我有一个 xmlStream,我正在使用 org.apache.wink.json4j.utils.XML 将其转换为 jsonStream。这是代码
public void process(InputStream xmlStream) {
final BufferedInputStream bufferedXmlStream = new BufferedInputStream(xmlStream);
PipedInputStream pipedJsonInputStream = new PipedInputStream();
final PipedOutputStream jsonStream = new PipedOutputStream(pipedJsonInputStream);
Thread xmlToJsonThread = new Thread(new Runnable() {
@Override
public void run() {
// put your code that writes data to the outputstream here.
try {
XML.toJson(bufferedXmlStream, jsonStream, true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
xmlToJsonThread.setDaemon(true);
xmlToJsonThread.start();
//process data from piped stream
BufferedReader reader = new BufferedReader(new InputStreamReader(
pipedJsonInputStream, StandardCharsets.UTF_8));
try {
// use reader to further process json in main thread...
parseJsonStream(reader);
} finally {
reader.close();
jsonStream.close();
}
}
当 XML.toJson 抛出异常时,我看到主线程没有退出。 我该如何处理这个问题? 你们认为这是将 XML 流转换为 Json 流以进行进一步处理的好方法吗?我真的很感激任何建议。多谢!
最佳答案
问题是子线程上的异常需要报告回主线程。除非您将读取器和写入器放在单独的线程中,否则这可能会很棘手。
我这样做的方法是将这两部分包装在 ExecutionCompletionService
中 - 像这样:
public void process(InputStream xmlStream) {
ExecutorService threadPool = Executors.newFixedThreadPool(2);
ExecutorCompletionService<Void> ecs = new ExecutorCompletionService<>(threadPool);
final BufferedInputStream bufferedXmlStream = new BufferedInputStream(xmlStream);
PipedInputStream pipedJsonInputStream = new PipedInputStream();
final PipedOutputStream jsonStream = new PipedOutputStream(pipedJsonInputStream);
ecs.submit( new Callable<Void>() {
@Override
public Void call() {
// put your code that writes data to the outputstream here.
try {
XML.toJson(bufferedXmlStream, jsonStream, true);
} catch (Exception e) {
e.printStackTrace();
throw e;
}
return null;
}
});
ecs.submit( new Callable<Void>() {
@Override
public Void call() {
try {
// use reader to further process json in main thread...
parseJsonStream(reader);
} finally {
reader.close();
jsonStream.close();
}
return null;
}
});
// Wait for all tasks to be done.
// Kill the other thread if one hits an exception.
try {
for (int i = 0; i < 2; ++i) {
ecs.take().get();
}
} finally {
threadPool.shutdownNow();
}
}
关于java - 处理 java 管道流中的异常,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29107210/