[#noissue] Refactor PathRewriter

web/src/main/java/com/navercorp/pinpoint/web/servlet/DefaultVersionToken.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2023 NAVER Corp.
+ *
+ * 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.navercorp.pinpoint.web.servlet;
+
+public class DefaultVersionToken implements VersionToken {
+    private static final String prefix = "v";
+
+    @Override
+    public boolean isVersion(String token) {
+        if (!token.startsWith(prefix)) {
+            return false;
+        }
+        for (int i = prefix.length(); i < token.length(); i++) {
+            final char c = token.charAt(i);
+            if (!Character.isDigit(c)) {
+                return false;
+            }
+
+        }
+        return true;
+    }
+
+}

web/src/main/java/com/navercorp/pinpoint/web/servlet/HttpIntentRoutingFilter.java

@@ -19,41 +19,27 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
-import javax.servlet.Filter;
 import javax.servlet.FilterChain;
 import javax.servlet.FilterConfig;
 import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpFilter;
 import javax.servlet.http.HttpServletRequest;
 import java.io.IOException;
-import java.util.List;
-import java.util.Objects;
 
 /**
  * @author youngjin.kim2
  */
-public class HttpIntentRoutingFilter implements Filter {
-
-    private static final FrontApplicationRegistration DEFAULT_FRONT_REGISTRATION = FrontApplicationRegistration.of("/");
-
-    private static final List<String> RESOURCE_BASE_PATHS = List.of(
-            "assets",
-            "fonts",
-            "img"
-    );
+public class HttpIntentRoutingFilter extends HttpFilter {
 
     private final Logger logger = LogManager.getLogger(this.getClass());
 
-    private final List<FrontApplicationRegistration> registrations;
+    private final VersionPrefixRewriter rewriter = new VersionPrefixRewriter();
 
-    public HttpIntentRoutingFilter(List<FrontApplicationRegistration> registrations) {
-        this.registrations = Objects.requireNonNullElse(registrations, List.of(DEFAULT_FRONT_REGISTRATION));
-    }
 
     public HttpIntentRoutingFilter() {
-        this(List.of(DEFAULT_FRONT_REGISTRATION));
     }
 
     @Override
@@ -86,79 +72,14 @@ private void route(
     ) throws ServletException, IOException {
         String uri = request.getRequestURI();
 
-        if (uri.startsWith("/api/")) {
+        final String rewriteUrl = rewriter.rewrite(uri);
+        if (rewriteUrl == null) {
             chain.doFilter(request, response);
             return;
         }
-
-        for (FrontApplicationRegistration registration: this.registrations) {
-            if (uri.startsWith(registration.getBasePath())) {
-                routeToFrontApplication(request, response, chain, registration);
-                return;
-            }
-        }
-
-        chain.doFilter(request, response);
-    }
-
-    private void routeToFrontApplication(
-            HttpServletRequest request,
-            ServletResponse response,
-            FilterChain chain,
-            FrontApplicationRegistration frontRegistration
-    ) throws ServletException, IOException {
-        String basePath = frontRegistration.getBasePath();
-        String path = trimFirstSlash(request.getRequestURI().substring(basePath.length()));
-        String firstToken = path.split("/", 2)[0];
-        if (isStaticResource(firstToken)) {
-            chain.doFilter(request, response);
-        } else {
-            String entryHtml = basePath + "/index.html";
-            forwardTo(request, response, entryHtml);
-            logger.debug("requestUri: {} --(forward)--> {}", request.getRequestURI(), entryHtml);
-        }
-    }
-
-    private static void forwardTo(
-            HttpServletRequest request,
-            ServletResponse response,
-            String entryHtml
-    ) throws ServletException, IOException {
-        RequestDispatcher dispatcher = request.getRequestDispatcher(entryHtml);
+        logger.debug("requestUri: {} --(forward)--> {}", uri, rewriteUrl);
+        RequestDispatcher dispatcher = request.getRequestDispatcher(rewriteUrl);
         dispatcher.forward(request, response);
     }
 
-    private static boolean isStaticResource(String firstToken) {
-        for (String resourceBasePath : RESOURCE_BASE_PATHS) {
-            if (firstToken.equals(resourceBasePath)) {
-                return true;
-            }
-        }
-        return firstToken.indexOf('.') != -1;
-    }
-
-    private static String trimFirstSlash(String s) {
-        if (s.length() > 0 && s.charAt(0) == '/') {
-            return s.substring(1);
-        }
-        return s;
-    }
-
-    public static class FrontApplicationRegistration {
-
-        private final String basePath;
-
-        public FrontApplicationRegistration(String basePath) {
-            this.basePath = Objects.requireNonNull(basePath, "basePath");
-        }
-
-        public static FrontApplicationRegistration of(String basePath) {
-            return new FrontApplicationRegistration(basePath);
-        }
-
-        public String getBasePath() {
-            return basePath;
-        }
-    }
-
 }

web/src/main/java/com/navercorp/pinpoint/web/servlet/VersionPrefixRewriter.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 2023 NAVER Corp.
+ *
+ * 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.navercorp.pinpoint.web.servlet;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.StringTokenizer;
+
+public class VersionPrefixRewriter {
+
+    static final String[] SPECIAL_PATHS = {
+            "api"
+    };
+
+    static final String[] RESOURCE_PATHS = {
+            "assets",
+            "fonts",
+            "img"
+    };
+
+    static final String MAIN = "/index.html";
+
+    private final VersionToken versionToken = new DefaultVersionToken();
+    private final String page;
+
+    private final List<String> specialPaths;
+    private final List<String> resourcePaths;
+
+
+    public VersionPrefixRewriter() {
+        this(MAIN, List.of(SPECIAL_PATHS), List.of(RESOURCE_PATHS));
+    }
+
+    public VersionPrefixRewriter(String page, List<String> specialPaths, List<String> resourcePaths) {
+        this.page = Objects.requireNonNull(page, "page");
+        this.specialPaths = Objects.requireNonNull(specialPaths, "specialPaths");
+        this.resourcePaths = Objects.requireNonNull(resourcePaths, "resourcePaths");
+    }
+
+    public String rewrite(String uri) {
+
+        final StringTokenizer tokenizer = new StringTokenizer(uri, "/");
+        if (!tokenizer.hasMoreTokens()) {
+            return page;
+        }
+
+        String command = tokenizer.nextToken();
+        if (specialPaths.contains(command)) {
+            return null;
+        }
+        // next token
+        String version = null;
+        if (versionToken.isVersion(command)) {
+            version = command;
+            command = nextToken(tokenizer);
+        }
+        if (command != null) {
+            // static resource
+            if (isStaticResource(command)) {
+                return null;
+            }
+        }
+
+        if (version == null) {
+            return page;
+        } else {
+            return '/' + version + page;
+        }
+    }
+
+    private String nextToken(StringTokenizer tokenizer) {
+        if (tokenizer.hasMoreTokens()) {
+            return tokenizer.nextToken();
+        }
+        return null;
+    }
+
+    private boolean isStaticResource(String command) {
+        if (resourcePaths.contains(command)) {
+            return true;
+        }
+        return command.indexOf('.') != -1;
+    }
+
+}

web/src/main/java/com/navercorp/pinpoint/web/servlet/VersionToken.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 NAVER Corp.
+ *
+ * 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.navercorp.pinpoint.web.servlet;
+
+public interface VersionToken {
+    boolean isVersion(String token);
+}

web/src/main/resources/applicationContext-web.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
-       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:util="http://www.springframework.org/schema/util"
-       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/util https://www.springframework.org/schema/util/spring-util.xsd">
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
 
     <bean id="commandHeaderTBaseSerializerFactory" class="com.navercorp.pinpoint.thrift.io.CommandHeaderTBaseSerializerFactory" factory-method="getDefaultInstance">
     </bean>
@@ -52,18 +52,7 @@
         <constructor-arg ref="metadataRowKeyDistributor2"/>
     </bean>
 
-    <util:list id="frontApplicationRegistrations">
-        <bean class="com.navercorp.pinpoint.web.servlet.HttpIntentRoutingFilter$FrontApplicationRegistration">
-            <constructor-arg name="basePath" value="/v3" />
-        </bean>
-        <bean class="com.navercorp.pinpoint.web.servlet.HttpIntentRoutingFilter$FrontApplicationRegistration">
-            <constructor-arg name="basePath" value="/" />
-        </bean>
-    </util:list>
-
-    <bean id="rewriteFilter" class="com.navercorp.pinpoint.web.servlet.HttpIntentRoutingFilter">
-        <constructor-arg name="registrations" ref="frontApplicationRegistrations" />
-    </bean>
+    <bean id="rewriteFilter" class="com.navercorp.pinpoint.web.servlet.HttpIntentRoutingFilter"/>
 
     <bean id="additionalServletRegistrationBeanFactory" class="com.navercorp.pinpoint.web.servlet.AdditionalServletRegistrationBeanFactory" />
     <bean id="apiServletRegistrationBean" factory-bean="additionalServletRegistrationBeanFactory" factory-method="addRegistration">