[ISSUE #14077] Implement SPI-based plugin discovery and management API

api/src/main/java/com/alibaba/nacos/api/plugin/ConfigItemDefinition.java

@@ -0,0 +1,167 @@
+/*
+ * Copyright 1999-2024 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.api.plugin;
+
+import java.io.Serializable;
+import java.util.List;
+
+/**
+ * Plugin configuration item definition.
+ *
+ * @author WangzJi
+ * @since 3.2.0
+ */
+public class ConfigItemDefinition implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Configuration key.
+     */
+    private String key;
+
+    /**
+     * Display name.
+     */
+    private String name;
+
+    /**
+     * Description.
+     */
+    private String description;
+
+    /**
+     * Default value.
+     */
+    private String defaultValue;
+
+    /**
+     * Configuration item type.
+     */
+    private ConfigItemType type;
+
+    /**
+     * Whether this item is required.
+     */
+    private boolean required;
+
+    /**
+     * Enum values (when type is ENUM).
+     */
+    private List<String> enumValues;
+
+    public ConfigItemDefinition() {
+    }
+
+    public ConfigItemDefinition(String key, String name, ConfigItemType type) {
+        this.key = key;
+        this.name = name;
+        this.type = type;
+    }
+
+    public String getKey() {
+        return key;
+    }
+
+    public void setKey(String key) {
+        this.key = key;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public String getDefaultValue() {
+        return defaultValue;
+    }
+
+    public void setDefaultValue(String defaultValue) {
+        this.defaultValue = defaultValue;
+    }
+
+    public ConfigItemType getType() {
+        return type;
+    }
+
+    public void setType(ConfigItemType type) {
+        this.type = type;
+    }
+
+    public boolean isRequired() {
+        return required;
+    }
+
+    public void setRequired(boolean required) {
+        this.required = required;
+    }
+
+    public List<String> getEnumValues() {
+        return enumValues;
+    }
+
+    public void setEnumValues(List<String> enumValues) {
+        this.enumValues = enumValues;
+    }
+
+    /**
+     * Builder for ConfigItemDefinition.
+     */
+    public static class Builder {
+
+        private final ConfigItemDefinition definition;
+
+        public Builder(String key, String name, ConfigItemType type) {
+            this.definition = new ConfigItemDefinition(key, name, type);
+        }
+
+        public Builder description(String description) {
+            definition.setDescription(description);
+            return this;
+        }
+
+        public Builder defaultValue(String defaultValue) {
+            definition.setDefaultValue(defaultValue);
+            return this;
+        }
+
+        public Builder required(boolean required) {
+            definition.setRequired(required);
+            return this;
+        }
+
+        public Builder enumValues(List<String> enumValues) {
+            definition.setEnumValues(enumValues);
+            return this;
+        }
+
+        public ConfigItemDefinition build() {
+            return definition;
+        }
+    }
+}

api/src/main/java/com/alibaba/nacos/api/plugin/ConfigItemType.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 1999-2024 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.api.plugin;
+
+/**
+ * Configuration item type enumeration.
+ *
+ * @author WangzJi
+ * @since 3.2.0
+ */
+public enum ConfigItemType {
+
+    /**
+     * String type configuration.
+     */
+    STRING,
+
+    /**
+     * Number type configuration.
+     */
+    NUMBER,
+
+    /**
+     * Boolean type configuration.
+     */
+    BOOLEAN,
+
+    /**
+     * Enumeration type configuration.
+     */
+    ENUM
+}

api/src/main/java/com/alibaba/nacos/api/plugin/PluginConfigSpec.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 1999-2024 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.api.plugin;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Plugin configuration specification interface.
+ * Allows plugins to declare configurable properties.
+ *
+ * @author WangzJi
+ * @since 3.2.0
+ */
+public interface PluginConfigSpec {
+
+    /**
+     * Get configuration item definitions.
+     *
+     * @return list of configuration item definitions
+     */
+    List<ConfigItemDefinition> getConfigDefinitions();
+
+    /**
+     * Apply configuration to the plugin.
+     *
+     * @param config configuration key-value pairs
+     */
+    void applyConfig(Map<String, String> config);
+
+    /**
+     * Get current configuration.
+     *
+     * @return current configuration as key-value pairs
+     */
+    Map<String, String> getCurrentConfig();
+}

api/src/main/java/com/alibaba/nacos/api/plugin/PluginProvider.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 1999-2024 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.api.plugin;
+
+import java.util.Map;
+
+/**
+ * Plugin provider SPI interface.
+ *
+ * <p>Each plugin type should have one implementation to provide plugin instances.
+ * This interface enables automatic plugin discovery through SPI mechanism,
+ * eliminating the need to manually register each plugin type in UnifiedPluginManager.
+ *
+ * <p>Example implementation:
+ * <pre>{@code
+ * public class AuthPluginProvider implements PluginProvider<AuthPluginService> {
+ *     @Override
+ *     public PluginType getPluginType() {
+ *         return PluginType.AUTH;
+ *     }
+ *
+ *     @Override
+ *     public Map<String, AuthPluginService> getAllPlugins() {
+ *         return AuthPluginManager.getInstance().getAllPlugins();
+ *     }
+ * }
+ * }</pre>
+ *
+ * @param <T> the plugin service type
+ * @author WangzJi
+ * @since 3.2.0
+ */
+public interface PluginProvider<T> {
+
+    /**
+     * Get the plugin type this provider manages.
+     *
+     * @return plugin type
+     */
+    PluginType getPluginType();
+
+    /**
+     * Get all plugin instances managed by this provider.
+     * Key is the plugin name, value is the plugin instance.
+     *
+     * @return map of plugin name to plugin instance
+     */
+    Map<String, T> getAllPlugins();
+
+    /**
+     * Get the order of this provider. Lower values have higher priority.
+     * Used when multiple providers exist for same type.
+     *
+     * @return order value, default is 0
+     */
+    default int getOrder() {
+        return 0;
+    }
+}

api/src/main/java/com/alibaba/nacos/api/plugin/PluginStateChecker.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 1999-2024 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.api.plugin;
+
+/**
+ * Plugin state checker interface.
+ * Used to decouple plugin managers from core module.
+ *
+ * @author WangzJi
+ * @since 3.0.0
+ */
+public interface PluginStateChecker {
+
+    /**
+     * Check if plugin is enabled.
+     *
+     * @param pluginType plugin type string
+     * @param pluginName plugin name
+     * @return true if plugin is enabled, false otherwise
+     */
+    boolean isPluginEnabled(String pluginType, String pluginName);
+}