文件边读边写java 文件读写java代码

package file;

import javax.swing.*;
import java.io.*;
import java.util.ArrayList;
import java.util.List;

public class readFile {
    //文件读取
    public static void read(String path){
        File file = new File(path);
        if (!file.isDirectory()){
            System.out.println("文件");
            System.out.println("path="+file.getPath());
            System.out.println("absolutepath="+file.getAbsolutePath());
            System.out.println("name="+file.getName());
            List<String> list = readFile(file);
            if (list.size()!=0){
                writeFile(path+"\\abc.txt",list);
            }
        }else if(file.isDirectory()){
            System.out.println("文件夹");
            String[] fileList = file.list();
            for (int i = 0; i < fileList.length; i++) {
                File readFile = new File(path+"\\"+fileList[i]);
                if (!readFile.isDirectory()){
                    System.out.println("path="+readFile.getPath());
                    List<String> list = readFile(readFile);
                    //写入一个大文件中
                    if (list.size()!=0){
                        writeFile(path+"\\abc.txt",list);
                    }
                }else if (readFile.isDirectory()){
                    read(path+"\\"+readFile);
                }
            }
        }
    }
    //文件读取
    public static List<String> readFile(File file){
        List<String> list = new ArrayList<String>();
        BufferedReader reader = null;
        InputStreamReader ior = null;
        String string = null;
        try {
            ior = new InputStreamReader(new FileInputStream(file),"UTF-8");
            reader = new BufferedReader(ior);

            while ((string = reader.readLine())!=null){
                list.add(string);
                System.out.println(string);
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if (reader!=null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (ior!=null){
                try {
                    ior.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return list;
    }
    //文件写入
    public static void writeFile(String path,List<String> list){
        File file =  new File(path);
        //FileOutputStream outStr = null;
        //BufferedOutputStream buff = null;
        BufferedWriter bw = null;
        FileWriter fw = null;
        if (!file.exists()){
            try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        try {
            //outStr = new FileOutputStream(file,true);
            //buff = new BufferedOutputStream(outStr);
            fw = new FileWriter(file,true);
            bw = new BufferedWriter(fw);//在这个位置更换为自己想使用的换行符
            String property = System.getProperty("line.separator");
            for (int i = 0; i < list.size(); i++) {
                bw.write(list.get(i));
                bw.write(property);
                //bw.newLine();
            }
            bw.flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                //buff.close();
                if (bw!=null){
                    bw.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
               /* if (outStr!=null){
                    outStr.close();
                }*/
               if (fw!=null){
                   fw.close();
               }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    //File类提供的方法
    public static void test() {
        String path = "E:\\test";
        File file = new File(path);
        file.getName();//获取文件的名称
        file.canRead();//判断文件是否为可读的
        file.canWrite();//判断文件是否为可写
        file.exists();//判断文件是否存在
        file.length();//获取文件长度（以字节为长度）
        file.getAbsolutePath();//获得文件的绝对位置
        file.getParent();//获取文件的父路径
        file.isFile();//判断未见是否存在
        file.isDirectory();//判读文件是否是一个目录
        file.isHidden();//判断文件是否为隐藏文件
        file.lastModified();//获取文件最后修改时间
         /*String str = "E:\\test1\\test.txt";
        int i = str.lastIndexOf("\\");
        //System.out.println(i);
        String s = str.substring(0,i);
        String substring = str.substring((i + 1), str.length());

        File file = new File(str);
        if (!file.getParentFile().exists()){
            System.out.println(file.getParentFile());
            file.getParentFile().mkdirs();
        }
        if (!file.exists()){
            try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }*/

        /*if (!file.exists()){
            file.mkdirs();
        }
        file = new File(str);
        System.out.println(file.getParentFile());
        if (!file.exists()){
            try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }*/
    }
    
    public static void main(String[] args) {
        String path = "E:\\test";
        read(path);
    }
}