- 使用面向对象方式统计文件夹大小
package com.yf.cn.app.io;
import java.io.File;
/**
* 使用面向对象: 统计文件夹的大小
* @author 裴新
*
*/
public class DirCount {
//大小
private long len;
//文件夹路径
private String path;
//文件的个数
private int fileSize;
//文件夹的个数
private int dirSize;
//源
private File src;
public DirCount(String path) {
this.path = path;
this.src = new File(path);
count(this.src);
}
//统计大小
private void count(File src) {
//获取大小
if(null!=src && src.exists()) {
if(src.isFile()) {
//大小
len+=src.length();
this.fileSize++;
}else {
//子孙级
this.dirSize++;
for(File s:src.listFiles()) {
count(s);
}
}
}
}
public long getLen() {
return len;
}
public int getFileSize() {
return fileSize;
}
public int getDirSize() {
return dirSize;
}
public static void main(String[] args) {
DirCount dir = new DirCount("D:/spb11");
System.out.println(dir.getLen()+"-->"+dir.getFileSize()+"-->"+dir.getDirSize());
DirCount dir2 = new DirCount("H:/linux运维/01-第1阶段-运维基本功/day01-运维概述与Linux系统安装");
System.out.println(dir2.getLen()+"-->"+dir2.getFileSize()+"-->"+dir2.getDirSize());
}
}
- File 字符集乱码处理方式
2.1编码和解码概念
2.2编码
2.3字节读取
package com.yf.cn.app.test;
import java.io.UnsupportedEncodingException;
/**
* @author yangfeng
* @version 1.0
* @date 2022-09-13 14:26
*/
public class ContentEncode {
public static void main(String[] args) throws UnsupportedEncodingException {
String msg = "性命生命使命a";
byte[] bytes = msg.getBytes();//默认使用工程字符集
System.out.println(bytes.length);
//编码为其他字符集
bytes = msg.getBytes("UTF-16LE");
System.out.println(bytes.length);
bytes = msg.getBytes("GBK");
System.out.println(bytes.length);
}
}
2.3解码
package com.yf.cn.app.test;
import java.io.UnsupportedEncodingException;
/**
* @author yangfeng
* @version 1.0
* @date 2022-09-13 14:26
*/
public class ContentDecode {
public static void main(String[] args) throws UnsupportedEncodingException {
String msg = "性命生命使命a";
byte[] bytes = msg.getBytes();//默认使用工程字符集
msg = new String(bytes);
System.out.println(msg);
/***
* @describe 乱码；
* 原因：1.字节数不够 2字符集不统一
* @author yangfeng
* @date 2022-09-13 14:38:52
* @param args
* @return
**/
msg = new String(bytes,0,bytes.length,"utf-8");
System.out.println(msg);
System.out.println("----字节数不够---");
msg = new String(bytes,0,bytes.length-2,"utf-8");
System.out.println(msg);
System.out.println("----字符集不符---");
msg = new String(bytes,0,bytes.length-2,"gbk");
System.out.println(msg);
}
}
- 文件拷贝
package com.yf.cn.app.io;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* @author yangfeng
* @version 1.0
* @date 2022-09-14 14:18
*/
public class FileCopy {
public static void main(String[] args) {
copy("D:/images/framework.PNG","D:/images/jiagou.png");
}
public static void copy(String sourcePath,String destPath){
//源
File src = new File(sourcePath);
//目标文件
File dp = new File(destPath);
InputStream is = null;
OutputStream os = null;
try {
//2.选择流
is = new FileInputStream(src);
os = new FileOutputStream(dp);
byte[] bytes = new byte[1024];
int len = -1;
while((len=is.read(bytes))!=-1){
//按照读出的字节大小进行写入
os.write(bytes,0,len);
}
//输出流刷新
os.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
//释放资源，分别关闭输入流和输出流，先打开的后关闭
try {
if(null!=os){
os.close();
}
} catch (IOException e) {
e.printStackTrace();
}
//释放输入流
try {
if(null!=is){
is.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
- 字符流操作
5.1输入字符流操作
package com.yf.cn.app.io;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
/**
* IO 流操作步骤
* 1.创建源
* 2.选择流
* 3.操作
* 4.释放资源
* @author yangfeng
* @version 1.0
* @date 2022-09-13 15:39
*/
public class FileReaderTest {
public static void main(String[] args) {
File file = new File("test.txt");
Reader reader = null;
try {
reader = new FileReader(file);
char[] chars = new char[1024];
int len = -1;
if((len=reader.read(chars))!=-1){
System.out.println(chars);
}
reader.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
5.2输出字符流操作
package com.yf.cn.app.io;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
/**
* IO 流操作步骤
* 1.创建源
* 2.选择流
* 3.操作
* 4.释放资源
* @author yangfeng
* @version 1.0
* @date 2022-09-13 15:39
*/
public class FileWriterTest {
public static void main(String[] args) {
File file = new File("readme.txt");
Writer writer = null;
try {
writer = new FileWriter(file,true);
String msg = "低调是一种美德";
writer.write(msg);
writer.flush();
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
if(null!=writer){
writer.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
- 节点流
6.1节点流定义
直接用来访问数据源（文件、内存、管道）的流，一般以File和Byte开头的流均为节点流
6.2架构图
