java IO流--转化流和字节流字符流的性能对比

叁歲伎倆 2024-04-18 10:00 33阅读 0赞

//字符转换流
    	static void other() throws IOException {
    		File file=new File("文件1");
    		File file1=new File("文件2");
    		
    		//使用缓冲流来实现字节流和字符流之间的转化
    		//以下是将字节流转化为字符流
    		BufferedReader br=new BufferedReader(new InputStreamReader(new FileInputStream(file)));
    		//将字符流转化为字节流
    		BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file1)));
    		String ling=null;
    		//原来readLine()方法在进行读取一行时，只有遇到回车(\r)或者换行符(\n)才会返回读取结果，这就是“读取一行的意思”，重要的是readLine()返回的读取内容中并不包含换行符或者回车符；
    		//简单的说，就是
    		//并且，当realLine()读取到的内容为空时，并不会返回 null，而是会一直阻塞，只有当读取的输入流发生错误或者被关闭时，readLine()方法才会返回null。
    		while ((ling=br.readLine())!=null) {
    			
    			bw.write(ling);
    		}
    		bw.close();
    		br.close();
    	}
    
    //不使用缓冲流，缓冲流里面只能存放字符输入流，如果要存放字节流，就只能将字节流转化为字符流
    	static void show() throws IOException {
    		File file=new File("src\\FilesList\\read.txt");
    		File file2=new File("src\\FilesList\\read1.txt");
    		BufferedReader bReader=new BufferedReader(new FileReader(file));
    		BufferedWriter bWriter=new BufferedWriter(new FileWriter(file2));
    		String lenString=null;
    		while ((lenString=bReader.readLine())!=null) {
    			bWriter.write(lenString);	
    		}
    		bWriter.close();
    		bReader.close();	
    	}
    
    //字符流--53
    		public static void readerAndWriter() throws IOException{
    			File file=new File("src\\com\\ddd");
    			File file2=new File("src\\com\\ddd2");
    			Reader reader=new FileReader(file);
    			Writer writer=new FileWriter(file2);
    			char[] data=new char[10];
    			int length=0;
    			while((length=reader.read(data))!=-1) {
    //				writer.write(new String(data,0,length));
    				writer.write(data,0,length);
    			}
    			writer.close();
    			reader.close();
    		}
    
    
    //字节缓冲流
    		static void m3() throws IOException {
    			File file=new File("src\\com\\ddd");
    			File file2=new File("src\\com\\ddd2");
    			BufferedInputStream bis=new BufferedInputStream(new FileInputStream(file));
    			BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(file2));
    			byte[] data=new byte[105];
    			int len=0;
    			while((len=bis.read(data))!=-1) {
    				bos.write(data, 0, len);
    			}
    			bos.flush();
    			bos.close();
    			bis.close();
    		}
    
    
    //字节流
    		static void m4() throws IOException {
    			File file=new File("");
    			File file2=new File("");
    			FileInputStream fis=new FileInputStream(file);
    			FileOutputStream fos= new FileOutputStream(file2);
    			byte[] bs=new byte[3];
    			int len;
    			while((len=fis.read(bs))!=-1) {
    				fos.write(bs);
    			}
    			fos.close();
    			fis.close();
    		}