我是一名 Java 初学者,关注 java tutorials .
我正在使用 Java tutorials 中的一个简单 Java 程序的Data Streams Page ,并且在运行时,它一直显示 EOFException
。我想知道这是否正常,因为读者最终必须到达文件的末尾。
import java.io.*;
public class DataStreams {
static final String dataFile = "F://Java//DataStreams//invoicedata.txt";
static final double[] prices = { 19.99, 9.99, 15.99, 3.99, 4.99 };
static final int[] units = { 12, 8, 13, 29, 50 };
static final String[] descs = {
"Java T-shirt",
"Java Mug",
"Duke Juggling Dolls",
"Java Pin",
"Java Key Chain"
};
public static void main(String args[]) {
try {
DataOutputStream out = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(dataFile)));
for (int i = 0; i < prices.length; i ++) {
out.writeDouble(prices[i]);
out.writeInt(units[i]);
out.writeUTF(descs[i]);
}
out.close();
} catch(IOException e){
e.printStackTrace(); // used to be System.err.println();
}
double price;
int unit;
String desc;
double total = 0.0;
try {
DataInputStream in = new DataInputStream(new BufferedInputStream(new FileInputStream(dataFile)));
while (true) {
price = in.readDouble();
unit = in.readInt();
desc = in.readUTF();
System.out.format("You ordered %d" + " units of %s at $%.2f%n",
unit, desc, price);
total += unit * price;
}
} catch(IOException e) {
e.printStackTrace();
}
System.out.format("Your total is %f.%n" , total);
}
}
它编译得很好,但输出是:
You ordered 12 units of Java T-shirt at $19.99
You ordered 8 units of Java Mug at $9.99
You ordered 13 units of Duke Juggling Dolls at $15.99
You ordered 29 units of Java Pin at $3.99
You ordered 50 units of Java Key Chain at $4.99
java.io.EOFException
at java.io.DataInputStream.readFully(Unknown Source)
at java.io.DataInputStream.readLong(Unknown Source)
at java.io.DataInputStream.readDouble(Unknown Source)
at DataStreams.main(DataStreams.java:39)
Your total is 892.880000.
来自 Java tutorials的Data Streams Page ,它说:
Notice that DataStreams detects an end-of-file condition by catching EOFException, instead of testing for an invalid return value. All implementations of DataInput methods use EOFException instead of return values.
那么,这是否意味着捕获EOFException
是正常的,所以只捕获它而不处理它就可以了,意味着到达文件末尾?
如果这意味着我应该处理它,请告诉我如何处理。
编辑
根据建议,我已将 in.available() > 0
用于 while
循环条件。
或者,我无法处理异常,因为它很好。
最佳答案
从文件中读取时,您并没有终止循环。因此,它读取了所有值并正确在下一次读取迭代中抛出 EOFException 如下行:
price = in.readDouble();
如果您阅读文档,它会说:
Throws:
EOFException - if this input stream reaches the end before reading eight bytes.
IOException - the stream has been closed and the contained input stream does not support reading after close, or another I/O error occurs.
在您的 while 循环中添加适当的终止条件以解决问题,例如下面:
while(in.available() > 0) <--- if there are still bytes to read
关于java - EOFException - 如何处理?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18451232/