java 创建文件，写入文件，读取文件、删除文件

package com.sensorsdata.analytics.javasdk.util;

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

/**
 * @Author chenRuiFu
 * @Date 2021/1/28 9:52
 * @Version 1.0
 */
public class FileUtil {
    //生成文件路径
    private static String path = "D:\\file\\MqCloud\\";

    //文件路径+名称
    private static String filenameTemp;
    /**
     * 创建文件
     * @param fileName  文件名称
     * @param filecontent   文件内容
     * @return  是否创建成功，成功则返回true
     */
    public static boolean createFile(String fileName,String filecontent){
        Boolean bool = false;
        filenameTemp = path+fileName+".txt";//文件路径+名称+文件类型
        File file = new File(filenameTemp);
        try {
            //如果文件不存在，则创建新的文件
            if(!file.exists()){
                file.createNewFile();
                bool = true;
                System.out.println("success create file,the file is "+filenameTemp);
                //创建文件成功后，写入内容到文件里
                writeFileContent(filenameTemp, filecontent);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return bool;
    }

    /**
     * 向文件中写入内容
     * @param filepath 文件路径与名称
     * @param newstr  写入的内容
     * @return
     * @throws IOException
     */
    public static boolean writeFileContent(String filepath,String newstr) throws IOException {
        Boolean bool = false;
        String filein = newstr+"\r\n";//新写入的行，换行
        String temp  = "";

        FileInputStream fis = null;
        InputStreamReader isr = null;
        BufferedReader br = null;
        FileOutputStream fos  = null;
        PrintWriter pw = null;
        try {
            File file = new File(filepath);//文件路径(包括文件名称)
            //将文件读入输入流
            fis = new FileInputStream(file);
            isr = new InputStreamReader(fis);
            br = new BufferedReader(isr);
            StringBuffer buffer = new StringBuffer();

            //文件原有内容
            for(int i=0;(temp =br.readLine())!=null;i++){
                buffer.append(temp);
                // 行与行之间的分隔符 相当于“\n”
                buffer = buffer.append(System.getProperty("line.separator"));
            }
            buffer.append(filein);

            fos = new FileOutputStream(file);
            pw = new PrintWriter(fos);
            pw.write(buffer.toString().toCharArray());
            pw.flush();
            bool = true;
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }finally {
            //不要忘记关闭
            if (pw != null) {
                pw.close();
            }
            if (fos != null) {
                fos.close();
            }
            if (br != null) {
                br.close();
            }
            if (isr != null) {
                isr.close();
            }
            if (fis != null) {
                fis.close();
            }
        }
        return bool;
    }

    public static List getFileList() {
        List list = new ArrayList();
        try {
            File file = new File(path);
            String[] filelist = file.list();
            for (int i = 0; i < filelist.length; i++) {
                list.add(path+"\\"+filelist[i]);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return list;
    }


    /**
     * @Title: readTxt
     * @Description: 读取txt文件内容
     * @param filePath
     * @return
     */
    public static String readTxt(String filePath) {
        StringBuilder result = new StringBuilder();
        try {
            BufferedReader bfr = new BufferedReader(new InputStreamReader(new FileInputStream(new File(filePath)), "UTF-8"));
            String lineTxt = null;
            while ((lineTxt = bfr.readLine()) != null) {
                result.append(lineTxt).append("\n");
            }
            bfr.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result.toString();
    }

    /**
     * 删除文件
     * @param filepath 指定得路径
     */
    public static void delFile(String filepath) {
        try {
            String filePath = filepath;
            filePath = filePath.toString();
            java.io.File myDelFile = new java.io.File(filePath);
            myDelFile.delete();
        } catch (Exception e) {
            System.out.println("删除文件操作出错");
            e.printStackTrace();
        }
    }
   /* public static void main(String[] args) {
        UUID uuid = UUID.randomUUID();
        createFile(uuid+"myfile", "我的梦说别停留等待,就让光芒折射泪湿的瞳孔,映出心中最想拥有的彩虹,带我奔向那片有你的天空,因为你是我的梦 我的梦");
    }*/
}