BufferedWriter wr = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("D:\\java学习代码\\iotest\\io.txt"),"GBK"));这句代码的原理
时间: 2023-09-28 11:10:44 浏览: 36
这句代码主要实现了将数据写入文件的功能。具体解释如下:
1. FileOutputStream("D:\\java学习代码\\iotest\\io.txt"):创建一个文件输出流,将数据写入到指定的文件中。
2. new OutputStreamWriter():将字节流转换为字符流,可以指定编码格式。这里使用了"GBK"编码格式。
3. new BufferedWriter():创建一个缓冲字符输出流,提高了写入效率,可以一次写入多个字符。
综合起来,这句代码的作用是:创建一个以GBK编码格式的缓冲字符输出流,将数据写入到指定的文件中。
相关问题
BufferedWriter wr = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("D:\\java学习代码\\iotest\\io.txt"),"GBK"));
This line of code creates a BufferedWriter object which writes to a file named "io.txt" located in the directory "D:\java学习代码\iotest\". The data written to the file will be encoded using the character set "GBK". The code uses a FileOutputStream to write bytes to the file, and an OutputStreamWriter to convert the bytes to characters using the specified character set. Finally, a BufferedWriter is used to buffer the output and improve performance.
将这段代码改为续写文件 FileOutputStream fileOutputStream = new FileOutputStream("factoryer.txt"); OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream, "UTF-8"); BufferedWriter writer = new BufferedWriter(outputStreamWriter);
要将这段代码修改为续写文件,可以在FileOutputStream的构造函数中传入第二个参数true,表示以追加的方式打开文件。另外,可以在BufferedWriter的构造函数中传入FileOutputStream对象,以实现续写文件的功能。以下是修改后的示例代码:
```java
import java.io.*;
public class FileWriterAppendExample {
public static void main(String[] args) {
String fileName = "factoryer.txt";
String content = "Hello, world!";
try {
FileOutputStream fileOutputStream = new FileOutputStream(fileName, true); // 第二个参数为true表示续写文件
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream, "UTF-8");
BufferedWriter writer = new BufferedWriter(outputStreamWriter);
writer.write(content);
writer.newLine(); // 换行
writer.close();
System.out.println("内容已经成功续写到文件" + fileName + "中。");
} catch (IOException e) {
System.out.println("写入文件出错:" + e.getMessage());
}
}
}
```
在上面的代码中,我们在FileOutputStream的构造函数中传入了第二个参数true,以实现续写文件的功能。另外,我们还在BufferedWriter的构造函数中传入了FileOutputStream对象,以实现续写文件的功能。注意,如果文件不存在,FileOutputStream会自动创建一个新文件。另外,我们还使用了newLine()方法来换行,以使文件内容更加清晰。