java _io_轉(zhuǎn)換流輸入,讀取網(wǎng)頁(yè)源代碼和鍵盤輸入

InputStreamReader和 OutputStreamWriter

new InputStreamReader(字節(jié)流,"UTF-8") //指定模式

將字節(jié)流轉(zhuǎn)換為字符流，方便處理，比如能使用BufferedReader處理流
可以處理字符集:InputStreamReader isr=new InputStreamReader(字節(jié)流,"UTF-8");
網(wǎng)絡(luò)流:new URL("http://www.baidu.com").openStream(),這是一個(gè)字節(jié)流
用裝飾器裝飾轉(zhuǎn)換流轉(zhuǎn)換成的字符流:BufferedReader reader=new BufferedReader(new InputStreamReader(new URL("http://www.baidu.com").openStream(),"UTF-8"))

用轉(zhuǎn)換流來讀取鍵盤輸入輸出的字節(jié)流:

        try(BufferedReader isr=new BufferedReader( new 
        InputStreamReader(System.in));
    BufferedWriter osw=new BufferedWriter(new OutputStreamWriter(System.out));){
    //鍵盤循環(huán)讀取，exit退出
    String s=" ";
    while(!s.equals("exit"))
    {
            s=isr.readLine(); //按行讀取
         osw.write(s);   //寫出
         osw.newLine(); 
         osw.flush();   //強(qiáng)制刷新，因?yàn)閿?shù)據(jù)太小無(wú)法輸出，要滿足一定kb才會(huì)自動(dòng)輸出
    }

    }
    catch(IOException e)
    {
        System.out.println("操作異常");

    }

操作網(wǎng)絡(luò)流，讀取百度源碼:

使用裝飾器:

    //使用轉(zhuǎn)換流，讀取中文不會(huì)亂碼
    try(BufferedReader reader=new BufferedReader(new InputStreamReader(new URL("http://www.baidu.com").openStream(),"UTF-8"));
    ){                                                                                                  //網(wǎng)頁(yè)的字符集是utf-8

    //讀取
        String s;
        while((s=reader.readLine())!=null)
        {
            System.out.println(s);
        }

    }
    catch(IOException e)
    {
        System.out.println("操作異常");

    }
}

不使用裝飾器:

    try(InputStreamReader is=new InputStreamReader(new URL("http://www.baidu.com").openStream());
    ){

    //讀取
        int len;
        while((len=is.read())!=-1)
        {
            System.out.print((char)len);
        }

    }
    catch(IOException e)
    {
        System.out.println("操作異常");

    }