IO流(9)--字符流的三种拷贝

字符流FileReader

public static void main(String[] args) throws IOException {        FileReader fr=new FileReader("xxx.txt");        int b;        while((b=fr.read())!=-1){            System.out.print((char)b);  //因为是中文，所以要强制转换        }        fr.close();    }

FileWriter

public static void main(String[] args) throws IOException {        FileWriter fw=new FileWriter("yyy.txt");        fw.write("大家好,hahaha");        fw.write(97);   //会写一个  a  在文件yyy.txt中        fw.close();    }

字符流的拷贝

public static void main(String[] args) throws IOException {        FileReader fr=new FileReader("xxx.txt");        FileWriter fw=new FileWriter("yyy.txt");        int c;        while((c=fr.read())!=-1){            fw.write(c);        }        fr.close();        fw.close();         //writer类中有一个2K的缓冲区，如果不关流，就会将内容写到缓冲区里    }

带有数组的拷贝

public static void main(String[] args) throws IOException {        FileReader fr=new FileReader("xxx.txt");        FileWriter fw=new FileWriter("yyy.txt");        char[] arr=new char[1024];        int len;        while((len=fr.read(arr))!=-1){  //将文件上的数据读取到字符数组中            fw.write(len);              //将字符数组中的数据写到文件上        }        fr.close();        fw.close();    }

带有缓冲区的字符流拷贝

public static void main(String[] args) throws IOException {        BufferedReader br=new BufferedReader(new FileReader("xxx.txt"));        BufferedWriter bw=new BufferedWriter(new FileWriter("zzz.txt"));        int b;        while((b=br.read())!=-1){            bw.write(b);        }        br.close();        bw.close();    }