Read plain or chunked body + tests

src/main/java/com/amihaiemil/docker/SocketResponse.java

@@ -39,8 +39,6 @@
  * @author Mihai Andronache (amihaiemil@gmail.com)
  * @version $Id$
  * @since 0.0.1
- * @todo #14:30min Refine the body reading logic. Have to take into account
- *  the Transfer-Encoding header and cover the empty body case.
  */
 final class SocketResponse implements Response {
 
@@ -114,14 +112,41 @@ public Map<String, List<String>> headers() {
 
     @Override
     public String body() {
-        return this.response.substring(this.response.indexOf("\n\n")).trim();
+        final Map<String, List<String>> headers = this.headers();
+        final String body;
+        if(headers.get("Content-Length") != null) {
+            final int length = Integer.valueOf(
+                headers.get("Content-Length").get(0)
+            );
+            body = this.response.substring(
+                this.response.indexOf("\n\n")
+            ).trim().substring(0, length);
+        } else {
+            if(headers.get("Transfer-Encoding") == null) {
+                throw new IllegalStateException(
+                    "Transfer-Encoding header is missing from the response."
+                );
+            } else {
+                final String enc = headers.get("Transfer-Encoding").get(0);
+                if("chunked".equalsIgnoreCase(enc)) {
+                    body = new ChunkedContent(
+                        this.response.substring(
+                            this.response.indexOf("\n\n")
+                        ).trim()
+                    ).toString();
+                } else {
+                    throw new IllegalStateException(
+                        "Only chunked encoding is supported for now."
+                    );
+                }
+            }
+        }
+        return body;
     }
 
     @Override
     public byte[] binary() {
-        return this.response.substring(
-            this.response.indexOf("\n\n")
-        ).getBytes();
+        return this.body().getBytes();
     }
 
     @Override
@@ -135,4 +160,42 @@ public <T extends Response> T as(final Class<T> type) {
             throw new IllegalStateException(ex);
         }
     }
+
+    /**
+     * Chunked content from an HTTP response.
+     */
+    final class ChunkedContent {
+
+        /**
+         * Content.
+         */
+        final String content;
+
+        /**
+         * Ctor.
+         * @param content Chunked content.
+         */
+        ChunkedContent(final String content) {
+            this.content = content;
+        }
+
+        /**
+         * Iterate over the lines of the chunked response and concatenate
+         * the chunks. Skip the first and next every second line since they
+         * contain the chunk's size. Ignore the last line since it's supposed
+         * to be 0. This is according to the "Transfer-Encoding: chunked" spec.
+         * @return The response's concatenated chunks, separated by whitespace.
+         */
+        @Override
+        public String toString() {
+            String concat = "";
+            final List<String> chunks = Arrays.asList(
+                this.content.split("\n")
+            );
+            for(int idx = 1; idx < chunks.size() - 1; idx += 2) {
+                concat += chunks.get(idx) + " ";
+            }
+            return concat.trim();
+        }
+    }
 }

src/test/java/com/amihaiemil/docker/SocketResponseTestCase.java

@@ -28,8 +28,9 @@
 import com.jcabi.http.Response;
 import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
+import org.junit.Assert;
 import org.junit.Test;
-
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 
@@ -110,12 +111,12 @@ public void headersWithNoContent() {
     @Test
     public void headersWithontent() {
         final String responseString = "HTTP/1.1 200 OK\n"
-                + "Api-Version: 1.35\n"
-                + "Content-Type: application/json\n"
-                + "Docker-Experimental: false\n"
-                + "Connection: close\n"
-                + "Content-Length: 2\n\n"
-                + "OK";
+            + "Api-Version: 1.35\n"
+            + "Content-Type: application/json\n"
+            + "Docker-Experimental: false\n"
+            + "Connection: close\n"
+            + "Content-Length: 2\n\n"
+            + "OK";
         final Response resp = new SocketResponse(null, responseString);
         final Map<String, List<String>> headers = resp.headers();
         MatcherAssert.assertThat(headers.size(), Matchers.is(5));
@@ -154,4 +155,150 @@ public void noHeaders() {
         final Map<String, List<String>> headers = resp.headers();
         MatcherAssert.assertThat(headers.isEmpty(), Matchers.is(Boolean.TRUE));
     }
+
+    /**
+     * A SocketResponse returns its chunked body.
+     */
+    @Test
+    public void chunkedBody() {
+        final String responseString = "HTTP/1.1 200 OK \n"
+            + "Content-Type: text/plain \n"
+            + "Transfer-Encoding: chunked\n"
+            + "\n"
+            + "7\n"
+            + "Mozilla\n"
+            + "9\n"
+            + "Developer\n"
+            + "7\n"
+            + "Network\n"
+            + "0\n"
+            + "\n";
+        final Response resp = new SocketResponse(null, responseString);
+        MatcherAssert.assertThat(
+            resp.body(),
+            Matchers.equalTo("Mozilla Developer Network")
+        );
+    }
+
+    /**
+     * A SocketResponse returns its plain body.
+     */
+    @Test
+    public void plainBody() {
+        final String responseString = "HTTP/1.1 200 OK \n"
+            + "Content-Type: text/plain \n"
+            + "Content-Length: 25\n"
+            + "\n"
+            + "Mozilla Developer Network\n\n";
+        final Response resp = new SocketResponse(null, responseString);
+        MatcherAssert.assertThat(
+            resp.body(),
+            Matchers.equalTo("Mozilla Developer Network")
+        );
+    }
+
+    /**
+     * A SocketResponse returns its plain body's bytes.
+     */
+    @Test
+    public void plainBodyBytes() {
+        final byte[] bytes = "Mozilla Developer Network".getBytes();
+        final String responseString = "HTTP/1.1 200 OK \n"
+            + "Content-Type: text/plain \n"
+            + "Content-Length: 25\n"
+            + "\n"
+            + "Mozilla Developer Network\n\n";
+        final Response resp = new SocketResponse(null, responseString);
+        MatcherAssert.assertThat(
+            Arrays.equals(bytes, resp.binary()),
+            Matchers.is(true)
+        );
+    }
+    /**
+     * A SocketResponse returns its chunked body's bytes.
+     */
+    @Test
+    public void chunkedBodyBytes() {
+        final byte[] bytes = "Mozilla Developer Network".getBytes();
+        final String responseString = "HTTP/1.1 200 OK \n"
+            + "Content-Type: text/plain \n"
+            + "Transfer-Encoding: chunked\n"
+            + "\n"
+            + "7\n"
+            + "Mozilla\n"
+            + "9\n"
+            + "Developer\n"
+            + "7\n"
+            + "Network\n"
+            + "0\n"
+            + "\n";
+        final Response resp = new SocketResponse(null, responseString);
+        MatcherAssert.assertThat(
+            Arrays.equals(bytes, resp.binary()),
+            Matchers.is(true)
+        );
+    }
+
+    /**
+     * A SocketResponse supports only chunked encoding for now.
+     */
+    @Test
+    public void onlyChunkedEncodingSupported() {
+        final byte[] bytes = "Mozilla Developer Network".getBytes();
+        final String responseString = "HTTP/1.1 200 OK \n"
+            + "Content-Type: text/plain \n"
+            + "Transfer-Encoding: gzip\n"
+            + "\n"
+            + "something in gzip";
+        final Response resp = new SocketResponse(null, responseString);
+        try {
+            resp.body();
+            Assert.fail("IllegalStateException should have been thrown.");
+        } catch (final IllegalStateException ise) {
+            MatcherAssert.assertThat(
+                ise.getMessage(),
+                Matchers.equalTo("Only chunked encoding is supported for now.")
+            );
+        }
+    }
+
+    /**
+     * When reading the response's body, the header Content-Length
+     * or Transfer-Encoding have to be present.
+     */
+    @Test
+    public void contentLengthAndEncodingHeadersMissing() {
+        final String responseString = "HTTP/1.1 200 OK \n"
+                + "Content-Type: text/plain \n"
+                + "\n"
+                + "both headers missing";
+        final Response resp = new SocketResponse(null, responseString);
+        try {
+            resp.body();
+            Assert.fail("IllegalStateException should have been thrown.");
+        } catch (final IllegalStateException ise) {
+            MatcherAssert.assertThat(
+                ise.getMessage(),
+                Matchers.equalTo(
+                    "Transfer-Encoding header is missing from the response."
+                )
+            );
+        }
+    }
+
+    /**
+     * SocketResponse can return an empty body.
+     */
+    @Test
+    public void emptyBody() {
+        final String responseString = "HTTP/1.1 200 OK\n"
+            + "Api-Version: 1.35\n"
+            + "Content-Type: application/json\n"
+            + "Docker-Experimental: false\n"
+            + "Connection: close\n"
+            + "Content-Length: 0\n\n";
+        final Response resp = new SocketResponse(null, responseString);
+        MatcherAssert.assertThat(resp.body(), Matchers.isEmptyString());
+    }
+
 }