File是java.io包下的类，代表与平台无关的文件和目录
public static void main(String[] args) {
File dir = new File("D:/DXL/DXL5/A");
File[] files=dir.listFiles();
files=dir.listFiles(new FileFilter() {
@Override
public boolean accept(File pathname) {
System.out.println(pathname+" sdad");
return true;
}
});
System.out.println("========================================================================================================");
files=dir.listFiles(new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
System.out.println(dir + " " + name);
if (name.endsWith("f")){
return false;
}
return true;
}
});
System.out.println(Arrays.toString(files));
}
public static void main(String[] args) {
printFile("C:\\eSupport",0);
}
public static void printFile(String filePath,int depth){
File file = new File(filePath);
if (!file.exists()){
throw new IllegalArgumentException("文件不存在");
}
// 打印空格
for (int i = 0; i < depth; i++) {
System.out.print(" ");
}
// 打印名字
if (file.isFile()){
System.out.print(" - ");
}
System.out.println(file.getName());
// 目录递归 isDirectory判断是否是目录
if (file.isDirectory()){
File[] files = file.listFiles();
for (File f:files){
printFile(f.getPath(),depth+1 );
}
}
}
public static void main(String[] args) {
// copyFile("D:\\javaidea\\IntelliJ IDEA 2021.1.3\\icons.db","D:\\javaidea\\");
copyTxtFile("D:\\DXL\\dfsf.txt","D:\\DXL\\dfsf副本.txt");
}
public static void copyFile(String srcFilePath,String destFile){
try (
FileInputStream fis=new FileInputStream(srcFilePath);
FileOutputStream fos= new FileOutputStream(destFile)
){
byte[] bytes = new byte[128];
int len=0;//实际获取的字节数
while ((len=fis.read(bytes, 0,bytes.length))>0){
fos.write(bytes,0,len);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
// 拷贝文本文件
public static void copyTxtFile(String srcFilePath,String destFile){
try (
FileReader fr =new FileReader(srcFilePath);
FileWriter fw= new FileWriter(destFile);
){
char[] chars=new char[128];
int len=0;//获取实际读取的字符数
while ((len=fr.read(chars,0, chars.length))>0){
System.out.println(String.valueOf(chars, 0, len));
fw.write(chars,0,len);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
long l = System.currentTimeMillis();
copyFile("D:\\下载集中地\\BaiduNetdisk_7.4.3.3.exe","D:\\下载集中地\\BaiduNetdisk副本_7.4.3.3.exe");
long end = System.currentTimeMillis();
System.out.println("用时:;" + (end - l));
}
public static void copyFile(String scrFile,String desFile){
try (
BufferedInputStream bis= new BufferedInputStream(new FileInputStream(scrFile));
BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(desFile));
// FileInputStream bis = new FileInputStream(scrFile);
// FileOutputStream bos = new FileOutputStream(desFile);
){
byte[] bytes = new byte[128];
int len=0;
while ((len=bis.read(bytes,0,bytes.length))>0){
bos.write(bytes,0,len);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
第一个是缓冲流复制时间 第二个是文件流复制时间
public static void main(String[] args) {
try (
InputStreamReader r=new InputStreamReader(System.in);
BufferedReader br=new BufferedReader(r);
){
String line=null;
while ((line=br.readLine())!=null){
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
testPrintStream();
}
public static void testPrintStream() {
try (
FileOutputStream fos=new FileOutputStream("D:\\DXL\\dfsf.txt");
PrintStream ps=new PrintStream(fos);
){
ps.println("我爱");
ps.print("java");
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
