在Java IOException Premature EOF中阅读网页

Question

阅读网页时，我经常收到“过早的EOF”异常。

以下是StackTrace

java.io.IOException: Premature EOF
    at sun.net.www.http.ChunkedInputStream.readAheadBlocking(ChunkedInputStream.java:556)
    at sun.net.www.http.ChunkedInputStream.readAhead(ChunkedInputStream.java:600)
    at sun.net.www.http.ChunkedInputStream.read(ChunkedInputStream.java:687)
    at java.io.FilterInputStream.read(FilterInputStream.java:133)
    at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(HttpURLConnection.java:2968)
    at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
    at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:325)
    at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:177)
    at java.io.InputStreamReader.read(InputStreamReader.java:184)
    at java.io.BufferedReader.fill(BufferedReader.java:154)
    at java.io.BufferedReader.readLine(BufferedReader.java:317)
    at java.io.BufferedReader.readLine(BufferedReader.java:382)
    at Utilities.getPage(Utilities.java:24)  while ((line = rd.readLine()) != null) {
    at TalkPage.<init>(TalkPage.java:15)
    at Updater.run(Updater.java:65)

以下是getPage（）方法

public static String getPage(String urlString) throws Exception {
    URL url = new URL(urlString);
    URLConnection conn = url.openConnection();
    BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    StringBuffer sb = new StringBuffer();
    String line;
    while ((line = rd.readLine()) != null) {  // LINE 24
        sb.append(line);
    }
    return sb.toString();
}

什么是持久性EOFException？为什么在这种特殊情况下会发生这种情况？如何避免呢？

其他一些信息：正在读取的页面大小约为20 KB，并且我正在程序中读取许多此类页面（大约20 000）

Answer 1

这可能是因为您正在逐行读取内容，而对于最后一行，文件可能缺少返回值以表示行结束。将此替换为：

int BUFFER_SIZE=1024;
char[] buffer = new char[BUFFER_SIZE]; // or some other size, 
int charsRead = 0;
while ( (charsRead  = rd.read(buffer, 0, BUFFER_SIZE)) != -1) {
  sb.append(buffer, 0, charsRead);
}