/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.coyote.http2;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import jakarta.servlet.AsyncContext;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.junit.Assert;
import org.junit.Test;
import org.apache.catalina.Context;
import org.apache.catalina.Wrapper;
import org.apache.catalina.connector.Connector;
import org.apache.catalina.connector.ResponseFacade;
import org.apache.catalina.startup.Tomcat;
import org.apache.tomcat.util.compat.JrePlatform;
import org.apache.tomcat.util.http.FastHttpDateFormat;
import org.apache.tomcat.util.http.Method;
public class TestStreamProcessor extends Http2TestBase {
@Test
public void testAsyncComplete() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
// Map the async servlet to /simple so we can re-use the HTTP/2 handling
// logic from the super class.
Context ctxt = getProgrammaticRootContext();
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Wrapper w = Tomcat.addServlet(ctxt, "async", new AsyncComplete());
w.setAsyncSupported(true);
ctxt.addServletMappingDecoded("/async", "async");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
buildGetRequest(frameHeader, headersPayload, null, 3, "/async");
writeFrame(frameHeader, headersPayload);
readSimpleGetResponse();
// Flush before startAsync means body is written in two packets so an
// additional frame needs to be read
parser.readFrame();
Assert.assertEquals("3-HeadersStart " + "3-Header-[:status]-[200] " +
"3-Header-[content-type]-[text/plain;charset=UTF-8] " +
"3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] " + "3-HeadersEnd " + "3-Body-17 " + "3-Body-8 " +
"3-EndOfStream ", output.getTrace());
}
@Test
public void testAsyncDispatch() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
// Map the async servlet to /simple so we can re-use the HTTP/2 handling
// logic from the super class.
Context ctxt = getProgrammaticRootContext();
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Wrapper w = Tomcat.addServlet(ctxt, "async", new AsyncDispatch());
w.setAsyncSupported(true);
ctxt.addServletMappingDecoded("/async", "async");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
buildGetRequest(frameHeader, headersPayload, null, 3, "/async");
writeFrame(frameHeader, headersPayload);
readSimpleGetResponse();
Assert.assertEquals(getSimpleResponseTrace(3), output.getTrace());
}
@Test
public void testPrepareHeaders() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
File appDir = new File("test/webapp");
Context ctxt = tomcat.addWebapp(null, "", appDir.getAbsolutePath());
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(3);
headers.add(new Header(":method", Method.GET));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/index.html"));
headers.add(new Header(":authority", "localhost:" + getPort()));
headers.add(new Header("if-modified-since", FastHttpDateFormat.getCurrentDate()));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
parser.readFrame();
StringBuilder expected = new StringBuilder();
expected.append("3-HeadersStart ");
expected.append("3-Header-[:status]-[304] ");
// Different line-endings -> different files size -> different weak eTag
if (JrePlatform.IS_WINDOWS) {
expected.append("3-Header-[etag]-[W/\"957-1447269522000\"] ");
} else {
expected.append("3-Header-[etag]-[W/\"934-1447269522000\"] ");
}
expected.append("3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] ");
expected.append("3-HeadersEnd ");
expected.append("3-EndOfStream ");
Assert.assertEquals(expected.toString(), output.getTrace());
}
@Test
public void testPrepareHeadersNoContent() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
File appDir = new File("test/webapp");
Context ctxt = tomcat.addWebapp(null, "", appDir.getAbsolutePath());
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Tomcat.addServlet(ctxt, "noContent", new NoContentServlet());
ctxt.addServletMappingDecoded("/noContent", "noContent");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(3);
headers.add(new Header(":method", Method.GET));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/noContent"));
headers.add(new Header(":authority", "localhost:" + getPort()));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
parser.readFrame();
StringBuilder expected = new StringBuilder();
expected.append("3-HeadersStart ");
expected.append("3-Header-[:status]-[204] ");
expected.append("3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] ");
expected.append("3-HeadersEnd ");
expected.append("3-EndOfStream ");
Assert.assertEquals(expected.toString(), output.getTrace());
}
@Test
public void testValidateRequestMethod() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
File appDir = new File("test/webapp");
Context ctxt = tomcat.addWebapp(null, "", appDir.getAbsolutePath());
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(4);
headers.add(new Header(":method", "not,token"));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/index.html"));
headers.add(new Header(":authority", "localhost:" + getPort()));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
parser.readFrame();
StringBuilder expected = new StringBuilder();
expected.append("3-HeadersStart ");
expected.append("3-Header-[:status]-[400] ");
expected.append("3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] ");
expected.append("3-HeadersEnd ");
Assert.assertEquals(expected.toString(), output.getTrace());
}
@Test
public void testValidateRequestHeaderName() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
File appDir = new File("test/webapp");
Context ctxt = tomcat.addWebapp(null, "", appDir.getAbsolutePath());
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(5);
headers.add(new Header(":method", Method.GET));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/index.html"));
headers.add(new Header(":authority", "localhost:" + getPort()));
headers.add(new Header("not token", "value"));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
parser.readFrame();
StringBuilder expected = new StringBuilder();
expected.append("3-HeadersStart ");
expected.append("3-Header-[:status]-[400] ");
expected.append("3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] ");
expected.append("3-HeadersEnd ");
Assert.assertEquals(expected.toString(), output.getTrace());
}
@Test
public void testValidateRequestURI() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
File appDir = new File("test/webapp");
Context ctxt = tomcat.addWebapp(null, "", appDir.getAbsolutePath());
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(4);
headers.add(new Header(":method", Method.GET));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/index^html"));
headers.add(new Header(":authority", "localhost:" + getPort()));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
parser.readFrame();
StringBuilder expected = new StringBuilder();
expected.append("3-HeadersStart ");
expected.append("3-Header-[:status]-[400] ");
expected.append("3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] ");
expected.append("3-HeadersEnd ");
Assert.assertEquals(expected.toString(), output.getTrace());
}
@Test
public void testValidateRequestQueryString() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
File appDir = new File("test/webapp");
Context ctxt = tomcat.addWebapp(null, "", appDir.getAbsolutePath());
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(4);
headers.add(new Header(":method", Method.GET));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/index.html?foo=[]"));
headers.add(new Header(":authority", "localhost:" + getPort()));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
parser.readFrame();
StringBuilder expected = new StringBuilder();
expected.append("3-HeadersStart ");
expected.append("3-Header-[:status]-[400] ");
expected.append("3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] ");
expected.append("3-HeadersEnd ");
Assert.assertEquals(expected.toString(), output.getTrace());
}
@Test
public void testValidateRequestQueryStringRelaxed() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
File appDir = new File("test/webapp");
Context ctxt = tomcat.addWebapp(null, "", appDir.getAbsolutePath());
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
tomcat.getConnector().setProperty("relaxedQueryChars", "[]");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(4);
headers.add(new Header(":method", Method.GET));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/index.html?foo=[]"));
headers.add(new Header(":authority", "localhost:" + getPort()));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
parser.readFrame();
StringBuilder expected = new StringBuilder();
expected.append("3-HeadersStart ");
expected.append("3-Header-[:status]-[200] ");
// The status code is the most important thing to test
Assert.assertTrue(output.getTrace().startsWith(expected.toString()));
}
private static final class AsyncComplete extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/plain");
response.setCharacterEncoding("UTF-8");
PrintWriter pw = response.getWriter();
pw.print("Enter-");
final AsyncContext asyncContext = request.startAsync(request, response);
pw.print("StartAsync-");
pw.flush();
asyncContext.start(new Runnable() {
@Override
public void run() {
try {
asyncContext.getResponse().getWriter().print("Complete");
asyncContext.complete();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
private static final class AsyncDispatch extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
final AsyncContext asyncContext = request.startAsync(request, response);
asyncContext.start(new Runnable() {
@Override
public void run() {
try {
asyncContext.dispatch("/simple");
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
@Test
public void testCompression() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
Context ctxt = getProgrammaticRootContext();
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Tomcat.addServlet(ctxt, "compression", new CompressionServlet());
ctxt.addServletMappingDecoded("/compression", "compression");
// Enable compression
Connector connector = tomcat.getConnector();
Assert.assertTrue(connector.setProperty("compression", "on"));
tomcat.start();
enableHttp2();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
byte[] frameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
List<Header> headers = new ArrayList<>(3);
headers.add(new Header(":method", Method.GET));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":path", "/compression"));
headers.add(new Header(":authority", "localhost:" + getPort()));
headers.add(new Header("accept-encoding", "gzip"));
buildGetRequest(frameHeader, headersPayload, null, headers, 3);
writeFrame(frameHeader, headersPayload);
readSimpleGetResponse();
Assert.assertEquals("3-HeadersStart " + "3-Header-[:status]-[200] " + "3-Header-[vary]-[accept-encoding] " +
"3-Header-[content-encoding]-[gzip] " + "3-Header-[content-type]-[text/plain;charset=UTF-8] " +
"3-Header-[date]-[Wed, 11 Nov 2015 19:18:42 GMT] " + "3-HeadersEnd " + "3-Body-97 " +
"3-EndOfStream ", output.getTrace());
}
private static class CompressionServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// Generate content type that is compressible
resp.setContentType("text/plain");
resp.setCharacterEncoding("UTF-8");
// Make ir large enough to trigger compression
int count = 64 * 1024;
// One bytes per entry
resp.setContentLengthLong(count);
OutputStream os = resp.getOutputStream();
for (int i = 0; i < count; i++) {
os.write('X');
}
}
}
@Test
public void testConnect() throws Exception {
http2Connect();
List<Header> headers = new ArrayList<>(4);
headers.add(new Header(":method", Method.CONNECT));
headers.add(new Header(":scheme", "http"));
headers.add(new Header(":authority", "example.local"));
byte[] headersFrameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
buildGetRequest(headersFrameHeader, headersPayload, null, headers, 3);
writeFrame(headersFrameHeader, headersPayload);
parser.readFrame();
String trace = output.getTrace();
Assert.assertTrue(trace, trace.contains("3-Header-[:status]-[501]"));
}
@Test
public void testEarlyHints() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
Context ctxt = getProgrammaticRootContext();
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Tomcat.addServlet(ctxt, "ehs", new EarlyHintsServlet());
ctxt.addServletMappingDecoded("/ehs", "ehs");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
// Disable overhead protection for window update as it breaks some tests
http2Protocol.setOverheadWindowUpdateThreshold(0);
byte[] headersFrameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
buildGetRequest(headersFrameHeader, headersPayload, null, 3, "/ehs");
// Write the headers
writeFrame(headersFrameHeader, headersPayload);
parser.readFrame();
Assert.assertEquals("3-HeadersStart " + "3-Header-[:status]-[103] " +
"3-Header-[link]-[</style.css>; rel=preload; as=style] " + "3-HeadersEnd ", output.getTrace());
output.clearTrace();
parser.readFrame();
parser.readFrame();
Assert.assertEquals("3-HeadersStart " + "3-Header-[:status]-[200] " +
"3-Header-[link]-[</style.css>; rel=preload; as=style] " +
"3-Header-[content-type]-[text/plain;charset=UTF-8] " +
"3-Header-[content-length]-[2] " +
"3-Header-[date]-[" + DEFAULT_DATE + "] " + "3-HeadersEnd " + "3-Body-2 " + "3-EndOfStream ",
output.getTrace());
}
private static class EarlyHintsServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.addHeader("Link", "</style.css>; rel=preload; as=style");
((ResponseFacade) resp).sendEarlyHints();
resp.setCharacterEncoding(StandardCharsets.UTF_8);
resp.setContentType("text/plain");
resp.getWriter().write("OK");
}
}
@Test
public void testServerHeaderDefault() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
Context ctxt = getProgrammaticRootContext();
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Tomcat.addServlet(ctxt, "server", new ServerHeaderServlet());
ctxt.addServletMappingDecoded("/server", "server");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
// Disable overhead protection for window update as it breaks some tests
http2Protocol.setOverheadWindowUpdateThreshold(0);
byte[] headersFrameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
buildGetRequest(headersFrameHeader, headersPayload, null, 3, "/server");
// Write the headers
writeFrame(headersFrameHeader, headersPayload);
parser.readFrame();
parser.readFrame();
Assert.assertEquals("3-HeadersStart " + "3-Header-[:status]-[200] " +
"3-Header-[server]-[TestServerApp] " +
"3-Header-[content-type]-[text/plain;charset=UTF-8] " +
"3-Header-[content-length]-[2] " +
"3-Header-[date]-[" + DEFAULT_DATE + "] " + "3-HeadersEnd " + "3-Body-2 " + "3-EndOfStream ",
output.getTrace());
}
@Test
public void testServerHeaderRemove() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
tomcat.getConnector().setProperty("serverRemoveAppProvidedValues", "true");
Context ctxt = getProgrammaticRootContext();
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Tomcat.addServlet(ctxt, "server", new ServerHeaderServlet());
ctxt.addServletMappingDecoded("/server", "server");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
// Disable overhead protection for window update as it breaks some tests
http2Protocol.setOverheadWindowUpdateThreshold(0);
byte[] headersFrameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
buildGetRequest(headersFrameHeader, headersPayload, null, 3, "/server");
// Write the headers
writeFrame(headersFrameHeader, headersPayload);
parser.readFrame();
parser.readFrame();
Assert.assertEquals("3-HeadersStart " + "3-Header-[:status]-[200] " +
"3-Header-[content-type]-[text/plain;charset=UTF-8] " +
"3-Header-[content-length]-[2] " +
"3-Header-[date]-[" + DEFAULT_DATE + "] " + "3-HeadersEnd " + "3-Body-2 " + "3-EndOfStream ",
output.getTrace());
}
@Test
public void testServerHeaderForce() throws Exception {
enableHttp2();
Tomcat tomcat = getTomcatInstance();
Context ctxt = getProgrammaticRootContext();
Tomcat.addServlet(ctxt, "simple", new SimpleServlet());
ctxt.addServletMappingDecoded("/simple", "simple");
Tomcat.addServlet(ctxt, "server", new ServerHeaderServlet());
ctxt.addServletMappingDecoded("/server", "server");
tomcat.start();
openClientConnection();
doHttpUpgrade();
sendClientPreface();
validateHttp2InitialResponse();
/*
* This adds the server header to every response. Set this after the initial response has been validated to
* avoid having to update the validation code to account for the additional server header.
*/
tomcat.getConnector().setProperty("server", "TestServerForce");
// Disable overhead protection for window update as it breaks some tests
http2Protocol.setOverheadWindowUpdateThreshold(0);
byte[] headersFrameHeader = new byte[9];
ByteBuffer headersPayload = ByteBuffer.allocate(128);
buildGetRequest(headersFrameHeader, headersPayload, null, 3, "/server");
// Write the headers
writeFrame(headersFrameHeader, headersPayload);
parser.readFrame();
parser.readFrame();
Assert.assertEquals("3-HeadersStart " + "3-Header-[:status]-[200] " +
"3-Header-[server]-[TestServerForce] " +
"3-Header-[content-type]-[text/plain;charset=UTF-8] " +
"3-Header-[content-length]-[2] " +
"3-Header-[date]-[" + DEFAULT_DATE + "] " + "3-HeadersEnd " + "3-Body-2 " + "3-EndOfStream ",
output.getTrace());
}
private static class ServerHeaderServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.addHeader("server", "TestServerApp");
resp.setCharacterEncoding(StandardCharsets.UTF_8);
resp.setContentType("text/plain");
resp.getWriter().write("OK");
}
}
}