Java_基础—字符流FileReader

package com.soar.chario;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class Demo1_FileReader {
    /*
*** 1.字符流是什么
    * 字符流是可以直接读写字符的IO流
    * 字符流读取字符, 就要先读取到字节数据, 然后转为字符. 如果要写出字符, 需要把字符转为字节再写出.    
*** 2.FileReader
    * FileReader类的read()方法可以按照字符大小读取
    * 
    * FileReader fr = new FileReader("aaa.txt");    //创建输入流对象,关联aaa.txt
        int ch;
        while((ch = fr.read()) != -1) {             //将读到的字符赋值给ch
            System.out.println((char)ch);           //将读到的字符强转后打印
        }

        fr.close();                                 //关流 
     */
    public static void main(String[] args) throws IOException {
        //read();
        FileReader fr = new FileReader("xxx.txt");
        int c;
        while((c = fr.read()) != -1){               //通过项目默认的码表一次读取一个字符
            System.out.print((char)c);
        }
        fr.close();
    }

    private static void read() throws FileNotFoundException, IOException {
        FileReader fr = new FileReader("xxx.txt");
        int x = fr.read();
        System.out.println(x);
        //向下强转，将字符拿出
        char c = (char) x;
        System.out.println(c);
        fr.close();
    }

}