Issue #12775 avoid unneccesary exception in getInputStream

Author: janbartel

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/ServletApiRequest.java

@@ -63,6 +63,7 @@
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFields;
 import org.eclipse.jetty.http.HttpHeader;
+import org.eclipse.jetty.http.HttpHeaderValue;
 import org.eclipse.jetty.http.HttpStatus;
 import org.eclipse.jetty.http.HttpURI;
 import org.eclipse.jetty.http.HttpVersion;
@@ -916,9 +917,12 @@ public ServletInputStream getInputStream() throws IOException
     {
         if (_inputState != ServletContextRequest.INPUT_NONE && _inputState != ServletContextRequest.INPUT_STREAM)
             throw new IllegalStateException("READER");
+
+        // Try to write a 100 continue if it is necessary
+        if (_inputState == ServletContextRequest.INPUT_NONE && _servletContextRequest.getHeaders().contains(HttpHeader.EXPECT, HttpHeaderValue.CONTINUE.asString()))
+            _servletChannel.getResponse().writeInterim(HttpStatus.CONTINUE_100, HttpFields.EMPTY);
+
         _inputState = ServletContextRequest.INPUT_STREAM;
-        // Try to write a 100 continue, ignoring failure result if it was not necessary.
-        _servletChannel.getResponse().writeInterim(HttpStatus.CONTINUE_100, HttpFields.EMPTY);
         return getServletRequestInfo().getHttpInput();
     }
 

jetty-ee9/jetty-ee9-nested/src/main/java/org/eclipse/jetty/ee9/nested/Request.java

@@ -912,9 +912,12 @@ public ServletInputStream getInputStream() throws IOException
     {
         if (_inputState != INPUT_NONE && _inputState != INPUT_STREAM)
             throw new IllegalStateException("READER");
+
+        // Try to write a 100 continue if it is necessary.
+        if (_inputState == INPUT_NONE && _coreRequest.getHeaders().contains(HttpHeader.EXPECT, HttpHeaderValue.CONTINUE.asString()))
+            _channel.getCoreResponse().writeInterim(HttpStatus.CONTINUE_100, HttpFields.EMPTY);
+
         _inputState = INPUT_STREAM;
-        // Try to write a 100 continue, ignoring failure result if it was not necessary.
-        _channel.getCoreResponse().writeInterim(HttpStatus.CONTINUE_100, HttpFields.EMPTY);
         return _input;
     }