added LaxRedirectStrategy from 4.x

httpclient5/src/main/java/org/apache/hc/client5/http/impl/LaxRedirectStrategy.java

@@ -0,0 +1,95 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+package org.apache.hc.client5.http.impl;
+
+import org.apache.hc.client5.http.classic.methods.HttpDelete;
+import org.apache.hc.client5.http.classic.methods.HttpGet;
+import org.apache.hc.client5.http.classic.methods.HttpHead;
+import org.apache.hc.client5.http.classic.methods.HttpPost;
+import org.apache.hc.client5.http.protocol.RedirectStrategy;
+import org.apache.hc.core5.annotation.Contract;
+import org.apache.hc.core5.annotation.ThreadingBehavior;
+import org.apache.hc.core5.http.Header;
+import org.apache.hc.core5.http.HttpHeaders;
+import org.apache.hc.core5.http.HttpRequest;
+import org.apache.hc.core5.http.HttpResponse;
+import org.apache.hc.core5.http.HttpStatus;
+import org.apache.hc.core5.http.protocol.HttpContext;
+
+/**
+ * A lax implementation of the {@link RedirectStrategy} that automatically handles HTTP redirects
+ * for HEAD, GET, POST, and DELETE requests based on the response status code.
+ *
+ * <p>This strategy relaxes the HTTP specification restrictions on automatic redirection of POST
+ * requests, allowing redirects for these methods where the specification might otherwise prohibit
+ * them. This can be useful in scenarios where a server indicates a redirect for a POST request
+ * that the client should follow.</p>
+ *
+ * <p>This class is thread-safe and stateless, suitable for use across multiple threads
+ * without additional synchronization.</p>
+ *
+ * @since 5.4
+ */
+@Contract(threading = ThreadingBehavior.STATELESS)
+public class LaxRedirectStrategy extends DefaultRedirectStrategy {
+
+    public static final LaxRedirectStrategy INSTANCE = new LaxRedirectStrategy();
+
+    private static final String[] REDIRECT_METHODS = new String[]{HttpGet.METHOD_NAME, HttpPost.METHOD_NAME, HttpHead.METHOD_NAME, HttpDelete.METHOD_NAME};
+
+    @Override
+    public boolean isRedirected(final HttpRequest request, final HttpResponse response, final HttpContext context) {
+        if (!response.containsHeader(HttpHeaders.LOCATION)) {
+            return false;
+        }
+
+        final int statusCode = response.getCode();
+        final String method = request.getMethod();
+        final Header locationHeader = response.getFirstHeader("location");
+        switch (statusCode) {
+            case HttpStatus.SC_MOVED_TEMPORARILY:
+                return isRedirectable(method) && locationHeader != null;
+            case HttpStatus.SC_MOVED_PERMANENTLY:
+            case HttpStatus.SC_TEMPORARY_REDIRECT:
+                return isRedirectable(method);
+            case HttpStatus.SC_SEE_OTHER:
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    protected boolean isRedirectable(final String method) {
+        for (final String m : REDIRECT_METHODS) {
+            if (m.equalsIgnoreCase(method)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

httpclient5/src/test/java/org/apache/hc/client5/http/impl/TestLaxRedirectStrategy.java

@@ -0,0 +1,84 @@
+/*
+ * ====================================================================
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+package org.apache.hc.client5.http.impl;
+
+import org.apache.hc.client5.http.classic.methods.HttpDelete;
+import org.apache.hc.client5.http.classic.methods.HttpGet;
+import org.apache.hc.client5.http.classic.methods.HttpHead;
+import org.apache.hc.client5.http.classic.methods.HttpPost;
+import org.apache.hc.client5.http.classic.methods.HttpPut;
+import org.apache.hc.core5.http.HttpRequest;
+import org.apache.hc.core5.http.HttpResponse;
+import org.apache.hc.core5.http.HttpStatus;
+import org.apache.hc.core5.http.protocol.HttpContext;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+class TestLaxRedirectStrategy {
+    @Test
+    void testIsRedirectedWithHttpGet() {
+        testIsRedirected(new HttpGet("/get"), true);
+    }
+
+    @Test
+    void testIsRedirectedWithHttpPost() {
+        testIsRedirected(new HttpPost("/post"), true);
+    }
+
+    @Test
+    void testIsRedirectedWithHttpHead() {
+        testIsRedirected(new HttpHead("/head"), true);
+    }
+
+    @Test
+    void testIsRedirectedWithHttpDelete() {
+        testIsRedirected(new HttpDelete("/delete"), true);
+    }
+
+    @Test
+    void testIsRedirectedWithNonRedirectMethod() {
+        testIsRedirected(new HttpPut("/put"), false);
+    }
+
+    private void testIsRedirected(final HttpRequest request, final boolean expected) {
+        final LaxRedirectStrategy strategy = new LaxRedirectStrategy();
+        final HttpResponse response = mock(HttpResponse.class);
+        final HttpContext context = mock(HttpContext.class);
+
+        // Mock the response to simulate a redirect with a Location header
+        when(response.getCode()).thenReturn(HttpStatus.SC_MOVED_TEMPORARILY);
+        when(response.containsHeader("Location")).thenReturn(true);
+        when(response.getFirstHeader("location")).thenReturn(mock(org.apache.hc.core5.http.Header.class));
+        when(response.getFirstHeader("location").getValue()).thenReturn("http://localhost/redirect");
+
+        assertEquals(expected, strategy.isRedirected(request, response, context));
+    }
+}