我使用REST API从硬件键盘获取输入。我想知道如果有输入，如何继续阅读InputStream，然后优雅地停止而不会抛出SocketTimoutException。
我的代码
// Start a new thread for reading the keyboard input
new Thread(new Runnable() {
@Override
public void run() {
InputStream inputStream = null;
try {
// Set byte stream from response body
inputStream = response.body().byteStream();
// I THINK THIS IS THE PROBLEM. WHILE (TRUE) //
while (true) {
// This is where the rest response is read into an array of bytes. I interpret this array below and it seems to work as intended.
final byte[] buffer = new byte[256];
int bytesRead = inputStream.read(buffer, 0, buffer.length);
// This was more for debugging purposes... it never get invoked, as far as I can tell.
if (bytesRead < 0) {
Log.w(TAG, "...Returning. 0 bytes read.");
return;
}
// I'll specify what a response looks like below this code block.
String fullResponse = new String(buffer, StandardCharsets.UTF_8);
Log.v(TAG, "...Full rest response : \n " + fullResponse);
// This processes the response, narrowing down to just the keycode. This works as it's supposed to.
processResponse(fullResponse);
}
} catch (IOException e) {
e.printStackTrace();
Log.v(TAG, "...Problem reading input stream");
} finally {
// Close input stream when I'm done with it.
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}).start();
所以这是我从其他api得到的响应的一个例子。我的processResponse()方法使用我按下的密钥代码（在本例中为34）查找并更新文本视图。这是按预期工作的。
...Full rest response :
timeout: 2000000
event: keypress
id: 1492005344
data: {"device":"keyboard","pressedKeycodes":"34 "}
我想知道的是，只要有东西存在，如何继续阅读InputStream，并且在没有抛出SockoutTimeoutException之后不再接收输入后停止。如果我不这样做while(true)我没有得到例外，但它只能读取一个按键盘。
以下是例外：
04-12 15:18:02.467 7585-7810/com.accutime.restpractice W/System.err: java.net.SocketTimeoutException
04-12 15:18:02.469 7585-7810/com.accutime.restpractice W/System.err: at java.net.PlainSocketImpl.read(PlainSocketImpl.java:488)
04-12 15:18:02.470 7585-7810/com.accutime.restpractice W/System.err: at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:37)
04-12 15:18:02.471 7585-7810/com.accutime.restpractice W/System.err: at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:237)
04-12 15:18:02.472 7585-7810/com.accutime.restpractice W/System.err: at okio.Okio$2.read(Okio.java:140)
04-12 15:18:02.473 7585-7810/com.accutime.restpractice W/System.err: at okio.AsyncTimeout$2.read(AsyncTimeout.java:238)
04-12 15:18:02.474 7585-7810/com.accutime.restpractice W/System.err: at okio.RealBufferedSource.request(RealBufferedSource.java:66)
04-12 15:18:02.475 7585-7810/com.accutime.restpractice W/System.err: at okio.RealBufferedSource.require(RealBufferedSource.java:59)
04-12 15:18:02.476 7585-7810/com.accutime.restpractice W/System.err: at okio.RealBufferedSource.readHexadecimalUnsignedLong(RealBufferedSource.java:284)
04-12 15:18:02.477 7585-7810/com.accutime.restpractice W/System.err: at okhttp3.internal.http.Http1xStream$ChunkedSource.readChunkSize(Http1xStream.java:441)
04-12 15:18:02.478 7585-7810/com.accutime.restpractice W/System.err: at okhttp3.internal.http.Http1xStream$ChunkedSource.read(Http1xStream.java:422)
04-12 15:18:02.479 7585-7810/com.accutime.restpractice W/System.err: at okio.RealBufferedSource.read(RealBufferedSource.java:45)
04-12 15:18:02.479 7585-7810/com.accutime.restpractice W/System.err: at okio.ForwardingSource.read(ForwardingSource.java:35)
04-12 15:18:02.480 7585-7810/com.accutime.restpractice W/System.err: at retrofit2.OkHttpCall$ExceptionCatchingRequestBody$1.read(OkHttpCall.java:279)
04-12 15:18:02.481 7585-7810/com.accutime.restpractice W/System.err: at okio.RealBufferedSource$1.read(RealBufferedSource.java:386)
04-12 15:18:02.482 7585-7810/com.accutime.restpractice W/System.err: at com.accutime.restpractice.MainActivity$1$1.run(MainActivity.java:172)
04-12 15:18:02.483 7585-7810/com.accutime.restpractice W/System.err: at java.lang.Thread.run(Thread.java:818)
答案 0 :(得分：0)
首先，我将创建一个读取InputStream并返回byte[]内容读取的实用程序类。假设在此示例中，实用程序类称为InputOutputStreams。
我的方法将是：
public static byte[] readFully(InputStream input) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[256];
int totalBytesRead = 0;
int bytesRead = 0;
while (input.read(buffer) > 0) {
baos.write(buffer, 0, bytesRead);
}
return baos.toByteArray();
}
然后我将删除您拥有的while循环（以及各种实现），并使用上面实现的实用程序类来检索InputStream的内容，如下所示：
// Start a new thread for reading the keyboard input
new Thread(new Runnable() {
@Override
public void run() {
InputStream inputStream = null;
try {
// Set byte stream from response body
inputStream = response.body().byteStream();
// I'll specify what a response looks like below this code block.
//THIS IS WHERE I USE THE UTILITY CLASS
String fullResponse = new String(InputOutputStreams.readFully(inputStream), StandardCharsets.UTF_8);
Log.v(TAG, "...Full rest response : \n " + fullResponse);
// This processes the response, narrowing down to just the keycode. This works as it's supposed to.
processResponse(fullResponse);
} catch (IOException e) {
e.printStackTrace();
Log.v(TAG, "...Problem reading input stream");
} finally {
// Close input stream when I'm done with it.
if (inputStream != null) {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}).start();
我希望这会有所帮助......
答案 1 :(得分：0)
我找到了解决问题的方法。问题正文中的代码可以保持不变，但是当我创建改造构建器时，我需要添加一个read timeout和write timeout max value的OkHttpClient。
这导致程序不会超时SocketNotFound异常，并且很快就会接受输入。
这是我的代码：
// TODO 9 : Set a timeout for the connection // <- I NEEDED TO ADD THIS BLOCK ***
OkHttpClient okHttpClient = new OkHttpClient().newBuilder()
.readTimeout(Integer.MAX_VALUE, TimeUnit.MILLISECONDS)
.writeTimeout(Integer.MAX_VALUE, TimeUnit.MILLISECONDS)
.build();
// TODO 7 : Create retrofit builder
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(ClockAPI.ENDPOINT) // Refers to endpoint defined in GithubAPI
.addConverterFactory(GsonConverterFactory.create(gson)) // Refers to gson builder, created
.client(okHttpClient) // <- AND THIS LINE ***
.build();
// TODO 8 : Create REST API through retrofit builder
clockUserAPI = retrofit.create(ClockAPI.class);