我有一个 java 程序，它使用执行器和线程池 ping 一个 IP 地址列表，并将结果打印在屏幕上。
它在 Windows 环境中工作正常，但是当我在 Linux 中运行它时，我经常收到“java.io.IOException:流已关闭”错误。但不适用于所有线程。
Name_49: xxx.xxx.xxx.3: 2.558
Name_50: xxx.xxx.xxx.56: 0.419
Name_44: Endsjava.io.IOException: Stream closed
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)
at java.io.BufferedInputStream.read(BufferedInputStream.java:325)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
这是我的主要行动:
ArrayList<String> ips= new ArrayList<>();
elements.add("123.123.123.123");
// etc..
ExecutorService executor = (ExecutorService) Executors.newCachedThreadPool();
List<Task> taskList = new ArrayList<>();
for (int i = 0; i < ips.size(); i++) {
Task task = new Task("Name_"+ i, elements.get(i));
taskList.add(task);
}
List<Future<Result>> resultList = null;
try {
resultList = executor.invokeAll(taskList);
} catch (InterruptedException e) {
e.printStackTrace();
}
executor.shutdown();
System.out.println("Main: Printing the results");
for (int i = 0; i < resultList.size(); i++) {
Future<Result> future = resultList.get(i);
try {
Result result = future.get();
System.out.println(result.getName() + ": " + result.getIP() + ": " + result.getPing() );
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
ping 发生在带有结果对象的可调用类中:
public class Task implements Callable<Result> {
private String name;
private String ping;
private String ip;
public Task(String name, String ip) {
this.name = name;
this.ip = ip;
}
@Override
public Result call() throws Exception {
System.out.printf("%s: Starting\n", this.name);
Result result = new Result();
String resultstr = linuxPingServer(this.ip);
//String resultstr = winPingServer(this.ip);
result.setName(this.name);
result.setIP(this.ip);
result.setPing(resultstr);
System.out.println(this.name + ": Ends");
return result;
}
private String runCMD(String cmd) {
Process p = null;
ReadStream s1 = null;
ReadStream s2 = null;
String outerr = "";
String outstd = "";
String output = "";
try {
p = Runtime.getRuntime().exec(cmd);
s1 = new ReadStream("stdin", p.getInputStream());
s2 = new ReadStream("stderr", p.getErrorStream());
s1.start();
s2.start();
p.waitFor();
//s2.returnOut();
outstd = s1.returnOut();
outerr = s2.returnOut();
if (outstd != null && !outstd.isEmpty()) {
output = outstd;
} else //if (outerr != null && !outerr.isEmpty())
{
output = outerr;
}
} catch (IOException | InterruptedException ex) {
System.out.println("StreamCheck_Exception - BashExec" + ex.getMessage());
} finally {
if (p != null) {
p.destroy();
}
}
return output;
}
public String linuxPingServer(String ip) {
// Ping with reduced interval ( -i 0.1secs)
// ping count = 5
String pingCMD = "ping -i 0.1 -c5 " + ip;
String result1 = "";
String result2 = "";
String result3 = "";
result1 = runCMD(pingCMD);
// split string on end of line
String[] lines = result1.split(System.getProperty("line.separator"));
// get statistics ( ussually last line )
result2 = lines[lines.length - 1];
// parse result -avg is third value ( fifth "/" )
lines = result2.split("/");
result3 = lines[4];
return result3;
}
这是我的读者类别:
public class ReadStream implements Runnable {
String name;
InputStream is;
Thread thread;
StringBuffer output;
public ReadStream(String name, InputStream is) {
this.name = name;
this.is = is;
this.output = new StringBuffer();
}
public void start () {
thread = new Thread (this);
thread.start ();
}
public void run () {
try {
InputStreamReader isr = new InputStreamReader (is);
BufferedReader br = new BufferedReader (isr);
while (true) {
String s = br.readLine ();
if (s == null) break;
this.output.append(s + "\n");
}
is.close ();
} catch (Exception ex) {
System.out.println ("Problem reading stream " + name + "... :" + ex);
ex.printStackTrace ();
}
}
我很困惑为什么会发生这种情况。有人可以向我解释一下我正在执行的操作有什么问题吗？
已编辑 - 更多跟踪 -
java -jar WinThreadPing.jar
Name_0: Starting
Name_52: Starting
Name_50: Starting
Name_51: Starting
Name_53: Starting
Name_48: Starting
Name_47: Starting
//.. more Starting threads
Name_98: Staring
Name_99: Staring
Name_59: Ends
Name_57: Ends
Name_60: Ends
Name_56: Ends
Name_45: Ends
Name_50: Ends
Name_48: Ends
Name_51: Ends
Name_39: Ends
Name_52: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_43: Ends
java.io.IOException: Stream closedName_53: Ends
Name_42: Ends
Name_38: Ends
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)
Name_47: Ends at java.io.BufferedInputStream.read(BufferedInputStream.java:325)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
Problem reading stream stdin... :java.io.IOException: Stream closed 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)
Name_34: Ends at java.io.BufferedReader.readLine(BufferedReader.java:382)
at WinThreadedPing.ReadStream.run(ReadStream.java:40)
at java.lang.Thread.run(Thread.java:745)
java.io.IOException: Stream closedName_36: Ends
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:272)
at java.io.BufferedInputStream.read(BufferedInputStream.java:334)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:283)
Problem reading stream stdin... :java.io.IOException: Stream closed 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)
Name_44: Ends at java.io.BufferedReader.readLine(BufferedReader.java:382)
at WinThreadedPing.ReadStream.run(ReadStream.java:40)
at java.lang.Thread.run(Thread.java:745)
java.io.IOException: Stream closed
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:272)
at java.io.BufferedInputStream.read(BufferedInputStream.java:334)
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)
Name_46: Ends
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:154)Name_29: Ends
at java.io.BufferedReader.readLine(BufferedReader.java:317)
at java.io.BufferedReader.readLine(BufferedReader.java:382)
at WinThreadedPing.ReadStream.run(ReadStream.java:40)
at java.lang.Thread.run(Thread.java:745)
Name_27: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_26: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_22: Ends
Name_28: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
java.io.IOException: Stream closed
Problem reading stream stdin... :java.io.IOException: Stream closed
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)Problem reading stream stdin... :java.io.IOException: Stream closed
at java.io.BufferedInputStream.read(BufferedInputStream.java:325)Name_23: Ends
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)Problem reading stream stdin... :java.io.IOException: Stream closed
at java.io.InputStreamReader.read(InputStreamReader.java:184)
Name_17: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_15: Ends
Name_18: Ends
Name_16: Ends
at java.io.BufferedReader.fill(BufferedReader.java:154)
at java.io.BufferedReader.readLine(BufferedReader.java:317)
Problem reading stream stdin... :java.io.IOException: Stream closed
at java.io.BufferedReader.readLine(BufferedReader.java:382)
Name_20: Ends at WinThreadedPing.ReadStream.run(ReadStream.java:40)
Name_14: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Problem reading stream stdin... :java.io.IOException: Stream closed
at java.lang.Thread.run(Thread.java:745)Name_10: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_19: Endsjava.io.IOException: Stream closed
Name_7: Ends
Name_8: Ends
at java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:162)
at java.io.BufferedInputStream.read(BufferedInputStream.java:325)
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)
Name_11: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_4: Ends
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_5: Ends 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 WinThreadedPing.ReadStream.run(ReadStream.java:40)
at java.lang.Thread.run(Thread.java:745)
Problem reading stream stdin... :java.io.IOException: Stream closed
Name_62: Ends
//..etc
最佳答案
我正在回答我自己的问题。
经过一些实验，我能够使用 ProcessBuilder 纠正该问题。以及 ProcessBuilder OpenFiles 的答案问题:
ProcessBuilder pb = new ProcessBuilder("bash", "-c", cmd);
pb.redirectError(new File(this.Filepath + ".err"));
pb.redirectOutput(new File(this.Filepath));
Process shell = pb.start();
//shell.wait();
int exitVal= shell.waitFor();
//missing these was causing the mass amounts of open 'files'
shell.getInputStream().close();
shell.getOutputStream().close();
shell.getErrorStream().close();
关于java - 为什么我在 Linux 中使用 ExecutorService 读取线程流时得到 "java.io.IOException: Stream closed"？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28409132/