复制文件的异常处理（四种）

package com.czie.iot1913.lps.IO.BufferStream.Better;

import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

/**
 * FileName: CopyFileDemo01
 * Author:   lps
 * Date:     2022/3/27 15:30
 * Sign:刘品水 Q：1944900433
 */
public class CopyFileDemo01 {
    public static void main(String[] args) {

    }
    //JDK9改进方案 我是JDK8无法运行就了解下
//    private static void methodJDK9() throws IOException {
//        FileReader fr = new FileReader("fr.txt");
//        FileWriter fw = new FileWriter("fw.txt");
//        try(fr,fw) {
//            char[] chs = new char[1024];
//            int len;
//            while((len= fr.read(chs))!=-1){
//                fw.write(chs,0,len);
//            }
//        }catch (IOException e){
//            e.printStackTrace();
//        }
//
//    }

    //JDK7改进方案
    private static void methodJDK7() {
        try (FileReader fr = new FileReader("fr.txt");
             FileWriter fw = new FileWriter("fw.txt");){
            char[] chs = new char[1024];
            int len;
            while((len= fr.read(chs))!=-1){
                fw.write(chs,0,len);
            }

        }catch (IOException e){
            e.printStackTrace();
        }

    }

    //try..catch..finally
    private static void method2()  {
        FileReader fr=null;
        FileWriter fw=null;
        try {
            fr = new FileReader("fr.txt");
            fw = new FileWriter("fw.txt");

            char[] chs = new char[1024];
            int len;
            while((len= fr.read(chs))!=-1){
                fw.write(chs,0,len);
            }

        }catch (IOException e){
            e.printStackTrace();
        }finally {
            if (fw!=null){
                try {
                    fw.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fr!=null){
                try {
                    fr.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

        }

    }

    private static void method() throws IOException {
        FileReader fr = new FileReader("fr.txt");
        FileWriter fw = new FileWriter("fw.txt");

        char[] chs = new char[1024];
        int len;
        while((len= fr.read(chs))!=-1){
            fw.write(chs,0,len);
        }
        fw.close();
        fr.close();
    }
}