在方法getFileName()中创建对象BufferedReader并将对象的引用分配给变量reader。然后流在终于关闭。关闭后为何不打开流?
然后调用方法readStringsFromConsole()。有创建相同的对象。但抛出IOException。为什么发生?
PS:对不起,我的英语:)
堆栈跟踪:
java.io.IOException: Stream closed
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:170)
at java.io.BufferedInputStream.read(BufferedInputStream.java:336)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:161)
at java.io.BufferedReader.readLine(BufferedReader.java:324)
at java.io.BufferedReader.readLine(BufferedReader.java:389)
at com.test.home04.Solution.readStringsFromConsole(Solution.java:55)
代码:
import java.io.*;
import java.util.*;
public class Solution
{
public static void main(String[] args)
{
String fileName = getFileName();
ArrayList<String> listStrings = readStringsFromConsole();
writeToFileFromList(fileName, listStrings);
}
public static void writeToFileFromList (String fileName, ArrayList<String> listInputString)
{
PrintWriter writer = null;
try {
writer = new PrintWriter(fileName, "UTF-8");
for (String stringItem : listInputString)
writer.write(stringItem);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (writer != null)
writer.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
public static ArrayList<String> readStringsFromConsole() {
BufferedReader reader = null;
ArrayList<String> listInputString = new ArrayList<String>();
String line = null;
try {
reader = new BufferedReader(new InputStreamReader(System.in));
while (true)
{
line = reader.readLine();
if ("exit".equals(line))
break;
listInputString.add(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null)
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
return listInputString;
}
}
public static String getFileName()
{
BufferedReader reader = null;
String fileName = null;
try {
reader = new BufferedReader(new InputStreamReader(System.in));
while (fileName == null) {
fileName = reader.readLine();
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null)
reader.close();
} catch (Exception e) {
e.printStackTrace();
}
return fileName;
}
}
}
封闭的流不能重新打开。您必须在每次完全读完文件时使用新的FileInputStream或FileReader重新打开该文件 – ControlAltDel