Java读取txt文件和覆盖写入txt文件和追加写入txt

package thread;

import java.io.*;

public class hh {

/**     * 创建文件     * @param fileName     * @return     */    public static boolean createFile(File fileName)throws Exception{        try{            if(!fileName.exists()){                fileName.createNewFile();            }        }catch(Exception e){            e.printStackTrace();        }        return true;    }

/**     *读取TXT内容     * @param file     * @return     */    public static String readTxtFile(File file){        String result = "";        try {            InputStreamReader reader = new InputStreamReader(new FileInputStream(file),"gbk");            BufferedReader br = new BufferedReader(reader);            String s = null;            while((s=br.readLine())!=null){                result = result  + s;                System.out.println(s);            }        } catch (Exception e) {            e.printStackTrace();        }        return result;    }

/**     * 写入TXT，覆盖原内容     * @param content     * @param fileName     * @return     * @throws Exception     */    public static boolean writeTxtFile(String content,File fileName)throws Exception{        RandomAccessFile mm=null;        boolean flag=false;        FileOutputStream fileOutputStream=null;        try {            fileOutputStream = new FileOutputStream(fileName);            fileOutputStream.write(content.getBytes("gbk"));            fileOutputStream.close();            flag=true;        } catch (Exception e) {            e.printStackTrace();        }        return flag;    }

/**     * 写入TXT，追加写入     * @param filePath     * @param content     */    public static void fileChaseFW(String filePath, String content) {        try {            //构造函数中的第二个参数true表示以追加形式写文件            FileWriter fw = new FileWriter(filePath,true);            fw.write(content);            fw.close();        } catch (IOException e) {            System.out.println("文件写入失败！" + e);        }    }

public static void main(String[] args) throws Exception{        File file = new File("D:\\123wu吴.txt");        createFile(file);        readTxtFile(file);//        writeTxtFile("我是写入的内容11",file);        fileChaseFW("D:\\123wu吴.txt","66666666");    }}