IO复制文件（字符流）

ゞ浴缸里的玫瑰 2022-01-15 03:29 305阅读 0赞

**复制文本文件**

分析：  
复制数据，如果我们知道用记事本打开并能够读懂，就用字符流，否则用字节流。  
通过该原理，我们知道我们应该采用字符流更方便一些。  
而字符流有5种方式，所以做这个题目我们有5种方式。推荐掌握第5种。  
数据源：  
目的地：  
d:\\b.txt – FileWriter – BufferedWriter

public class CopyFileDemo4 {
    public static void main(String[] args) throws IOException {
    	String srcString = "c:\\a.txt";
    	String destString = "d:\\b.txt";
    	// method1(srcString, destString);
    	// method2(srcString, destString);
    	// method3(srcString, destString);
    	// method4(srcString, destString);
    	 method5(srcString, destString);	
    }
    
    private static void method1(String srcString, String destString) throws IOException {
    	// 字符缓冲流一次读写一个字符串
    	BufferedReader br = new BufferedReader(new FileReader(srcString));
    	BufferedWriter bw = new BufferedWriter(new FileWriter(destString));
    	 String line=null;
    	 while((line=br.readLine())!=null) {
    		 bw.write(line);
    		 bw.newLine();
    		 bw.flush();
    	 }
    }
    private static void method2(String srcString, String destString) throws IOException {
    	// 字符缓冲流一次读写一个字符数组
    	BufferedReader br = new BufferedReader(new FileReader(srcString));
    	BufferedWriter bw = new BufferedWriter(new FileWriter(destString));
    	char[] c = new char[1024];
    	int len = 0;
    	while((len=br.read(c)) != -1) {
    		bw.write(c,0,len);
    	}
    	bw.close();
    	br.close();
    }
    private static void method3(String srcString, String destString) throws IOException {
    	// 字符缓冲流一次读写一个字符
    	BufferedReader br = new BufferedReader(new FileReader(srcString));
    	BufferedWriter bw = new BufferedWriter(new FileWriter(destString));
    	int ch = 0;
    	while((ch=br.read())!=-1) {
    		bw.write(ch);
    	}
    	bw.close();
    	br.close();
    }
    private static void method4(String srcString, String destString) throws IOException {
    	// 基本字符流一次读写一个字符数组
    	FileReader fr = new FileReader(srcString);
    	FileWriter fw = new FileWriter(destString);
    	char[] c = new char[1024];
    	int len=0;
    	while((len=fr.read(c))!=-1) {
    		fw.write(c,0,len);
    	}
    	fw.close();
    	fr.close();
    }
    private static void method5(String srcString, String destString) throws IOException {
    	// 基本字符流一次读写一个字符
    	FileReader fr = new FileReader(srcString);
    	FileWriter fw = new FileWriter(destString);
    	int ch = 0;
    	while ((ch = fr.read()) != -1) {
    		fw.write(ch);
    	}
    	fw.close();
    	fr.close();
    }
    }