追加文件內容的三種方法

原創

2020-02-22 16:17

import java.io.BufferedWriter;

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.RandomAccessFile;

/**
*
* @author malik
* @version 2011-3-10 下午10:49:41
*/
public class AppendFile {

   public static void method1(String file, String conent) {
        BufferedWriter out = null;
        try {
            out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file, true)));
            out.write(conent);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
               if(out != null){
                   out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 追加文件：使用FileWriter
     *
     * @param fileName
     * @param content
     */
    public static void method2(String fileName, String content) {
       FileWriter writer = null;
        try {
            // 打開一個寫文件器，構造函數中的第二個參數true表示以追加形式寫文件
            writer = new FileWriter(fileName, true);
            writer.write(content);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
               if(writer != null){
                   writer.close();
               }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 追加文件：使用RandomAccessFile
     *
     * @param fileName 文件名
     * @param content 追加的內容
     */
    public static void method3(String fileName, String content) {
       RandomAccessFile randomFile = null;
        try {
            // 打開一個隨機訪問文件流，按讀寫方式
            randomFile = new RandomAccessFile(fileName, "rw");
            // 文件長度，字節數
            long fileLength = randomFile.length();
            // 將寫文件指針移到文件尾。
            randomFile.seek(fileLength);
            randomFile.writeBytes(content);
        } catch (IOException e) {
            e.printStackTrace();
        } finally{
           if(randomFile != null){
               try {
                   randomFile.close();
               } catch (IOException e) {
                   e.printStackTrace();
               }
           }
        }
    }

   public static void main(String[] args) {
       try{
           File file = new File("d://text.txt");
           if(file.createNewFile()){
               System.out.println("Create file successed");
           }
           method1("d://text.txt", "123");
           method2("d://text.txt", "123");
           method3("d://text.txt", "123");
       }catch(Exception e){
           System.out.println(e);
       }
   }
}