1.字符流

Reader类

--FileReader类

--BufferedReader类

Writer类

--FileWriter类

--BufferedWriter类

一个字符一个字符的读

FileReader fr = new FileReader(file);
int n = 0;
while((n=fr.read())!=-1){
System.out.println((char)n);相比字节流 哪怕是一个一个读 也能读出中文
}
fr.close();

一行一行的读

File file = new File("f:\\图片\\6.txt");
FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);
String str = null;
while((str = br.readLine())!=null){
System.out.println(str);
}
br.close();
fr.close();

2.网络（net包）

获取自己电脑

InetAddress inet = InetAddress.getLocalHost();
System.out.println(inet.getHostName());

获取局域网中别人的电脑

InetAddress inet = InetAddress.getByName("192.168.1.55");

获取互联网中的电脑

URL url = new URL("https://www.taobao.com");
InputStream is = url.openStream();//字节流
File file = new File("f:\\图片\\taobao.html");
FileOutputStream fos = new FileOutputStream(file);
BufferedOutputStream bos = new BufferedOutputStream(fos);
int n = 0;
while((n = is.read())!=-1){//每次从服务器读取一个字节
bos.write(n);//将数据写入本地
bos.flush();//刷新
}
bos.close();
fos.close();
is.close();

----------如何转换为字符再写入到本地文件中

URL url = new URL("https://www.taobao.com");
InputStream is = url.openStream();//字节流
//三种支持汉字的编码方式：  gbk  utf-8  gb2312
InputStreamReader isr = new InputStreamReader(is,"utf-8");
BufferedReader br = new BufferedReader(isr);
File file = new File("f:\\图片\\taobao1.html");
FileWriter fw = new FileWriter(file);
BufferedWriter bw = new BufferedWriter(fw);
String str = null;
while((str=br.readLine())!=null){//从服务器读取一行
bw.write(str);//将该行写入到本地文件中
bw.flush();//刷新
}
bw.close();
fw.close();
br.close();
isr.close();
is.close();