Java基础学习02--I/O字符流

1.FileReader与FileWriter

package io.demo.chars;

import java.io.FileReader;

//使用FileReader读取文件，可读取英文也可以读取中文等各种文字
public class filedemo01 {
    public static void main(String[] args) throws Exception {
        FileReader fileReader = new FileReader("/Users/yangasen/Downloads/hello.txt");
//        int data = 0;
//        while ((data = fileReader.read()) != -1) {
//            System.out.print((char) data);
//        }
        System.out.println("---------------------");

        char[] chars = new char[1024];
        int count = 0;
        while ((count = fileReader.read(chars)) != -1) {
            System.out.print(new String(chars, 0, count));
        }

        fileReader.close();
    }
}

package io.demo.chars;

import java.io.FileWriter;

//写入文件
public class filedemo02 {
    public static void main(String[] args) throws Exception {
        FileWriter fileWriter = new FileWriter("/Users/yangasen/Downloads/hello2.txt");
        for (int i = 0; i < 10; i++) {
            fileWriter.write("我2D天下无敌!
");
            fileWriter.flush();
        }
        fileWriter.close();
    }
}

package io.demo.chars;

import java.io.FileReader;
import java.io.FileWriter;

//复制文件，只能复制文本文件
public class filedemo03 {
    public static void main(String[] args) throws Exception {
        FileReader fileReader = new FileReader("/Users/yangasen/Downloads/hello2.txt");
        FileWriter fileWriter = new FileWriter("/Users/yangasen/Downloads/hello3.txt");
        int data = 0;
        while ((data = fileReader.read()) != -1) {
            fileWriter.write(data);
        }
        fileReader.close();
        fileWriter.close();
    }
}

2.BufferedReader与BufferedWriter

package io.demo.chars;

import java.io.BufferedReader;
import java.io.FileReader;

//BufferedReader读取文件
public class buffereddemo01 {
    public static void main(String[] args) throws Exception {
        FileReader fileReader = new FileReader("/Users/yangasen/Downloads/hello2.txt");
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        String str = "";
        while ((str = bufferedReader.readLine()) != null) {
            System.out.println(str);
        }
        bufferedReader.close();
    }
}

package io.demo.chars;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

//BufferedWriter
public class buffereddemo02 {
    public static void main(String[] args) throws IOException {
        FileWriter fileWriter = new FileWriter("/Users/yangasen/Downloads/hello4.txt");
        BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
        for (int i = 0; i < 10; i++) {
            bufferedWriter.write("莫非朕不知兵?");
            bufferedWriter.newLine();
        }
        bufferedWriter.close();

    }
}

3.PrintWriter

package io.demo.chars;

import java.io.PrintWriter;

public class printdemo {
    public static void main(String[] args) throws Exception {
        PrintWriter printWriter = new PrintWriter("/Users/yangasen/Downloads/print.txt");
        printWriter.println(97);

        printWriter.println(true);

        printWriter.println(3.14);

        printWriter.println('x');

        printWriter.close();
    }
}

4.InputStreamReader与OutputStreamWriter

package io.demo.chars;


import java.io.FileInputStream;
import java.io.InputStreamReader;

public class streamdemo01 {
    public static void main(String[] args) throws Exception {
        FileInputStream fileInputStream = new FileInputStream("/Users/yangasen/Downloads/hello3.txt");
        InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, "utf-8");
        int data = 0;
        while ((data = inputStreamReader.read()) != -1) {
            System.out.print((char) data);
        }
        inputStreamReader.close();
    }
}

package io.demo.chars;

import java.io.FileOutputStream;
import java.io.OutputStreamWriter;

public class streamdemo02 {
    public static void main(String[] args) throws Exception {
        FileOutputStream fileOutputStream = new FileOutputStream("/Users/yangasen/Downloads/hello5.txt");
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream, "utf-8");
        for (int i = 0; i < 10; i++) {
            outputStreamWriter.write("君不见董卓，丁原乎？
");
        }
        outputStreamWriter.close();
    }
}