feat: Support retry in open api client

Author: zth9

CHANGES.md

@@ -8,6 +8,7 @@ Apollo Java 2.5.0
 
 * [Feature Provide a new open APl to return the organization list](https://github.com/apolloconfig/apollo-java/pull/102)
 * [Feature Added a new feature to get instance count by namespace.](https://github.com/apolloconfig/apollo-java/pull/103)
+* [Feature Support retry in open api client.](https://github.com/apolloconfig/apollo-java/pull/105)
 
 ------------------
 All issues and pull requests are [here](https://github.com/apolloconfig/apollo-java/milestone/5?closed=1)

apollo-openapi/src/main/java/com/ctrip/framework/apollo/openapi/client/ApolloOpenApiClient.java

@@ -17,6 +17,7 @@
 package com.ctrip.framework.apollo.openapi.client;
 
 import com.ctrip.framework.apollo.openapi.client.constant.ApolloOpenApiConstants;
+import com.ctrip.framework.apollo.openapi.client.extend.ApolloStandardHttpRequestRetryHandler;
 import com.ctrip.framework.apollo.openapi.client.service.AppOpenApiService;
 import com.ctrip.framework.apollo.openapi.client.service.ClusterOpenApiService;
 import com.ctrip.framework.apollo.openapi.client.service.ItemOpenApiService;
@@ -55,10 +56,11 @@ public class ApolloOpenApiClient {
   private final InstanceOpenApiService instanceService;
   private static final Gson GSON = new GsonBuilder().setDateFormat(ApolloOpenApiConstants.JSON_DATE_FORMAT).create();
 
-  private ApolloOpenApiClient(String portalUrl, String token, RequestConfig requestConfig) {
+  private ApolloOpenApiClient(String portalUrl, String token, RequestConfig requestConfig, int retryCount) {
     this.portalUrl = portalUrl;
     this.token = token;
     CloseableHttpClient client = HttpClients.custom().setDefaultRequestConfig(requestConfig)
+        .setRetryHandler(retryCount > 0 ? new ApolloStandardHttpRequestRetryHandler(retryCount) : null)
         .setDefaultHeaders(Lists.newArrayList(new BasicHeader("Authorization", token))).build();
 
     String baseUrl = this.portalUrl + ApolloOpenApiConstants.OPEN_API_V1_PREFIX;
@@ -273,6 +275,7 @@ public static class ApolloOpenApiClientBuilder {
     private String token;
     private int connectTimeout = -1;
     private int readTimeout = -1;
+    private int retryCount = -1;
 
     /**
      * @param portalUrl The apollo portal url, e.g http://localhost:8070
@@ -306,6 +309,11 @@ public ApolloOpenApiClientBuilder withReadTimeout(int readTimeout) {
       return this;
     }
 
+    public ApolloOpenApiClientBuilder withRetryCount(int retryCount) {
+      this.retryCount = retryCount;
+      return this;
+    }
+
     public ApolloOpenApiClient build() {
       Preconditions.checkArgument(!Strings.isNullOrEmpty(portalUrl), "Portal url should not be null or empty!");
       Preconditions.checkArgument(portalUrl.startsWith("http://") || portalUrl.startsWith("https://"), "Portal url should start with http:// or https://" );
@@ -322,7 +330,7 @@ public ApolloOpenApiClient build() {
       RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(connectTimeout)
           .setSocketTimeout(readTimeout).build();
 
-      return new ApolloOpenApiClient(portalUrl, token, requestConfig);
+      return new ApolloOpenApiClient(portalUrl, token, requestConfig, retryCount);
     }
   }
 }

apollo-openapi/src/main/java/com/ctrip/framework/apollo/openapi/client/extend/ApolloStandardHttpRequestRetryHandler.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2022 Apollo Authors
+ *
+ * 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.ctrip.framework.apollo.openapi.client.extend;
+
+import org.apache.http.HttpRequest;
+import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
+
+import javax.net.ssl.SSLException;
+import java.net.ConnectException;
+import java.net.NoRouteToHostException;
+import java.net.UnknownHostException;
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ *
+ * @author zth9
+ * @date 2025-05-07
+ */
+public class ApolloStandardHttpRequestRetryHandler extends DefaultHttpRequestRetryHandler {
+
+    private final Map<String, Boolean> idempotentMethods;
+
+    public ApolloStandardHttpRequestRetryHandler(int retryCount) {
+        super(retryCount, true, Arrays.asList(
+                UnknownHostException.class,
+                ConnectException.class,
+                NoRouteToHostException.class,
+                SSLException.class));
+        this.idempotentMethods = new ConcurrentHashMap<>();
+        this.idempotentMethods.put("GET", Boolean.TRUE);
+        this.idempotentMethods.put("HEAD", Boolean.TRUE);
+        this.idempotentMethods.put("PUT", Boolean.TRUE);
+        this.idempotentMethods.put("DELETE", Boolean.TRUE);
+        this.idempotentMethods.put("OPTIONS", Boolean.TRUE);
+        this.idempotentMethods.put("TRACE", Boolean.TRUE);
+    }
+
+    @Override
+    protected boolean handleAsIdempotent(final HttpRequest request) {
+        final String method = request.getRequestLine().getMethod().toUpperCase(Locale.ROOT);
+        final Boolean b = this.idempotentMethods.get(method);
+        return b != null && b.booleanValue();
+    }
+}

apollo-openapi/src/test/java/com/ctrip/framework/apollo/openapi/client/ApolloOpenApiClientIntegrationTest.java

@@ -63,6 +63,7 @@ ApolloOpenApiClient newClient() {
         .withToken(someToken)
         .withReadTimeout(2000 * 1000)
         .withConnectTimeout(2000 * 1000)
+        .withRetryCount(3)
         .build();
   }