Add the example of Selector in Nacos 2.0.4

nacos-cmdb-plugin-example/pom.xml

@@ -24,7 +24,6 @@
         <dependency>
             <groupId>com.alibaba.nacos</groupId>
             <artifactId>nacos-api</artifactId>
-            <version>0.7.0</version>
         </dependency>
         <dependency>
             <groupId>junit</groupId>

nacos-selector-plugin-exmaple/pom.xml

@@ -0,0 +1,89 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ pom.xml
+  ~ Copyright 2021 Qunhe Tech, all rights reserved.
+  ~ Qunhe PROPRIETARY/CONFIDENTIAL, any form of usage is subject to approval.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>nacos-examples</artifactId>
+        <groupId>com.alibaba.nacos</groupId>
+        <version>0.2.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>nacos-selector-plugin-exmaple</artifactId>
+
+    <name>nacos-selector-plugin-example</name>
+    <url>http://nacos.io</url>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.alibaba.nacos</groupId>
+            <artifactId>nacos-api</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.11</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <configuration>
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                </configuration>
+            </plugin>
+        </plugins>
+        <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
+            <plugins>
+                <plugin>
+                    <artifactId>maven-clean-plugin</artifactId>
+                    <version>3.0.0</version>
+                </plugin>
+                <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
+                <plugin>
+                    <artifactId>maven-resources-plugin</artifactId>
+                    <version>3.0.2</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <version>3.7.0</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-surefire-plugin</artifactId>
+                    <version>2.20.1</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-jar-plugin</artifactId>
+                    <version>3.0.2</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-install-plugin</artifactId>
+                    <version>2.5.2</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-deploy-plugin</artifactId>
+                    <version>2.8.2</version>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+</project>

nacos-selector-plugin-exmaple/src/main/java/com/alibaba/nacos/exmaple/selector/plugin/ExampleCmdbSelector.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.nacos.exmaple.selector.plugin;
+
+import com.alibaba.nacos.api.exception.NacosException;
+import com.alibaba.nacos.api.naming.pojo.Instance;
+import com.alibaba.nacos.api.selector.AbstractCmdbSelector;
+import com.alibaba.nacos.api.selector.context.CmdbContext;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Example use of selector.
+ *
+ * @author chenglu
+ * @date 2021-08-09 19:33
+ */
+public class ExampleCmdbSelector extends AbstractCmdbSelector<Instance> {
+
+    private List<String> tags = new ArrayList<>();
+
+    public List<String> getTags() {
+        return tags;
+    }
+
+    public void setTags(List<String> tags) {
+        this.tags = tags;
+    }
+
+    @Override
+    protected List<Instance> doSelect(CmdbContext<Instance> context) {
+        return context.getProviders().stream()
+                .filter(ci -> tags.contains(ci.getEntity().getName()))
+                .map(CmdbContext.CmdbInstance::getInstance)
+                .collect(Collectors.toList());
+    }
+
+    @Override
+    protected void doParse(String expression) throws NacosException {
+        tags.addAll(Arrays.asList(expression.split(",")));
+    }
+
+    @Override
+    public String getType() {
+        return "example";
+    }
+}

nacos-selector-plugin-exmaple/src/main/java/com/alibaba/nacos/exmaple/selector/plugin/tag/TagContext.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 1999-2021 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.nacos.exmaple.selector.plugin.tag;
+
+import com.alibaba.nacos.api.naming.pojo.Instance;
+
+import java.util.List;
+
+/**
+ * @author chenglu
+ * @date 2021-10-09 18:05
+ */
+public class TagContext {
+
+    private List<TagInstance> tagInstances;
+
+    public List<TagInstance> getTagInstances() {
+        return tagInstances;
+    }
+
+    public void setTagInstances(List<TagInstance> tagInstances) {
+        this.tagInstances = tagInstances;
+    }
+
+    static class TagInstance {
+        private Instance instance;
+
+        private String tag;
+
+        public Instance getInstance() {
+            return instance;
+        }
+
+        public void setInstance(Instance instance) {
+            this.instance = instance;
+        }
+
+        public String getTag() {
+            return tag;
+        }
+
+        public void setTag(String tag) {
+            this.tag = tag;
+        }
+    }
+}

nacos-selector-plugin-exmaple/src/main/java/com/alibaba/nacos/exmaple/selector/plugin/tag/TagContextBuilder.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 1999-2021 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.nacos.exmaple.selector.plugin.tag;
+
+import com.alibaba.nacos.api.naming.pojo.Instance;
+import com.alibaba.nacos.api.selector.context.SelectorContextBuilder;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * @author chenglu
+ * @date 2021-10-09 18:08
+ */
+public class TagContextBuilder implements SelectorContextBuilder<TagContext, String, List<Instance>> {
+
+    @Override
+    public TagContext build(String consumer, List<Instance> provider) {
+        TagContext tagContext = new TagContext();
+        List<TagContext.TagInstance> tagInstances = provider.stream()
+                .map(i -> {
+                    TagContext.TagInstance tagInstance = new TagContext.TagInstance();
+                    tagInstance.setInstance(i);
+                    if (i.getIp().equals("127.0.0.1")) {
+                        tagInstance.setTag("A");
+                    } else {
+                        tagInstance.setTag("B");
+                    }
+                    return tagInstance;
+                })
+                .collect(Collectors.toList());
+        tagContext.setTagInstances(tagInstances);
+        return tagContext;
+    }
+
+    @Override
+    public String getContextType() {
+        return "TAG";
+    }
+}

nacos-selector-plugin-exmaple/src/main/java/com/alibaba/nacos/exmaple/selector/plugin/tag/TagSelector.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 1999-2021 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.nacos.exmaple.selector.plugin.tag;
+
+import com.alibaba.nacos.api.exception.NacosException;
+import com.alibaba.nacos.api.naming.pojo.Instance;
+import com.alibaba.nacos.api.selector.Selector;
+import com.alibaba.nacos.api.utils.StringUtils;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * @author chenglu
+ * @date 2021-10-09 18:05
+ */
+public class TagSelector implements Selector<List<Instance>, TagContext, String> {
+
+    List<String> tags = new ArrayList<>();
+
+    public List<String> getTags() {
+        return tags;
+    }
+
+    public void setTags(List<String> tags) {
+        this.tags = tags;
+    }
+
+    private String expression;
+
+    public String getExpression() {
+        return expression;
+    }
+
+    public void setExpression(String expression) {
+        this.expression = expression;
+    }
+
+    @Override
+    public Selector<List<Instance>, TagContext, String> parse(String expression) throws NacosException {
+        if (StringUtils.isBlank(expression)) {
+            return this;
+        }
+        this.expression = expression;
+        tags.addAll(Arrays.asList(expression.split(",")));
+        return this;
+    }
+
+    @Override
+    public List<Instance> select(TagContext context) {
+        return context.getTagInstances().stream()
+                .filter(tagInstance -> tags.contains(tagInstance.getTag()))
+                .map(TagContext.TagInstance::getInstance)
+                .collect(Collectors.toList());
+    }
+
+    @Override
+    public String getType() {
+        return "tag";
+    }
+
+    @Override
+    public String getContextType() {
+        return "TAG";
+    }
+}

nacos-selector-plugin-exmaple/src/main/resources/META-INF/services/com.alibaba.nacos.api.selector.Selector

@@ -0,0 +1,16 @@
+# Copyright 1999-2021 Alibaba Group Holding Ltd.
+#
+# 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.
+
+com.alibaba.nacos.exmaple.selector.plugin.ExampleCmdbSelector
+com.alibaba.nacos.exmaple.selector.plugin.tag.TagSelector

nacos-selector-plugin-exmaple/src/main/resources/META-INF/services/com.alibaba.nacos.api.selector.context.SelectorContextBuilder

@@ -0,0 +1,15 @@
+# Copyright 1999-2021 Alibaba Group Holding Ltd.
+#
+# 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.
+
+com.alibaba.nacos.exmaple.selector.plugin.tag.TagContextBuilder