FileInputStream和FileOutputStream的使用实例

package io;

import org.junit.Test;

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

public class StreamDemoTest {
    private String path0 = System.getProperty("user.dir") + "/src/main/resources/copy0.txt";
    private String path = System.getProperty("user.dir") + "/src/main/resources/d.txt";
    private File file = null;
    private FileInputStream fis = null;
    private FileOutputStream fos = null;

    @Test
    public void fun() throws Exception {
        FileInputStream fis = new FileInputStream(new File(this.getClass().getResource("/a.txt").getPath()));
        int i = 0;
        int i2 = 0;
        int i3 = 0;
        while ((i = fis.read()) != -1) {
            /*System.out.println((char)i);*/
            if (!(i >= 0 && i < 128)) {
                i2 = fis.read();
                i3 = fis.read();
                //UTF-8编码的情况，一个汉字占用3个字节
                System.out.println(new String(new byte[]{(byte) i, (byte) i2, (byte) i3}));
                //GBK编码的情况，一个汉字占用2个字节
                /*System.out.println(new String(new byte[]{(byte) i, (byte) i2}));*/
                continue;
            }
            System.out.println((char) i);
        }
        fis.close();
    }

    @Test
    public void fun2() throws Exception {
        File file = new File(path);
        if (!file.exists()) {
            file.createNewFile();
            fileOutputStreamFun();
        } else {
            fileOutputStreamFun();
        }
    }

    public void fileOutputStreamFun() {
        try {
            fos = new FileOutputStream(file);
            String a = "虎哥明天买车";
            fos.write(a.getBytes());
            fos.flush();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Test
    public void copy0() throws Exception {
        fis = new FileInputStream(new File("C:\Users\15082157\Desktop\自我介绍.txt"));
        fos = new FileOutputStream(path0);
        File file = new File(path0);
        if (!file.exists()) {
            file.createNewFile();
            fileOutputStreamCopy1();
        } else {
            fileOutputStreamCopy1();
        }
    }

    @Test
    public void copy() throws Exception {
        String path1 = System.getProperty("user.dir") + "/src/main/resources/copy.mp4";
        fis = new FileInputStream(new File("C:\Users\15082157\Desktop\3-4视频19秒.mp4"));
        fos = new FileOutputStream(path1);
        File file = new File(path1);
        if (!file.exists()) {
            file.createNewFile();
            /*fileOutputStreamCopy();*/
            fileOutputStreamCopy1();
        } else {
            /*fileOutputStreamCopy();*/
            fileOutputStreamCopy1();
        }
    }

    public void fileOutputStreamCopy() {
        int i = 0;
        int i2 = 0;
        int i3 = 0;
        byte hanZi[];
        try {
            long beginTime = getCurrentTime1();
            while ((i = fis.read()) != -1) {
                if (!(i >= 0 && i < 128)) {
                    i2 = fis.read();
                    i3 = fis.read();
                    hanZi = new byte[]{(byte) i, (byte) i2, (byte) i3};
                    fos.write(hanZi);
                    continue;
                }
                fos.write(i);
            }
            fos.flush();
            long endTime = getCurrentTime1();
            float time = (endTime - beginTime) / 1000F;
            System.out.println("copy时间为" + time + "s");
            fis.close();
            fos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void fileOutputStreamCopy1(){
        int len =0;
        byte[] bytes = new byte[1024]; // 创建一个长度是1024的byte类型的数组，用于存储读取到的数据
        try{
            long beginTime = getCurrentTime1();
            while ((len=fis.read(bytes))!=-1){
                fos.write(bytes);
            }
            fos.flush();
            long endTime = getCurrentTime1();
            float time = (endTime - beginTime) / 1000F;
            System.out.println("copy时间为" + time + "s");
            fis.close();
            fos.close();
        }catch (Exception e){
            e.printStackTrace();
        }
    }


    public long getCurrentTime1() {
        long currentTime = System.currentTimeMillis();
        System.out.println(currentTime);
        return currentTime;
    }
}

package io;

import org.junit.Test;

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

public class StreamDemoTest {
    private String path0 = System.getProperty("user.dir") + "/src/main/resources/copy0.txt";
    private String path = System.getProperty("user.dir") + "/src/main/resources/d.txt";
    private File file = null;
    private FileInputStream fis = null;
    private FileOutputStream fos = null;

@Test
public void fun() throws Exception {
        FileInputStream fis = new FileInputStream(new File(this.getClass().getResource("/a.txt").getPath()));
        int i = 0;
        int i2 = 0;
        int i3 = 0;
        while ((i = fis.read()) != -1) {
            /*System.out.println((char)i);*/
if (!(i >= 0 && i < 128)) {
                i2 = fis.read();
i3 = fis.read();
//UTF-8编码的情况，一个汉字占用3个字节
System.out.println(new String(new byte[]{(byte) i, (byte) i2, (byte) i3}));
//GBK编码的情况，一个汉字占用2个字节
/*System.out.println(new String(new byte[]{(byte) i, (byte) i2}));*/
continue;
}
            System.out.println((char) i);
}
        fis.close();
}

    @Test
public void fun2() throws Exception {
        File file = new File(path);
        if (!file.exists()) {
            file.createNewFile();
fileOutputStreamFun();
} else {
            fileOutputStreamFun();
}
    }

    public void fileOutputStreamFun() {
        try {
            fos = new FileOutputStream(file);
String a = "虎哥明天买车";
fos.write(a.getBytes());
fos.flush();
fos.close();
} catch (IOException e) {
            e.printStackTrace();
}
    }

    @Test
public void copy0() throws Exception {
        fis = new FileInputStream(new File("C:\Users\15082157\Desktop\自我介绍.txt"));
fos = new FileOutputStream(path0);
File file = new File(path0);
        if (!file.exists()) {
            file.createNewFile();
fileOutputStreamCopy1();
} else {
            fileOutputStreamCopy1();
}
    }

    @Test
public void copy() throws Exception {
        String path1 = System.getProperty("user.dir") + "/src/main/resources/copy.mp4";
fis = new FileInputStream(new File("C:\Users\15082157\Desktop\3-4视频19秒.mp4"));
fos = new FileOutputStream(path1);
File file = new File(path1);
        if (!file.exists()) {
            file.createNewFile();
/*fileOutputStreamCopy();*/
fileOutputStreamCopy1();
} else {
            /*fileOutputStreamCopy();*/
fileOutputStreamCopy1();
}
    }

    public void fileOutputStreamCopy() {
        int i = 0;
        int i2 = 0;
        int i3 = 0;
        byte hanZi[];
        try {
            long beginTime = getCurrentTime1();
            while ((i = fis.read()) != -1) {
                if (!(i >= 0 && i < 128)) {
                    i2 = fis.read();
i3 = fis.read();
hanZi = new byte[]{(byte) i, (byte) i2, (byte) i3};
fos.write(hanZi);
                    continue;
}
                fos.write(i);
}
            fos.flush();
            long endTime = getCurrentTime1();
            float time = (endTime - beginTime) / 1000F;
System.out.println("copy时间为" + time + "s");
fis.close();
fos.close();
} catch (Exception e) {
            e.printStackTrace();
}
    }

    public void fileOutputStreamCopy1(){
        int len =0;
        byte[] bytes = new byte[1024]; // 创建一个长度是1024的byte类型的数组，用于存储读取到的数据
try{
            long beginTime = getCurrentTime1();
            while ((len=fis.read(bytes))!=-1){
                fos.write(bytes);
}
            fos.flush();
            long endTime = getCurrentTime1();
            float time = (endTime - beginTime) / 1000F;
System.out.println("copy时间为" + time + "s");
fis.close();
fos.close();
}catch (Exception e){
            e.printStackTrace();
}
    }


    public long getCurrentTime1() {
        long currentTime = System.currentTimeMillis();
System.out.println(currentTime);
        return currentTime;
}
}