java读取和写入txt的常见方法 


  1 package com.zlb.io;
  2 
  3 import java.io.BufferedReader;
  4 import java.io.BufferedWriter;
  5 import java.io.File;
  6 import java.io.FileInputStream;
  7 import java.io.FileOutputStream;
  8 import java.io.FileWriter;
  9 import java.io.IOException;
 10 import java.io.InputStreamReader;
 11 import java.io.OutputStreamWriter;
 12 import java.io.RandomAccessFile;
 13 
 14 public class ReadFileTest {
 15 
 16     /**
 17      * 读取文件
 18      * @param filePath
 19      */
 20     public void readFileByBuffered(String filePath) {
 21         
 22         File file = new File(filePath);
 23         //判断文件是否存在
 24         if (file.isFile() && file.exists()) {
 25             try {
 26                 InputStreamReader reader = null;
 27                 reader = new InputStreamReader(new FileInputStream(file), "utf-8");
 28                 BufferedReader bufferedReader = new BufferedReader(reader);
 29                 String lineContent = null;
 30                 while ((lineContent = bufferedReader.readLine()) != null) {
 31                     System.out.println(lineContent);
 32                 }
 33                 bufferedReader.close();
 34                 reader.close();
 35             } catch (Exception e) {
 36                 System.out.println("==读取文件出错," + e);
 37             } finally {
 38                 System.out.println("==文件读取完毕==");
 39             }
 40         } else {
 41             System.out.println("==文件不存在==");
 42             createFile(file);
 43             appendByBufferedWriter(file, "文件不存在，创建并写入appendByBufferedWriter");
 44             appendByRandomAccess(filePath, "文件不存在，创建并写入appendByRandomAccess");
 45             appendByFileWriter(filePath, "文件不存在，创建并写入appendByFileWriter");
 46         }
 47     }
 48 
 49     /**
 50      * 写入文件1
 51      * @param file
 52      * @param content
 53      */
 54     public static void appendByBufferedWriter(File file, String content) {
 55         
 56         try {
 57             OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(file, true));
 58             BufferedWriter bufferedWriter = new BufferedWriter(writer);
 59             bufferedWriter.write(content + "\r\n");
 60             bufferedWriter.close();
 61         } catch (Exception e) {
 62             System.out.println("==写入文件异常==" + e);
 63         }
 64     }
 65     
 66     /**
 67      * 写入文件2
 68      * @param fileName
 69      * @param content
 70      */
 71     public static void appendByRandomAccess(String fileName, String content) {
 72         try {
 73             RandomAccessFile randomFile = new RandomAccessFile(fileName, "rw");
 74             long fileLenth = randomFile.length();
 75             randomFile.seek(fileLenth);
 76             //解决存入乱码问题
 77             randomFile.writeBytes(new String(content.getBytes("gbk"), "iso8859_1") + "\r\n");
 78             randomFile.close();
 79         } catch (Exception e) {
 80             System.out.println("==写入文件异常==" + e);
 81         }
 82     }
 83     
 84     /**
 85      * 写入文件3
 86      * @param fileName
 87      * @param content
 88      */
 89     public static void appendByFileWriter(String fileName, String content) {
 90         try {
 91             FileWriter fileWriter = new FileWriter(fileName, true);
 92             fileWriter.write(content + "\r\n");
 93             fileWriter.close();
 94         } catch (IOException e) {
 95             System.out.println("==写入文件异常==" + e);
 96         }
 97         
 98     }
 99     
100     /**
101      * 创建文件和文件夹
102      * @param file
103      */
104     public void createFile(File file) {
105         System.out.println("==创建父文件夹==");
106         file.getParentFile().mkdirs();
107         try {
108             System.out.println("==创建文件==");
109             file.createNewFile();
110         } catch (IOException e) {
111             e.printStackTrace();
112         }    
113     }
114     
115     public static void main(String[] args) {
116         
117         String filePath = "d:\\Users\\lbzhao\\test\\Tools3.txt";
118         
119         ReadFileTest file = new ReadFileTest();
120         file.readFileByBuffered(filePath);
121     }
122     
123 }


以上是读写txt的主要方法，大概罗列下，经测试没有主要问题！

 

posted @ 2016-11-08 13:54  Zhao Libin  阅读(126)  评论(0)    收藏  举报