Java I/O 学习笔记（实战篇）

本篇将进行Java I/O的实际操作。

简单的输入输出流操作

/** * Created by Mr.W on 2017/11/9. */public class IOClass {    public static void main(String[] args) throws IOException {        File file = new File("./src/com/stupidzhe/jdklearning/io/file-test/file1.c");        // output        FileOutputStream outputStream = new FileOutputStream(file);                        // 实例化装饰器类，这里我们使用PrintStream        // 第一个参数：outputStream        // 第二个参数：是否每次换行时清空缓冲        PrintStream printStream = new PrintStream(outputStream, false);        printStream.print("hello world!");        printStream.flush();           	 	printStream.close();   	 	outputStream.close();   	 	        // input        FileInputStream fileInputStream = new FileInputStream(file);        BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream);        byte[] bytes = bufferedInputStream.readAllBytes();        String content = new String(bytes);        System.out.println(content);                bufferedInputStream.close();        fileInputStream.close();    }}------output------hello world!------------------

上述代码使用了FileOutputStream来作为输出流，PrintStream作为OutputStream的装饰器类，使用FileInputStream作为输入流，BufferedInputStream作为InputStream的装饰器类。

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public class ReaderAndWriterClass {    public static void main(String[] args) throws IOException {        File file = new File("./src/com/stupidzhe/jdklearning/io/file-test/file2.c");        FileWriter fileWriter = new FileWriter(file, false);        String content = "你好,世界!\n我爱你！";        fileWriter.write(content);        fileWriter.flush();        fileWriter.close();        FileReader fileReader = new FileReader(file);        int i;        while ((i = fileReader.read()) != -1)            System.out.print((char) i);        fileReader.close();    }}-------output-------你好,世界!我爱你！--------------------

上述代码使用了FileWriter类与FileReader类作为文件输入输出流。相对于InputStream和OutputStream面向字节的流，Writer和Reader是面向字符的。

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