java FileWriter 追加文件及文件改名方式

FileWriter 追加文件及文件改名

我就废话不多说了，大家还是直接看代码吧~

import java.io.File;import java.io.FileWriter;import java.io.IOException;public class FileWriterUtil {    /**     * 追加文件：使用FileWriter     */    public static void appendMethod(String fileName, String content) {        try {            //打开一个写文件器，构造函数中的第二个参数true表示以追加形式写文件            FileWriter writer = new FileWriter(fileName, true);            writer.write(content);            writer.close();        } catch (IOException e) {            e.printStackTrace();        }    }    /**     * 修改文件名     * @param oldFilePath     * @param newFileName     */    public static void reNameLogFile(String oldFilePath,String newFileName){        File f=new File(oldFilePath);        String c=f.getParent();//        File mm=new File(c + File.pathSeparator + newFileName + "_" + CommonUtil.getCurrTimeForString());        File mm=new File(c + "/" + newFileName + "_" + CommonUtil.getBeforeDateStr());        if(f.renameTo(mm)){            System.out.println("修改文件名成功!");        }else{            System.out.println("修改文件名失败");        }    }    public static void main(String[] args) {        String fileName = "/Users/qin/Downloads/callLog.txt";        String content = "new append!";        FileWriterUtil.appendMethod(fileName, content);        FileWriterUtil.appendMethod(fileName, "append end. \n");        FileWriterUtil.reNameLogFile("/Users/qin/Downloads/callLog.txt","rayda");    }}

Java PrintWriter&FileWriter 写入追加到文件用PrintWriter写入文件

import java.io.IOException;import java.io.PrintWriter;public class PrintWriteDemo{    public static void main(String[] args) throws IOException    {        PrintWriter out = new PrintWriter("01.txt");        out.print("the quick brown fox");        out.println(" jumps over the lazy dog.");        out.write("work is like a capricious lover whose ");        out.write("incessant demands are resented but who is missed terribly when she is not there\n");        out.close(); //如果不关闭文件，文件停留在buffer zone, 不会写进"01.txt"中    }}

FileWriter只能写入文件，无法往文件中追加内容

用FileWriter写入和追加文件

import java.io.IOException;import java.io.FileWriter;public class FileWriterDemo{    public static void main(String[] args) throws IOException    {        FileWriter out = new FileWriter("02.txt");        //constructor中添加true,即FileWriter out = new FileWriter("02.txt", true)就是往02.txt中追加文件了        out.write("work is like a capricious lover whose ");        out.write("incessant demands are resented but who is missed terribly when she is not there\n");        out.write(98.7 + "\n");        out.close(); //很重要，一定记得关闭文件    }}

都别忘记 throws IOException

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。

待人对事不要太计较，如果太计较就会有悔恨！