文件操作

文件读/写/创建

package FileDemo;

import java.io.*;

public class FileUtils {

    public static File createJson(String filename){

        return new File(System.getProperty("user.dir")+filename+".json");
    }

    public static void write(File filename, String context) throws IOException {
        FileWriter fw = new FileWriter(filename);
        BufferedWriter bw = new BufferedWriter(fw);
        bw.write(context);
        bw.flush();
    }

    public static String read(String filename){

        int len=0;
        StringBuffer str = new StringBuffer();
        try {
            FileReader fr = new FileReader(filename);
            BufferedReader br = new BufferedReader(fr);
            String line;

            while( (line=br.readLine())!=null )
            {
                if(len != 0)  // 处理换行符的问题
                {
                    str.append("\r\n"+line);
                }
                else
                {
                    str.append(line);
                }
                len++;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return str.toString().trim();
    }

}

递归查找所有文件

package FileDemo;

import java.io.File;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

public class ReadAllFiles {

    public static void main(String[] args) {
        recursiveReadFile("C:\\Users\\somebody\\Desktop\\My photos");
    }

    public static void recursiveReadFile(String filepath){
        List<File> fileList = new ArrayList<>();
        File file = new File(filepath);
        File[] files = file.listFiles();

        if(files == null)
            return;

        for (File f: files) {
            if(f.isFile()){
                fileList.add(f);
            }
            else if(f.isDirectory()){
                recursiveReadFile(f.getAbsolutePath());
            }
        }

        for(File f:fileList){
            System.out.println(f.getName() + " ");
        }
    }
}