NIFI-15480: Added ability to drop FlowFiles selectively using a Predi…

.cursorrules

@@ -0,0 +1,74 @@
+AI persona
+----------
+Act as an experienced Java software engineer. When considering how to implement a task, first consider the big picture of what is being asked. Then determine which classes will need to be udpated.
+Quite often, a single request will require manipulating many different classes. Generally speaking, it is best to avoid changing established interfaces, but it is often acceptable because the public API
+that NiFi adheres to is not in this module.
+
+
+API
+---
+When it is necessary to lookup the API for reference, the API can generally be found at ../nifi-api, where .. is relative to the project's root directory.
+
+Building
+--------
+NiFi is a complex Maven codebase. Never build code (testing or otherwise) using javac. Always use `mvn` instead.
+Additionally, building a maven module using the also-make flag (`-am`) is often very expensive and slow.
+Instead, only build the specific module you are modifying. Assume that the user has already built the entire
+codebase and that only the specific module you are modifying needs to be built again.
+
+Code Style
+----------
+NiFi adheres to a few code styles that are not necessarily common. Please ensure that you observe these code styles.
+1. Any variable that can be marked `final` must be marked `final`. This includes declarations of Exceptions, method arguments, local variables, member variables, etc.
+2. Short-hand is highly discouraged in names of variables, classes, methods, etc., as well as in documentation.
+3. Private / helper methods should not be placed before the first public/protected method that calls it.
+4. Unless the method is to be heavily reused, avoid creating trivial 1-2 line methods and instead just place the code inline.
+5. Code is allowed to be up to 200 characters wide. Avoid breaking lines into many short lines.
+6. Avoid creating private methods that are called only once unless they are at least 10 lines long or are complex.
+7. It is never acceptable to use star imports. Import each individual class that is to be used.
+8. Never use underscores in class names, variables, or filenames.
+9. Never use System.out.println but instead use SLF4J Loggers
+10. Avoid excessive whitespace in method invocations. For example, instead of writing:
+```
+myObject.doSomething(
+  arg1,
+  arg2,
+  arg3,
+  arg4,
+  arg5
+);
+```
+Write this instead:
+```
+myObject.doSomething(arg1, arg2, arg3, arg4, arg5);
+```
+
+11. When possible, prefer importing a class, rather than using fully qualified classname inline in the code.
+12. Avoid statically importing methods unless they are used frequently such as methods in the `Assertions` and `Mockito` classes.
+13. Avoid trailing whitespace at the end of lines, especially in blank lines.
+
+Unit / Automated Testing
+------------------------
+In addition to the general rules defined in the Code Style section, follow these rules when creating or manipulating automated tests.
+1. NEVER add comments such as `// Given`, `// When`, `// Then`. These comments are considered an anti-pattern and should be removed or replaced whenever they are encountered.
+   Instead, leave them out all together (preferred) or use comments that clearly articulate what is happening, such as `// Setup`, `// Invoke method`, `// Assert expected results.`
+   One of the reasons that this is considered an anti-pattern (in addition to the fact that the given/when/then nomeclature itself provides no meaning) is that it assumes a very specific pattern
+   in unit tests, that we will create a bunch of objects, invoke the method we care about, make assertions, and then end. This often results in many tests that are extremely repetitive.
+   Instead, whenever it makes sense to do so, create the prerequisitive objects, invoke the method we care about with appropriate arguments, make assertions, and then invoke again with a different
+   set of arguments, make assertions, etc. There is no need to have many repetitive methods that each create many repetitive objects.
+
+2. Unit tests are Java. They are not English. As such, they should be written like Java. Frameworks such as assertj that strive to make the unit tests look more "English-like" should be avoided.
+   Use of these frameworks sometimes works well but often quickly devolves into automated tests that read like neither English nor Java.
+
+3. Like any other code, unit tests should be created using reusable methods where appropriate. Do not create 15 methods that are all very similar and repetitive. Instead, create reusable methods
+   that can be called from each of the methods.
+
+4. Never use the `assert` keyword. Use JUnit assertions instead.
+
+5. Never create a test file that is centered around testing a method or capability. Unit tests must always be named after the class they are testing. It is okay if a given unit test class is very, very long.
+
+6. This is a Java project using the Maven structure. Java test files must always fall under src/test/java of the appropriate sub-module.
+
+7. Never use pointless assertions such as assertDoesNotThrow - this adds nothing but complexity. Just call the method, and if it throws an Exception, the test will fail. I.e.,
+   it is assumed by default that each line does not throw an Exception, so do not use
+

c2/c2-protocol/c2-protocol-component-api/src/main/java/org/apache/nifi/c2/protocol/component/api/ComponentManifest.java

@@ -33,6 +33,7 @@ public class ComponentManifest implements Serializable {
     private List<ParameterProviderDefinition> parameterProviders;
     private List<FlowRegistryClientDefinition> flowRegistryClients;
     private List<FlowAnalysisRuleDefinition> flowAnalysisRules;
+    private List<ConnectorDefinition> connectors;
 
     @Schema(description = "Public interfaces defined in this bundle")
     public List<DefinedType> getApis() {
@@ -97,4 +98,13 @@ public void setFlowRegistryClients(List<FlowRegistryClientDefinition> flowRegist
         this.flowRegistryClients = flowRegistryClients;
     }
 
+    @Schema(description = "Connectors provided in this bundle")
+    public List<ConnectorDefinition> getConnectors() {
+        return (connectors != null ? Collections.unmodifiableList(connectors) : null);
+    }
+
+    public void setConnectors(List<ConnectorDefinition> connectors) {
+        this.connectors = connectors;
+    }
+
 }

c2/c2-protocol/c2-protocol-component-api/src/main/java/org/apache/nifi/c2/protocol/component/api/ConfigurationStep.java

@@ -0,0 +1,81 @@
+/*
+ * 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.nifi.c2.protocol.component.api;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.io.Serializable;
+import java.util.List;
+
+/**
+ * Represents a configuration step for a Connector.
+ */
+public class ConfigurationStep implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private String name;
+    private String description;
+    private boolean documented;
+    private List<ConfigurationStepDependency> stepDependencies;
+    private List<ConnectorPropertyGroup> propertyGroups;
+
+    @Schema(description = "The name of the configuration step")
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Schema(description = "The description of the configuration step")
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    @Schema(description = "Whether this configuration step has additional documentation")
+    public boolean isDocumented() {
+        return documented;
+    }
+
+    public void setDocumented(boolean documented) {
+        this.documented = documented;
+    }
+
+    @Schema(description = "The dependencies that this step has on other steps")
+    public List<ConfigurationStepDependency> getStepDependencies() {
+        return stepDependencies;
+    }
+
+    public void setStepDependencies(List<ConfigurationStepDependency> stepDependencies) {
+        this.stepDependencies = stepDependencies;
+    }
+
+    @Schema(description = "The property groups in this configuration step")
+    public List<ConnectorPropertyGroup> getPropertyGroups() {
+        return propertyGroups;
+    }
+
+    public void setPropertyGroups(List<ConnectorPropertyGroup> propertyGroups) {
+        this.propertyGroups = propertyGroups;
+    }
+}
+

c2/c2-protocol/c2-protocol-component-api/src/main/java/org/apache/nifi/c2/protocol/component/api/ConfigurationStepDependency.java

@@ -0,0 +1,61 @@
+/*
+ * 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.nifi.c2.protocol.component.api;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.io.Serializable;
+import java.util.List;
+
+/**
+ * Represents a dependency that a configuration step has on another step's property.
+ */
+public class ConfigurationStepDependency implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private String stepName;
+    private String propertyName;
+    private List<String> dependentValues;
+
+    @Schema(description = "The name of the step that this step depends on")
+    public String getStepName() {
+        return stepName;
+    }
+
+    public void setStepName(String stepName) {
+        this.stepName = stepName;
+    }
+
+    @Schema(description = "The name of the property within the step that this step depends on")
+    public String getPropertyName() {
+        return propertyName;
+    }
+
+    public void setPropertyName(String propertyName) {
+        this.propertyName = propertyName;
+    }
+
+    @Schema(description = "The values of the dependent property that enable this step")
+    public List<String> getDependentValues() {
+        return dependentValues;
+    }
+
+    public void setDependentValues(List<String> dependentValues) {
+        this.dependentValues = dependentValues;
+    }
+}
+

c2/c2-protocol/c2-protocol-component-api/src/main/java/org/apache/nifi/c2/protocol/component/api/ConnectorDefinition.java

@@ -0,0 +1,41 @@
+/*
+ * 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.nifi.c2.protocol.component.api;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Definition of a Connector component.
+ */
+public class ConnectorDefinition extends ExtensionComponent {
+    private static final long serialVersionUID = 1L;
+
+    private List<ConfigurationStep> configurationSteps;
+
+    @Schema(description = "The configuration steps for this connector")
+    public List<ConfigurationStep> getConfigurationSteps() {
+        return (configurationSteps != null ? Collections.unmodifiableList(configurationSteps) : null);
+    }
+
+    public void setConfigurationSteps(List<ConfigurationStep> configurationSteps) {
+        this.configurationSteps = configurationSteps;
+    }
+}
+

c2/c2-protocol/c2-protocol-component-api/src/main/java/org/apache/nifi/c2/protocol/component/api/ConnectorPropertyDependency.java

@@ -0,0 +1,51 @@
+/*
+ * 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.nifi.c2.protocol.component.api;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+import java.io.Serializable;
+import java.util.List;
+
+/**
+ * Represents a dependency that a connector property has on another property.
+ */
+public class ConnectorPropertyDependency implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private String propertyName;
+    private List<String> dependentValues;
+
+    @Schema(description = "The name of the property that this property depends on")
+    public String getPropertyName() {
+        return propertyName;
+    }
+
+    public void setPropertyName(String propertyName) {
+        this.propertyName = propertyName;
+    }
+
+    @Schema(description = "The values of the dependent property that enable this property")
+    public List<String> getDependentValues() {
+        return dependentValues;
+    }
+
+    public void setDependentValues(List<String> dependentValues) {
+        this.dependentValues = dependentValues;
+    }
+}
+