File操作一些常用场景

package test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class Main {
	//查找所有file文件
	List<File> javalistfile = new ArrayList<File>();
	if(file.isFile()){
		String fileName = file.getName();
		
		if(fileName.substring(fileName.lastIndexOf(".")+1).equals("java")){
			javalistfile.add(file);
		}
	}
	
	//字节流输入文件
	FileOutputStream fio = new FileOutputStream(new File("F:/test.txt"));
	String testStr = "this is test";
	fio.write(testStr.getBytes());
	fio.write("\r\n".getBytes());
	
	
	//阅读某个文件
	InputStreamReader isr = new InputStreamReader(new FileInputStream(fir),"GBK");
	BufferedReader br = new BufferedReader(isr);
	String str = null;
	while((str = br.readLine()) != null){
		if(!str.startsWith("//") && !str.equals("")){
			num++;
		}
	}
	br.close();
	
	
	//获取file下的所有file
	public void getAllFile(String path){
		File file = new File(path);
		if(file.exists()){
			if(file.isFile()){
				System.out.println(file.getName());
			}else{
				File[] files = file.listFiles();
				if(files != null){
					for(File f:files){
						getAllFile(f.getPath());
					}
				}
			}
		}
	}
	
	File delFile = new File("D:/TEST");
	private void deleteFile(File file){
		if(file.isFile()){
			file.delete();
		}else{
			File[] files = file.listFiles();
			if(files != null){
				for(File f:files){
					deleteFile(f);
				}
			}
		}
	}
	
	
	
	
	
	
	
	
}