本文主要是介绍IO流（二）FileReader与FileWriter，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
能用记事本编辑的都是普通文本文件 不一定是1.txt 如1.java
一.FileReader
package com.io;import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;/*
FileReader :文件字符输入流，只能读取普通文本读取文本内容时，比较方便，快捷*/
public class FileReaderTest {public static void main(String[] args) {FileReader reader =null;try {//创建文件字符输入流reader = new FileReader("temp.txt");char[] chars = new char[4];//一次读取4个字符int readCount = 0;while((readCount = reader.read(chars))!=-1){System.out.print(new String(chars,0,readCount));}} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} finally {if (reader != null) {try {reader.close();} catch (IOException e) {e.printStackTrace();}}}}
}
二.FileWriter
package com.io;import java.io.FileWriter;
import java.io.IOException;/*FileWriterTest:文件字符输出流。写只能输出普通文本*/
public class FileWriterTest {public static void main(String[] args) {FileWriter out =null;try {//创建文件字符输出流对象//out = new FileWriter("file");//以追加的形式在文件末写入out = new FileWriter("file",true);out.write("我长得是真的帅");char[] chars ={'帅','是','真','的','帅'};out.write(chars ,0,5);out.flush();} catch (IOException e) {e.printStackTrace();}finally {if (out != null) {try {out.close();} catch (IOException e) {e.printStackTrace();}}}}
}
三.文件拷贝
package com.io;import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;/*
使用FileReader和FileWriter进行拷贝，只能拷贝普通文本文件*/
public class copy02 {public static void main(String[] args) {FileReader in = null;FileWriter out =null;try {in =new FileReader("file");out = new FileWriter("file2");int readCount=0;char[] chars = new char[1024*502];//1MBwhile((readCount=in.read(chars))!=-1){out.write(chars,0,readCount);}out.flush();} catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}finally {if (out != null) {try {out.close();} catch (IOException e) {e.printStackTrace();}}if (in != null) {try {in.close();} catch (IOException e) {e.printStackTrace();}}}}
}
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