Java基础学习02--I/O字符流基本使用

 1 package io.demo.chars;
 2 
 3 import java.io.FileReader;
 4 
 5 //使用FileReader读取文件，可读取英文也可以读取中文等各种文字
 6 public class filedemo01 {
 7     public static void main(String[] args) throws Exception {
 8         FileReader fileReader = new FileReader("/Users/yangasen/Downloads/hello.txt");
 9 //        int data = 0;
10 //        while ((data = fileReader.read()) != -1) {
11 //            System.out.print((char) data);
12 //        }
13         System.out.println("---------------------");
14 
15         char[] chars = new char[1024];
16         int count = 0;
17         while ((count = fileReader.read(chars)) != -1) {
18             System.out.print(new String(chars, 0, count));
19         }
20 
21         fileReader.close();
22     }
23 }

 1 package io.demo.chars;
 2 
 3 import java.io.FileWriter;
 4 
 5 //写入文件
 6 public class filedemo02 {
 7     public static void main(String[] args) throws Exception {
 8         FileWriter fileWriter = new FileWriter("/Users/yangasen/Downloads/hello2.txt");
 9         for (int i = 0; i < 10; i++) {
10             fileWriter.write("我2D天下无敌!\r\n");
11             fileWriter.flush();
12         }
13         fileWriter.close();
14     }
15 }

 1 package io.demo.chars;
 2 
 3 import java.io.FileReader;
 4 import java.io.FileWriter;
 5 
 6 //复制文件，只能复制文本文件
 7 public class filedemo03 {
 8     public static void main(String[] args) throws Exception {
 9         FileReader fileReader = new FileReader("/Users/yangasen/Downloads/hello2.txt");
10         FileWriter fileWriter = new FileWriter("/Users/yangasen/Downloads/hello3.txt");
11         int data = 0;
12         while ((data = fileReader.read()) != -1) {
13             fileWriter.write(data);
14         }
15         fileReader.close();
16         fileWriter.close();
17     }
18 }

 1 package io.demo.chars;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.FileReader;
 5 
 6 //BufferedReader读取文件
 7 public class buffereddemo01 {
 8     public static void main(String[] args) throws Exception {
 9         FileReader fileReader = new FileReader("/Users/yangasen/Downloads/hello2.txt");
10         BufferedReader bufferedReader = new BufferedReader(fileReader);
11         String str = "";
12         while ((str = bufferedReader.readLine()) != null) {
13             System.out.println(str);
14         }
15         bufferedReader.close();
16     }
17 }

 1 package io.demo.chars;
 2 
 3 import java.io.BufferedWriter;
 4 import java.io.FileWriter;
 5 import java.io.IOException;
 6 
 7 //BufferedWriter
 8 public class buffereddemo02 {
 9     public static void main(String[] args) throws IOException {
10         FileWriter fileWriter = new FileWriter("/Users/yangasen/Downloads/hello4.txt");
11         BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
12         for (int i = 0; i < 10; i++) {
13             bufferedWriter.write("莫非朕不知兵?");
14             bufferedWriter.newLine();
15         }
16         bufferedWriter.close();
17 
18     }
19 }

 1 package io.demo.chars;
 2 
 3 import java.io.PrintWriter;
 4 
 5 public class printdemo {
 6     public static void main(String[] args) throws Exception {
 7         PrintWriter printWriter = new PrintWriter("/Users/yangasen/Downloads/print.txt");
 8         printWriter.println(97);
 9 
10         printWriter.println(true);
11 
12         printWriter.println(3.14);
13 
14         printWriter.println(‘x‘);
15 
16         printWriter.close();
17     }
18 }

 1 package io.demo.chars;
 2 
 3 
 4 import java.io.FileInputStream;
 5 import java.io.InputStreamReader;
 6 
 7 public class streamdemo01 {
 8     public static void main(String[] args) throws Exception {
 9         FileInputStream fileInputStream = new FileInputStream("/Users/yangasen/Downloads/hello3.txt");
10         InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, "utf-8");
11         int data = 0;
12         while ((data = inputStreamReader.read()) != -1) {
13             System.out.print((char) data);
14         }
15         inputStreamReader.close();
16     }
17 }

 1 package io.demo.chars;
 2 
 3 import java.io.FileOutputStream;
 4 import java.io.OutputStreamWriter;
 5 
 6 public class streamdemo02 {
 7     public static void main(String[] args) throws Exception {
 8         FileOutputStream fileOutputStream = new FileOutputStream("/Users/yangasen/Downloads/hello5.txt");
 9         OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream, "utf-8");
10         for (int i = 0; i < 10; i++) {
11             outputStreamWriter.write("君不见董卓，丁原乎？\r\n");
12         }
13         outputStreamWriter.close();
14     }
15 }