Index: trunk/test/functional/org/openstreetmap/josm/tools/HttpClientTest.java
===================================================================
--- trunk/test/functional/org/openstreetmap/josm/tools/HttpClientTest.java	(revision 9255)
+++ trunk/test/functional/org/openstreetmap/josm/tools/HttpClientTest.java	(revision 9255)
@@ -0,0 +1,140 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.tools;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.nullValue;
+import static org.junit.Assert.assertThat;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+
+import javax.json.JsonObject;
+import javax.json.JsonReader;
+import javax.json.spi.JsonProvider;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.openstreetmap.josm.JOSMFixture;
+import org.openstreetmap.josm.data.Version;
+
+/**
+ * Tests the {@link HttpClient} using the webservice <a href="https://httpbin.org/">https://httpbin.org/</a>.
+ */
+public class HttpClientTest {
+
+    @BeforeClass
+    public static void setUpBeforeClass() {
+        JOSMFixture.createFunctionalTestFixture().init();
+    }
+
+    @Test
+    public void testConstructorGetterSetter() throws Exception {
+        final HttpClient client = HttpClient.create(new URL("https://httpbin.org/"));
+        assertThat(client.getURL(), is(new URL("https://httpbin.org/")));
+        assertThat(client.getRequestMethod(), is("GET"));
+        assertThat(client.getRequestHeader("Accept"), nullValue());
+        client.setAccept("text/html");
+        assertThat(client.getRequestHeader("Accept"), is("text/html"));
+        assertThat(client.getRequestHeader("ACCEPT"), is("text/html"));
+        client.setHeaders(Collections.singletonMap("foo", "bar"));
+        assertThat(client.getRequestHeader("foo"), is("bar"));
+        client.setHeaders(Collections.singletonMap("foo", "baz"));
+        assertThat(client.getRequestHeader("foo"), is("baz"));
+        client.setHeaders(Collections.singletonMap("foo", (String) null));
+        assertThat(client.getRequestHeader("foo"), nullValue());
+    }
+
+    @Test
+    public void testGet() throws Exception {
+        final HttpClient.Response response = HttpClient.create(new URL("https://httpbin.org/get?foo=bar")).connect();
+        assertThat(response.getRequestMethod(), is("GET"));
+        assertThat(response.getResponseCode(), is(200));
+        assertThat(response.getResponseMessage(), is("OK"));
+        assertThat(response.getContentType(), is("application/json"));
+        assertThat(response.getHeaderField("Content-Type"), is("application/json"));
+        assertThat(response.getHeaderField("Content-TYPE"), is("application/json"));
+        assertThat(response.getHeaderFields().get("Content-Type"), is(Collections.singletonList("application/json")));
+        assertThat(response.getHeaderFields().get("Content-TYPE"), nullValue());
+        try (final InputStream in = response.getContent();
+             final JsonReader json = JsonProvider.provider().createReader(in)) {
+            final JsonObject root = json.readObject();
+            assertThat(root.getJsonObject("args").getString("foo"), is("bar"));
+            assertThat(root.getString("url"), is("https://httpbin.org/get?foo=bar"));
+        }
+    }
+
+    @Test
+    public void testUserAgent() throws Exception {
+        try (final InputStream in = HttpClient.create(new URL("https://httpbin.org/user-agent")).connect().getContent();
+             final JsonReader json = JsonProvider.provider().createReader(in)) {
+            assertThat(json.readObject().getString("user-agent"), is(Version.getInstance().getFullAgentString()));
+        }
+    }
+
+    @Test
+    public void testFetchUtf8Content() throws Exception {
+        final HttpClient.Response response = HttpClient.create(new URL("https://httpbin.org/encoding/utf8")).connect();
+        assertThat(response.getResponseCode(), is(200));
+        final String content = response.fetchContent();
+        assertThat(content, containsString("UTF-8 encoded sample plain-text file"));
+        assertThat(content, containsString("\u2200x\u2208\u211d:"));
+    }
+
+    @Test
+    public void testPost() throws Exception {
+        final String text = "Hello World!\nGeetings from JOSM, the Java OpenStreetMap Editor";
+        final HttpClient.Response response = HttpClient.create(new URL("https://httpbin.org/post"), "POST")
+                .setHeader("Content-Type", "text/plain")
+                .setRequestBody(text.getBytes(StandardCharsets.UTF_8))
+                .connect();
+        assertThat(response.getResponseCode(), is(200));
+        try (final InputStream in = response.getContent();
+             final JsonReader json = JsonProvider.provider().createReader(in)) {
+            assertThat(json.readObject().getString("data"), is(text));
+        }
+    }
+
+    @Test
+    public void testRelativeRedirects() throws Exception {
+        final HttpClient.Response response = HttpClient.create(new URL("https://httpbin.org/relative-redirect/5")).connect();
+        assertThat(response.getResponseCode(), is(200));
+        assertThat(response.getContentLength() > 100, is(true));
+    }
+
+    @Test
+    public void testAbsoluteRedirects() throws Exception {
+        final HttpClient.Response response = HttpClient.create(new URL("https://httpbin.org/absolute-redirect/5")).connect();
+        assertThat(response.getResponseCode(), is(200));
+        assertThat(response.getContentLength() > 100, is(true));
+    }
+
+    @Test(expected = IOException.class)
+    public void testTooMuchRedirects() throws Exception {
+        HttpClient.create(new URL("https://httpbin.org/redirect/5")).setMaxRedirects(4).connect();
+    }
+
+    @Test
+    public void test418() throws Exception {
+        // https://tools.ietf.org/html/rfc2324
+        final HttpClient.Response response = HttpClient.create(new URL("https://httpbin.org/status/418")).connect();
+        assertThat(response.getResponseCode(), is(418));
+        assertThat(response.getResponseMessage(), is("I'M A TEAPOT"));
+        final String content = response.fetchContent();
+        assertThat(content, containsString("-=[ teapot ]=-"));
+    }
+
+    @Test
+    public void testRequestInTime() throws Exception {
+        final HttpClient.Response response = HttpClient.create(new URL("https://httpbin.org/delay/3")).setReadTimeout(3500).connect();
+        assertThat(response.getResponseCode(), is(200));
+    }
+
+    @Test(expected = IOException.class)
+    public void testTakesTooLong() throws Exception {
+        HttpClient.create(new URL("https://httpbin.org/delay/3")).setReadTimeout(2500).connect();
+    }
+}