Java通过阅读器书写器实现按编码读写字符

来源：互联网发布：詹姆斯总决赛场均数据编辑：程序博客网时间：2024/06/05 14:59

一，简介

通过按字节的方式读写文件，实际上是比较底层的，并不算方便。实际程序员可能更喜欢指定编码（如UTF-8），并按字符读写。

Java提供了封装好的阅读器、书写器替我们完成了流-字符转换，我们直接可以操作读写字符的函数即可。

二，示例

工具类

//工具类package com.maoge.stream;import java.io.File;public class StreamUtils {    //用于定义每次读取的长度    public static final int BUFFER_LENGTH=512;    //文件对象    public static File FILE_FOR_READ;    public static File FILE_FOR_WRITE;    static{        FILE_FOR_READ=new File("C:\\test.txt");         FILE_FOR_WRITE=new File("C:\\result.txt");     }}

阅读器、书写器

package com.maoge.stream;import java.io.BufferedReader;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;//阅读器、书写器示例public class ReaderWriterDemo {    //测试入口    public static void main(String[] args){        //书写器OutputStreamWriter示例        writeText("哈利路亚");        //阅读器InputStreamReader示例        readText();        //可以在InputStreamReader上再串联一个BufferedReader，实现按行读取，这个就非常方便了。        System.out.println("开始按行读取");         readLine();    }    public static void writeText(String text){        OutputStreamWriter out=null;        try {            //OutputStreamWriter是按字符（非字节了）方式写入，同时可以指定编码            out=new OutputStreamWriter(new FileOutputStream(StreamUtils.FILE_FOR_WRITE),"UTF-8");            out.write(text);            out.flush();        } catch (Exception e) {            System.out.println(e.toString());        }finally{            try {                out.close();            } catch (IOException e) {                System.out.println(e.toString());            }        }    }    public static void readText(){        InputStreamReader in=null;        try{            //注意阅读器一次读取一个字符            in=new InputStreamReader(new FileInputStream(StreamUtils.FILE_FOR_READ),"UTF-8");            StringBuilder sb=new StringBuilder();            int readInt;            while((readInt=in.read())!=-1)                sb.append((char)readInt);            System.out.println(sb.toString());        }catch(Exception e){            System.out.println(e.toString());        }finally{            try {                in.close();            } catch (IOException e) {                System.out.println(e.toString());            }        }    }    public static void readLine(){        BufferedReader br=null;        try{            br=new BufferedReader(new InputStreamReader(new FileInputStream(StreamUtils.FILE_FOR_READ),"UTF-8"));            String line = null;            while((line = br.readLine())!=null)            {                System.out.println(line);             }        }catch(Exception e){            System.out.println(e.toString());        }finally{            try {                br.close();            } catch (IOException e) {                System.out.println(e.toString());            }        }    }}

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