Java（五十五）转换流（InputStreamReader和OutputStreamWriter）

今天我们来学习流的最后一部分：转换流InputStreamReader和OutputStreamWriter，缓冲转换流：BufferedReader和BufferedWriter

这几个我们学一下构造方法就可以了。成员方法跟字符流的都一样。

一：什么是转换流？

可以将字节流转换成字符流

转换流是所有流中唯一能设置编码方式的流

二：InputStreamReader

1 ：构造方法

(1):public InputStreamReader(InputStream in)

(2):public InputStreamReader(InputStream in,String charsetName)

具体使用参见文件复制粘贴

三：OutputStreamWriter

1 ：构造方法

(1):public OutputStreamWriter(OutputStream out)

(2):public OutputStreamWriter(OutputStream out,String charsetName)

具体使用参见文件复制粘贴

四：文件复制粘贴

1 ：一次复制一个字符，一次写入一个字符

java 复制代码

public static void main(String[] args) {
        try {
            InputStreamReader inp = new InputStreamReader(new FileInputStream("aaa.txt"));
            OutputStreamWriter outp = new OutputStreamWriter(new FileOutputStream("bbb.txt", true));
            int len = 0;
            while ((len = inp.read()) != -1) {
                outp.write(len);
            }
            outp.flush();
            System.out.println("复制成功！");
        } catch (Exception e) {
            System.out.println("出错了！");
        }
    }

2 ：一次读取一个字符数组，一次写出一个字符数组的一部分

java 复制代码

    public static void main(String[] args) {
        try {
            InputStreamReader inp = new InputStreamReader(new FileInputStream("aaa.txt"));
            OutputStreamWriter outp = new OutputStreamWriter(new FileOutputStream("ccc.txt", true));
            char[] ch = new char[1024];
            int len = 0;
            while ((len = inp.read(ch)) != -1) {
                outp.write(ch, 0, len);
            }
            outp.flush();
            System.out.println("复制成功！");
        } catch (Exception e) {
            System.out.println("出错了！");
        }
    }

3 ：缓冲转换流：一次读取一个字符，一次写出一个字符

java 复制代码

    public static void main(String[] args) {
        try {
            BufferedReader inp = new BufferedReader(new InputStreamReader(new FileInputStream("aaa.txt")));
            BufferedWriter outp = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("ddd.txt", true)));
            int len = 0;
            while ((len = inp.read()) != -1) {
                outp.write(len);
            }
            outp.flush();
            System.out.println("复制成功！");
        } catch (Exception e) {
            System.out.println("出错了！");
        }
    }

4 ：缓冲转换流：一次读取一个字符数组，一次写出一个字符数组的一部分

java 复制代码

    public static void main(String[] args) {
        try {
            BufferedReader inp = new BufferedReader(new InputStreamReader(new FileInputStream("aaa.txt")));
            BufferedWriter outp = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("ccc.txt", true)));
            char[] ch = new char[1024];
            int len = 0;
            while ((len = inp.read(ch)) != -1) {
                outp.write(ch, 0, len);
            }
            outp.flush();
            System.out.println("复制成功！");
        } catch (Exception e) {
            System.out.println("出错了！");
        }
    }

5 ：一次读取一行，一次写出一行

java 复制代码

    public static void main(String[] args) {
        try {
            BufferedReader inp = new BufferedReader(new InputStreamReader(new FileInputStream("aaa.txt")));
            BufferedWriter outp = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("ccc.txt", true)));
            String line = null;
            while ((line = inp.readLine()) != null) {
                line += "\n";
                outp.write(line);
            }
            outp.flush();
            System.out.println("复制成功！");
        } catch (Exception e) {
            System.out.println("出错了！");
        }
    }

以上大概就是转换流的基本使用。

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