📅 最后修改于: 2020-09-27 04:48:51 🧑 作者: Mango
Java FileReader类用于从文件读取数据。它以字节格式返回数据，例如FileInputStream类。
它是面向字符的类，用于Java中的文件处理。
让我们看一下Java.io.FileReader类的声明：
public class FileReader extends InputStreamReader
| Constructor | Description |
|---|---|
| FileReader(String file) | It gets filename in string. It opens the given file in read mode. If file doesn’t exist, it throws FileNotFoundException. |
| FileReader(File file) | It gets filename in file instance. It opens the given file in read mode. If file doesn’t exist, it throws FileNotFoundException. |
| Method | Description |
|---|---|
| int read() | It is used to return a character in ASCII form. It returns -1 at the end of file. |
| void close() | It is used to close the FileReader class. |
在此示例中，我们使用Java FileReader类从文本文件testout.txt中读取数据。
package com.javatpoint;
import java.io.FileReader;
public class FileReaderExample {
public static void main(String args[])throws Exception{
FileReader fr=new FileReader("D:\\testout.txt");
int i;
while((i=fr.read())!=-1)
System.out.print((char)i);
fr.close();
}
}
在这里，我们假设您在“ testout.txt”文件中包含以下数据：
Welcome to javaTpoint.
输出：
Welcome to javaTpoint.