOutputStream.write(content);
                content++;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        //3    物理流资源关闭
        if(fileOutputStream!=null){
            try {
                fileOutputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if(fileInputStream!=null){
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}