Reader reader = new FileReader("readme.txt");

int data = reader.read(); // 读取一个字符，返回该字符代表的整数，若到达流的末尾，返回-1

Reader reader = new FileReader("readme.txt");

// 读取字符到数组中，返回读取的字符数，若到达流的末尾，返回-1
char[] chs = new char[2048];
int len = r.read(chs);

Writer writer = new FileWriter("dest.txt");

int x = ‘中‘;
writer.write(x); // 写一个字符

Writer writer = new FileWriter("dest.txt")

char[] chs = {‘橙‘, ‘心‘, ‘橙‘, ‘意‘};
writer.write(chs); // 写一个字符数组

writer.write("小黑爱学习"); // 写入一个字符串

Reader reader = new FileReader("readme.txt");

Writer writer = new FileWriter("dest.txt");

int data = reader.read();

writer.write(data);

Reader reader = new FileReader("readme.txt");

Writer writer = new FileWriter("dest.txt");

char[] chs = new char[2048];
int len = reader.read(chs);

writer.write(chs);