Changs for Bug: https://github.com/apache/apisix-java-plugin-runner/i…

runner-core/src/main/java/org/apache/apisix/plugin/runner/handler/RpcCallHandler.java

@@ -17,39 +17,38 @@
 
 package org.apache.apisix.plugin.runner.handler;
 
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Queue;
-import java.util.Set;
-
 import com.google.common.cache.Cache;
 import io.github.api7.A6.Err.Code;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.SimpleChannelInboundHandler;
+import lombok.RequiredArgsConstructor;
 import org.apache.apisix.plugin.runner.A6Conf;
-import org.apache.apisix.plugin.runner.A6ErrRequest;
-import org.apache.apisix.plugin.runner.A6ErrResponse;
 import org.apache.apisix.plugin.runner.A6Request;
-import org.apache.apisix.plugin.runner.ExtraInfoRequest;
-import org.apache.apisix.plugin.runner.ExtraInfoResponse;
 import org.apache.apisix.plugin.runner.HttpRequest;
-import org.apache.apisix.plugin.runner.HttpResponse;
 import org.apache.apisix.plugin.runner.PostRequest;
+import org.apache.apisix.plugin.runner.HttpResponse;
 import org.apache.apisix.plugin.runner.PostResponse;
+import org.apache.apisix.plugin.runner.A6ErrRequest;
+import org.apache.apisix.plugin.runner.A6ErrResponse;
+import org.apache.apisix.plugin.runner.ExtraInfoResponse;
+import org.apache.apisix.plugin.runner.ExtraInfoRequest;
+import org.apache.apisix.plugin.runner.constants.Constants;
+import org.apache.apisix.plugin.runner.filter.PluginFilter;
+import org.apache.apisix.plugin.runner.filter.PluginFilterChain;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.util.CollectionUtils;
-import lombok.RequiredArgsConstructor;
 
-import org.apache.apisix.plugin.runner.constants.Constants;
-import org.apache.apisix.plugin.runner.filter.PluginFilter;
-import org.apache.apisix.plugin.runner.filter.PluginFilterChain;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
+import java.util.HashSet;
+import java.util.Collection;
+import java.util.Objects;
 
 @RequiredArgsConstructor
 public class RpcCallHandler extends SimpleChannelInboundHandler<A6Request> {
@@ -168,7 +167,7 @@ private void handleHttpRespCall(ChannelHandlerContext ctx, PostRequest request)
 
         // save HttpCallRequest
         postReq = request;
-        postResp = new PostResponse(postReq.getRequestId());
+        postResp = new PostResponse(postReq.getRequestId(), request.getUpstreamHeaders());
 
         confToken = postReq.getConfToken();
         A6Conf conf = cache.getIfPresent(confToken);

runner-core/src/test/java/org/apache/apisix/plugin/runner/handler/PostFilterTest.java

@@ -82,7 +82,7 @@ public void postFilter(PostRequest request, PostResponse response, PluginFilterC
                         System.out.println("do post filter: UpStreamFilter, order: " + chain.getIndex());
                         System.out.println("do post filter: UpStreamFilter, conf: " + request.getConfig(this));
                         System.out.println("do post filter: UpStreamFilter, upstreamStatusCode: " + request.getUpstreamStatusCode());
-                        for (Map.Entry<String, String> header : request.getUpstreamHeaders().entrySet()) {
+                        for (Map.Entry<String, List<String>> header : request.getUpstreamHeaders().entrySet()) {
                             System.out.println("do post filter: UpStreamFilter, upstreamHeader key: " + header.getKey());
                             System.out.println("do post filter: UpStreamFilter, upstreamHeader value: " + header.getValue());
                         }
@@ -150,6 +150,6 @@ void doPostFilter() {
         Assertions.assertTrue(bytes.toString().contains("do post filter: UpStreamFilter, conf: {\"conf_key1\":\"conf_value1\",\"conf_key2\":2}"));
         Assertions.assertTrue(bytes.toString().contains("do post filter: UpStreamFilter, upstreamStatusCode: 418"));
         Assertions.assertTrue(bytes.toString().contains("do post filter: UpStreamFilter, upstreamHeader key: headerKey"));
-        Assertions.assertTrue(bytes.toString().contains("do post filter: UpStreamFilter, upstreamHeader value: headerValue"));
+        Assertions.assertTrue(bytes.toString().contains("do post filter: UpStreamFilter, upstreamHeader value: [headerValue]"));
     }
 }

runner-plugin-sdk/src/main/java/org/apache/apisix/plugin/runner/PostRequest.java

@@ -25,8 +25,10 @@
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.ArrayList;
 
 public class PostRequest implements A6Request {
     private final Req req;
@@ -35,7 +37,7 @@ public class PostRequest implements A6Request {
 
     private Map<String, String> config;
 
-    private Map<String, String> headers;
+    private Map<String, List<String>> headers;
 
     private Integer status;
 
@@ -76,12 +78,13 @@ public String getConfig(PluginFilter filter) {
         return config.getOrDefault(filter.name(), null);
     }
 
-    public Map<String, String> getUpstreamHeaders() {
+    public Map<String, List<String>> getUpstreamHeaders() {
         if (Objects.isNull(headers)) {
             headers = new HashMap<>();
             for (int i = 0; i < req.headersLength(); i++) {
                 TextEntry header = req.headers(i);
-                headers.put(header.name(), header.value());
+                headers.putIfAbsent(header.name(), new ArrayList<>());
+                headers.get(header.name()).add(header.value());
             }
         }
         return headers;

runner-plugin-sdk/src/main/java/org/apache/apisix/plugin/runner/PostResponse.java

@@ -29,8 +29,10 @@
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.ArrayList;
 
 public class PostResponse implements A6Response {
 
@@ -42,12 +44,13 @@ public class PostResponse implements A6Response {
 
     private Integer statusCode;
 
-    private Map<String, String> headers;
+    private Map<String, List<String>> headers;
 
     private Charset charset;
 
-    public PostResponse(long requestId) {
+    public PostResponse(long requestId, Map<String, List<String>> headers) {
         this.requestId = requestId;
+        this.headers = headers != null ? new HashMap<>(headers) : new HashMap<>();
         this.charset = StandardCharsets.UTF_8;
     }
 
@@ -63,16 +66,27 @@ public ByteBuffer encode() {
 
         int headerIndex = -1;
         if (!CollectionUtils.isEmpty(headers)) {
-            int[] headerTexts = new int[headers.size()];
+            int hsize = 0;
+            for (String hkey: headers.keySet()) {
+                List<String> headerValues = headers.get(hkey);
+                hsize += CollectionUtils.isEmpty(headerValues) ? 0 : headerValues.size();
+            }
+
+            int[] headerTexts = new int[hsize];
             int i = -1;
-            for (Map.Entry<String, String> header : headers.entrySet()) {
+            for (Map.Entry<String, List<String>> header : headers.entrySet()) {
                 int key = builder.createString(header.getKey());
-                int value = 0;
-                if (!Objects.isNull(header.getValue())) {
-                    value = builder.createString(header.getValue());
+                List<String> headerValues = header.getValue();
+                if (!CollectionUtils.isEmpty(headerValues)) {
+                    for (String hv: headerValues) {
+                        int value = 0;
+                        if (!Objects.isNull(hv)) {
+                            value = builder.createString(hv);
+                        }
+                        int text = TextEntry.createTextEntry(builder, key, value);
+                        headerTexts[++i] = text;
+                    }
                 }
-                int text = TextEntry.createTextEntry(builder, key, value);
-                headerTexts[++i] = text;
             }
             headerIndex = Resp.createHeadersVector(builder, headerTexts);
         }
@@ -116,7 +130,27 @@ public void setHeader(String headerKey, String headerValue) {
         if (Objects.isNull(headers)) {
             headers = new HashMap<>();
         }
-        headers.put(headerKey, headerValue);
+
+        headers.put(headerKey, new ArrayList<>());
+        headers.get(headerKey).add(headerValue);
+    }
+
+    private void addHeader(String headerKey, String headerValue) {
+        if (headerKey == null) {
+            logger.warn("headerKey is null, ignore it");
+            return;
+        }
+
+        if (Objects.isNull(headers)) {
+            headers = new HashMap<>();
+        }
+
+        headers.putIfAbsent(headerKey, new ArrayList<>());
+        headers.get(headerKey).add(headerValue);
+    }
+
+    private Map<String, List<String>> headers() {
+        return headers;
     }
 
     public void setBody(String body) {

runner-plugin-sdk/src/test/java/org/apache/apisix/plugin/runner/PostResponseTest.java

@@ -23,9 +23,11 @@
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.ArrayList;
+import java.util.Map;
 
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -37,8 +39,9 @@ void testEncodeWithSetCharset() {
         long requestId = 1L;
         String body = "dummy body";
         Charset charset = StandardCharsets.UTF_16;
+        Map<String, List<String>> headers = new HashMap<>();
 
-        PostResponse postResponse = new PostResponse(requestId);
+        PostResponse postResponse = new PostResponse(requestId, headers);
         postResponse.setBody(body);
         postResponse.setCharset(charset);
 
@@ -53,8 +56,9 @@ void testEncodeWithoutSetCharset() {
         long requestId = 1L;
         String body = "dummy body";
         Charset charset = StandardCharsets.UTF_8;
+        Map<String, List<String>> headers = new HashMap<>();
 
-        PostResponse postResponse = new PostResponse(requestId);
+        PostResponse postResponse = new PostResponse(requestId, headers);
         postResponse.setBody(body);
 
         ByteBuffer encoded = postResponse.encode();

sample/src/main/java/org/apache/apisix/plugin/runner/filter/ResponseFilter.java

@@ -21,8 +21,10 @@
 import org.apache.apisix.plugin.runner.PostRequest;
 import org.apache.apisix.plugin.runner.PostResponse;
 import org.springframework.stereotype.Component;
+import org.springframework.util.CollectionUtils;
 
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 @Component
@@ -39,8 +41,8 @@ public void postFilter(PostRequest request, PostResponse response, PluginFilterC
         Map<String, Object> conf = new HashMap<>();
         conf = gson.fromJson(configStr, conf.getClass());
 
-        Map<String, String> headers = request.getUpstreamHeaders();
-        String contentType = headers.get("Content-Type");
+        Map<String, List<String>> headers = request.getUpstreamHeaders();
+        String contentType = CollectionUtils.isEmpty(headers.get("Content-Type")) ? null : headers.get("Content-Type").get(0);
         Integer upstreamStatusCode = request.getUpstreamStatusCode();
 
         response.setStatusCode(Double.valueOf(conf.get("response_code").toString()).intValue());