fix: replace '+' to '%2B' to handle page strs encode (apache#1437)

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/page/PageState.java

@@ -29,6 +29,8 @@ public class PageState {
 
     public static final byte[] EMPTY_BYTES = new byte[0];
     public static final PageState EMPTY = new PageState(EMPTY_BYTES, 0, 0);
+    public static final char SPACE = ' ';
+    public static final char PLUS = '+';
 
     private final byte[] position;
     private final int offset;
@@ -73,6 +75,12 @@ private byte[] toBytes() {
 
     public static PageState fromString(String page) {
         E.checkNotNull(page, "page");
+        /*
+         * URLDecoder will auto decode '+' to space in url due to the request
+         * of HTML4, so we choose to replace the space to '+' after getting it
+         * More details refer to #1437
+         */
+        page = page.replace(SPACE, PLUS);
         return fromBytes(toBytes(page));
     }
 

hugegraph-test/src/main/java/com/baidu/hugegraph/core/VertexCoreTest.java

@@ -21,6 +21,7 @@
 
 import java.math.BigDecimal;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashSet;
@@ -54,6 +55,7 @@
 import com.baidu.hugegraph.backend.id.SnowflakeIdGenerator;
 import com.baidu.hugegraph.backend.id.SplicingIdGenerator;
 import com.baidu.hugegraph.backend.page.PageInfo;
+import com.baidu.hugegraph.backend.page.PageState;
 import com.baidu.hugegraph.backend.query.Condition;
 import com.baidu.hugegraph.backend.query.ConditionQuery;
 import com.baidu.hugegraph.backend.query.Query;
@@ -6667,6 +6669,35 @@ public void testQueryByPageWithInvalidPage() {
         });
     }
 
+    @Test
+    public void testQueryByPageWithSpecialBase64Chars() {
+        Assume.assumeTrue("Not support paging",
+                          storeFeatures().supportsQueryByPage());
+        final String pageWith3Base64Chars = "AAAAADsyABwAEAqI546LS6WW57unBgA" +
+                                            "EAAAAAPB////+8H////4alhxAZS8va6" +
+                                            "opcAKpklipAAQAAAAAAAAAAQ==";
+
+        final String pageWithSpace = "AAAAADsyABwAEAqI546LS6WW57unBgAEAAAAAP" +
+                                     "B//// 8H////4alhxAZS8va6opcAKpklipAAQA" +
+                                     "AAAAAAAAAQ==";
+
+        HugeGraph graph = graph();
+        init100Books();
+
+        // Contains valid character '+' and '/' and '='
+        GraphTraversal<Vertex, Vertex> traversal;
+        traversal = graph.traversal().V()
+                         .has("~page", pageWith3Base64Chars).limit(10);
+        Assert.assertNotNull(traversal);
+        CloseableIterator.closeIterator(traversal);
+
+        // Contains invalid base64 character ' ', will be replaced to '+'
+        traversal = graph.traversal().V()
+                         .has("~page", pageWithSpace).limit(10);
+        Assert.assertNotNull(traversal);
+        CloseableIterator.closeIterator(traversal);
+    }
+
     @Test
     public void testQueryByPageWithInvalidLimit() {
         Assume.assumeTrue("Not support paging",

hugegraph-test/src/main/java/com/baidu/hugegraph/unit/UnitTestSuite.java

@@ -37,6 +37,7 @@
 import com.baidu.hugegraph.unit.core.DirectionsTest;
 import com.baidu.hugegraph.unit.core.ExceptionTest;
 import com.baidu.hugegraph.unit.core.LocksTableTest;
+import com.baidu.hugegraph.unit.core.PageStateTest;
 import com.baidu.hugegraph.unit.core.QueryTest;
 import com.baidu.hugegraph.unit.core.RangeTest;
 import com.baidu.hugegraph.unit.core.RolePermissionTest;
@@ -101,6 +102,7 @@
     ExceptionTest.class,
     BackendStoreSystemInfoTest.class,
     TraversalUtilTest.class,
+    PageStateTest.class,
 
     /* serializer */
     BytesBufferTest.class,

hugegraph-test/src/main/java/com/baidu/hugegraph/unit/core/PageStateTest.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2017 HugeGraph Authors
+ *
+ * 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.
+ */
+
+package com.baidu.hugegraph.unit.core;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+
+import com.baidu.hugegraph.backend.BackendException;
+import com.baidu.hugegraph.backend.page.PageState;
+import com.baidu.hugegraph.testutil.Assert;
+
+public class PageStateTest {
+
+    private String pageWith3Base64Chars = "AAAAADsyABwAEAqI546LS6WW57unBgA" +
+                                          "EAAAAAPB////+8H////4alhxAZS8va6" +
+                                          "opcAKpklipAAQAAAAAAAAAAQ==";
+
+    private String pageWithSpace = "AAAAADsyABwAEAqI546LS6WW57unBgAEAAAAAP" +
+                                   "B//// 8H////4alhxAZS8va6opcAKpklipAAQA" +
+                                   "AAAAAAAAAQ==";
+
+    @Test
+    public void testOriginalStringPageToBytes() {
+        byte[] validPage = PageState.toBytes(pageWith3Base64Chars);
+        Assert.assertNotNull(validPage);
+
+        Assert.assertThrows(BackendException.class, () -> {
+            PageState.toBytes(pageWithSpace);
+        }, e -> {
+            Assert.assertContains("Invalid page:", e.toString());
+        });
+    }
+
+    @Test
+    public void testDecodePageWithSpecialBase64Chars() {
+        // Assert decode '+' and '/' and '=' and space successfully
+        Assert.assertNotNull(PageState.fromString(pageWith3Base64Chars));
+
+        byte[] decodePlus = PageState.fromString(pageWith3Base64Chars)
+                                     .position();
+        byte[] decodeSpace = PageState.fromString(pageWithSpace).position();
+
+        Assert.assertTrue(Arrays.equals(decodePlus, decodeSpace));
+    }
+
+    @Test
+    public void testDecodePageWithInvalidStringPage() {
+        final String invalidPageWithBase64Chars = "dGVzdCBiYXNlNjQ=";
+
+        Assert.assertThrows(BackendException.class, () -> {
+            PageState.fromString(invalidPageWithBase64Chars);
+        }, e -> {
+            Assert.assertContains("Invalid page: '0x", e.toString());
+        });
+
+        final String invalidBase64Chars = "!abc~";
+        Assert.assertThrows(BackendException.class, () -> {
+            PageState.fromString(invalidBase64Chars);
+        }, e -> {
+            Assert.assertContains("Invalid page:", e.toString());
+        });
+    }
+
+    @Test
+    public void testEmptyPageState() {
+        Assert.assertEquals(0, PageState.EMPTY.offset());
+        Assert.assertNull(PageState.EMPTY.toString());
+
+        Assert.assertEquals(PageState.EMPTY,
+                            PageState.fromBytes(PageState.EMPTY_BYTES));
+    }
+}