File类
package demo01;
public class Demo01File {
public static void main(String[] args) throws IOException {
String pathSeparator = File.pathSeparator;
System.out.println(pathSeparator);
String separator=File.separator;
System.out.println(separator);
show06();
show07();
show08();
show11();
}
private static void show12() {
File f1 =new File("D:\\gyq\\java1\\hello.java");
boolean b1= f1.delete();
System.out.println(b1);
File f2 =new File("gyq\\11\\22\\33\\44");
boolean b2= f2.delete();
System.out.println(b2);
}
private static void show11() {
File f1 =new File("D:\\gyq\\java1\\hello.java");
boolean b1 =f1.mkdir();
System.out.println(b1);
File f2 =new File("D:\\gyq\\java1\\fss\\11\\22\\33\\44\\hello.java");
boolean b2 =f2.mkdir();
System.out.println(b2);
}
private static void show10() throws IOException {
File f1 =new File("D:\\gyq\\java1\\hello.java");
boolean b1=f1.createNewFile();
System.out.println(b1);
File f2 =new File("D:\\gyq\\java1\\新建文件夹");
boolean b2=f2.createNewFile();
System.out.println(b2);
}
private static void show09() {
File f1 =new File("D:\\gyq\\java1\\新建文件夹 (2)");
if(f1.exists()) {
System.out.println(f1.isDirectory());
System.out.println(f1.isFile());
}
File f2 =new File("D:\\gyq\\java1\\s");
if(f2.exists()) {
System.out.println(f2.isDirectory());
System.out.println(f2.isFile());
}
File f3= new File("D:\\gyq\\java1\\.settings");
if(f3.exists()) {
System.out.println(f3.isDirectory());
System.out.println(f3.isFile());
}
}
private static void show08() {
File f1 =new File("D:\\gyq\\java1");
System.out.println(f1.exists());
File f2 =new File("D:\\gyq\\java1\\s");
System.out.println(f2.exists());
File f3 =new File("D:\\gyq\\java1\\s");
System.out.println(f3.exists());
}
private static void show07() {
File f1=new File("D:\\rxp\\java\\test\\hello.java");
System.out.println(f1.length());
File f2=new File("D:\\WeGameApps\\common_apps\\ss");
System.out.println(f2.length());
File f3=new File("D:\\WeGameApps\\common_apps");
System.out.println(f3.length());
File f4=new File("D:\\rxp\\java\\20\\day20_code\\classpath");
System.out.println(f4.length());
}
private static void show06() {
File f1=new File("D:\\rxp\\java\\test\\hello.java");
File f2=new File("D:\\rxp\\java\\test");
System.out.println(f1.getName());
System.out.println(f2.getName());
}
private static void show05() {
File f1=new File("D:\\rxp\\java\\test\\hello.java");
File f2 = new File("a.txt");
String path1 =f1.getPath();
System.out.println(path1);
System.out.println(f2.getPath());
System.out.println(f1);
System.out.println(f1.toString());
}
private static void show04() {
File f1=new File("D:\\rxp\\java\\test\\hello.java");
String absolutepath1=f1.getAbsolutePath();
System.out.println(absolutepath1);
File f2 = new File("hello.java");
String absolutepath2=f2.getAbsolutePath();
System.out.println(absolutepath2);
}
private static void show03() {
File parent= new File("D:\\rxp\\java\\test");
File f1 = new File(parent , "hello.java");
System.out.println(f1);
}
private static void show02(String parent, String child) {
File f1 = new File(parent , child);
System.out.println(f1);
}
private static void show01() {
File f1 = new File("D:\\rxp\\java\\test");
System.out.println(f1);
File f2 =new File("D:\\rxp\\java\\test\\a.txt");
System.out.println(f2);
File f3 =new File("b.txt");
System.out.println(f3);
}
}
构造方法
package Demo02OutputStreqm;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class Demo02 {
public static void main(String[] args) throws IOException {
FileOutputStream fos =new FileOutputStream("a.txt");
byte[] bytes= {
80,66,64,65,65};
fos.write(bytes,2,3);
fos.close();
}
}
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