Java RandomAccessFile readInt（）方法与示例

RandomAccessFile类readInt()方法 (RandomAccessFile Class readInt() method)

readInt() method is available in java.io package.
readInt()方法在java.io包中可用。
readInt() method is used to read signed 32-bit integer value from this RandomAccessFile.
readInt()方法用于从此RandomAccessFile读取带符号的32位整数值。
readInt() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
readInt()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。
readInt() method may throw an exception at the time of reading integer.
readInt()方法在读取整数时可能会引发异常。
- IOException: This exception may throw an exception while performing input/output operation.IOException ：在执行输入/输出操作时，此异常可能会引发异常。
- EOFException: This exception may throw when the file pointer reaches EOF (End-Of-File) before reading 4 bytes.EOFException ：当文件指针在读取4个字节之前到达EOF(文件末尾)时，可能引发此异常。

Syntax:

句法：

    public final int readInt();

Parameter(s):

参数：

It does not accept any parameter.
它不接受任何参数。

Return value:

返回值：

The return type of this method is int, it returns the 4 bytes of data from this RandomAccessFile manipulated as an int value.

此方法的返回类型为int ，它从作为Random值操纵的RandomAccessFile中返回4个字节的数据。

Example:

例：

// Java program to demonstrate the example 
// of int readInt() method of
// RandomAccessFile
import java.io.*;
class RAFReadInt {
public static void main(String[] args) throws Exception {
// Instantiate a random access file
// object with file name and permissions
RandomAccessFile ra_f = new RandomAccessFile("e:/includehelp.txt", "rw");
// By using writeFloat() method is to 
// write float to the file
ra_f.writeInt(500);
// Initially set the file pointer
// is at 1 for reading the file
ra_f.seek(1);
// By using readInt() method is to 
// read int upto signed 4 bytes 
// from the file
int i = ra_f.readInt();
System.out.println("ra_f.readInt(): " + i);
// By using close() method isto
// close this stream ran_f
ra_f.close();
}
}

Output

输出量