With commutations download page code

Commutations
InputStreamReader OutputStreamWriter converts a byte character operation (full-text only)

Look at the basic operation

public class 转换流_字符集 {//InputStreamReader  OutputStreamWriter 将字节转换为字符操作（仅限全文本）
public static void main(String[] args) {
	//选择源
		
			//选择流
		
			try ( 	BufferedReader in = new BufferedReader(new InputStreamReader(System.in));//缓冲流 转换流
					BufferedWriter os =new BufferedWriter(new OutputStreamWriter(System.out))
					){
		
				
			//操作(分段读取)

			String line=null;
				while((line= in.readLine())!=null) {
					
					 os.write(line);
					 os.newLine();
					 os.flush();
				}
				
			} catch (FileNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			
			}
			
}
}

Code crawling

public class 转换流之URL {
public static void main(String[] args) {
	//选择流
	
	try (
			BufferedReader in =new BufferedReader(new InputStreamReader(new URL("https://www.csdn.net/").openStream(),"UTF-8"));
			BufferedWriter os =new BufferedWriter(new FileWriter( "爬的代码.txt"));
			){
			
			
	
		
	//操作(分段读取)

String line=null;
		while((line= in.readLine())!=null) {
			
			 os.write(line);
			 os.newLine();
			 os.flush();
		}
		
	} catch (FileNotFoundException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	} catch (IOException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	
	}
}
}