JavaIO

OutputStreamWriter #字符流=>字节流
InputStreamReader #字节流=>字符流

字符流变字节流

File file = new File("text.txt");
OutputStreamWriter writer = new OutputStreamWriter(new FileOutPutStream(file),"UTF-8");
writer.write("写入到文件里的内容");
writer.close();

字节流转字符流

File file = new File("text.txt");
InputStreamReader reader = new InputStreamReader(new FileInputStream(file),"UTF-8");
Char[] buf= new Char[1024];
int len = reader.read(buf);
buf.toString();
reader.close();