add HttpUtils for syncing policy

joylive-core/joylive-core-api/src/main/java/com/jd/live/agent/core/util/HttpUtils.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright © ${year} ${owner} (${email})
+ *
+ * Licensed 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 com.jd.live.agent.core.util;
+
+import java.io.*;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.Inflater;
+import java.util.zip.InflaterInputStream;
+
+/**
+ * Utility class for handling HTTP requests. Provides convenience methods to send HTTP GET requests
+ * and process the responses.
+ * <p>
+ * This class simplifies the connection setup and response handling by encapsulating the necessary
+ * steps to configure {@link HttpURLConnection}, execute the request, and process the incoming data.
+ * It deals with common setup configurations and response content encodings such as gzip and deflate.
+ * <p>
+ * Example usage:
+ * <pre>
+ *     String result = HttpUtils.get("http://example.com/api/data", connection -> {
+ *         // Custom connection configuration
+ *         connection.setConnectTimeout(10000);
+ *         connection.setReadTimeout(10000);
+ *     }, reader -> {
+ *         // Process the response with BufferedReader
+ *         return reader.lines().collect(Collectors.joining("\n"));
+ *     });
+ * </pre>
+ * <p>
+ * The class is designed to be flexible and allows for custom configuration and processing steps to be
+ * provided by the caller.
+ */
+public class HttpUtils {
+
+    /**
+     * Executes an HTTP GET request to the specified URI, allowing for custom configuration of the
+     * {@link HttpURLConnection} and processing of the response using a provided function.
+     *
+     * @param <T>       the type of the object returned by the processing function
+     * @param uri       the URI to send the GET request to
+     * @param configure a {@link Consumer} that accepts an {@link HttpURLConnection} to apply additional configuration
+     * @param function  a {@link Function} that takes a {@link Reader} and returns an object of type {@code T} after processing the response
+     * @return an object of type {@code T} as returned by the provided {@code function}
+     * @throws IOException if an I/O error occurs during the connection or if the HTTP response code is not {@link HttpURLConnection#HTTP_OK}
+     */
+    public static <T> T get(String uri, Consumer<HttpURLConnection> configure, Function<Reader, T> function) throws IOException {
+        URL url = new URL(uri);
+        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+        try {
+            connection.setRequestProperty("Connection", "keep-alive");
+            connection.setRequestProperty("Accept-Encoding", "gzip, deflate");
+            connection.setRequestProperty("Accept-Charset", "UTF-8");
+            connection.setRequestProperty("contentType", "UTF-8");
+            connection.setRequestMethod("GET");
+            connection.setDoOutput(false);
+            connection.setDoInput(true);
+            connection.setInstanceFollowRedirects(true);
+            configure.accept(connection);
+            connection.connect();
+            int responseCode = connection.getResponseCode();
+            if (responseCode == HttpURLConnection.HTTP_OK) {
+                InputStream is = connection.getInputStream();
+                String encoding = connection.getContentEncoding();
+                if (encoding != null && encoding.contains("gzip")) {
+                    is = new GZIPInputStream(is);
+                } else if (encoding != null && encoding.contains("deflate")) {
+                    is = new InflaterInputStream(is, new Inflater(true));
+                }
+                try (BufferedReader reader = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8))) {
+                    return function.apply(reader);
+                }
+            }
+            throw new IOException("Failed to get " + uri + ". http response code:" + responseCode);
+        } finally {
+            connection.disconnect();
+        }
+    }
+}