Fix NullPointerException bug (#3176)

sharding-core/sharding-core-common/src/main/java/org/apache/shardingsphere/core/rule/EncryptRule.java

@@ -231,8 +231,12 @@ public final class EncryptRule implements BaseRule {
             
             @Override
             public Object apply(final Object input) {
+                if (input == null) {
+                    return null;
+                } else {
                     return ((ShardingQueryAssistedEncryptor) shardingEncryptor.get()).queryAssistedEncrypt(input.toString());
                 }
+            }
         });
     }
     
@@ -251,8 +255,12 @@ public final class EncryptRule implements BaseRule {
             
             @Override
             public Object apply(final Object input) {
+                if (input == null) {
+                    return null;
+                } else {
                     return String.valueOf(shardingEncryptor.get().encrypt(input.toString()));
                 }
+            }
         });
     }
     

sharding-core/sharding-core-common/src/test/java/org/apache/shardingsphere/core/rule/EncryptRuleTest.java

+/*
+ * 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 org.apache.shardingsphere.core.rule;
+
+import org.apache.shardingsphere.api.config.encrypt.EncryptColumnRuleConfiguration;
+import org.apache.shardingsphere.api.config.encrypt.EncryptRuleConfiguration;
+import org.apache.shardingsphere.api.config.encrypt.EncryptTableRuleConfiguration;
+import org.apache.shardingsphere.api.config.encrypt.EncryptorRuleConfiguration;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Properties;
+
+import static org.junit.Assert.assertNull;
+
+/**
+ * @author kezhenxu94
+ */
+public class EncryptRuleTest {
+    private final String table = "table";
+    private final String column = "column";
+
+    private EncryptRuleConfiguration encryptRuleConfig;
+
+    @Before
+    public void before() {
+        Properties props = new Properties();
+
+        EncryptorRuleConfiguration encryptorConfig = new EncryptorRuleConfiguration("assistedTest", props);
+        EncryptColumnRuleConfiguration columnConfig = new EncryptColumnRuleConfiguration("plain_pwd", "cipher_pwd", "", "aes");
+        EncryptTableRuleConfiguration tableConfig = new EncryptTableRuleConfiguration(Collections.singletonMap(column, columnConfig));
+
+        encryptRuleConfig = new EncryptRuleConfiguration();
+        encryptRuleConfig.getEncryptors().put("aes", encryptorConfig);
+        encryptRuleConfig.getTables().put(table, tableConfig);
+    }
+
+    @Test
+    public void testGetEncryptAssistedQueryValues() {
+        List<Object> encryptAssistedQueryValues = new EncryptRule(encryptRuleConfig).getEncryptAssistedQueryValues(table, column, Collections.singletonList(null));
+
+        for (final Object value : encryptAssistedQueryValues) {
+            assertNull(value);
+        }
+    }
+
+    @Test
+    public void testGetEncryptValues() {
+        List<Object> encryptAssistedQueryValues = new EncryptRule(encryptRuleConfig).getEncryptValues(table, column, Collections.singletonList(null));
+
+        for (final Object value : encryptAssistedQueryValues) {
+            assertNull(value);
+        }
+    }
+}
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