com.bekioui.maven.plugin.client.inspector.ResourceInspector.java Source code

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Here is the source code for com.bekioui.maven.plugin.client.inspector.ResourceInspector.java

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/**
 * Copyright (C) 2016 Mehdi Bekioui (consulting@bekioui.com)
 *
 * 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.bekioui.maven.plugin.client.inspector;

import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
import java.util.StringJoiner;

import javax.lang.model.element.Modifier;

import org.apache.maven.plugin.MojoExecutionException;

import com.bekioui.maven.plugin.client.model.JavaSourceFile;
import com.bekioui.maven.plugin.client.model.Project;
import com.bekioui.maven.plugin.client.model.Resource;
import com.squareup.javapoet.ClassName;
import com.squareup.javapoet.MethodSpec;
import com.squareup.javapoet.ParameterSpec;

public class ResourceInspector {

    private static final String ARGUMENT_NAME = "arg";

    public static List<Resource> inspect(Project project, List<JavaSourceFile> javaSourceFiles)
            throws MojoExecutionException {
        try (URLClassLoader classLoader = new URLClassLoader(project.classPathsArray())) {
            List<Resource> resources = new ArrayList<>();

            for (JavaSourceFile javaSourceFile : javaSourceFiles) {
                Class<?> resourceClass = classLoader.loadClass(javaSourceFile.path());

                if (!resourceClass.isInterface()) {
                    continue;
                }

                String resourceFieldName = resourceClass.getSimpleName().substring(0, 1).toLowerCase()
                        .concat(resourceClass.getSimpleName().substring(1));

                List<MethodSpec> methods = new ArrayList<>();
                for (Method method : resourceClass.getMethods()) {
                    StringJoiner arguments = new StringJoiner(", ", "(", ")");
                    List<ParameterSpec> parameters = new ArrayList<>();
                    int count = 0;

                    for (Type type : method.getGenericParameterTypes()) {
                        String argument = ARGUMENT_NAME + count++;
                        arguments.add(argument);
                        parameters.add(ParameterSpec.builder(type, argument).build());
                    }

                    String statement = (method.getReturnType().equals(void.class) ? "" : "return ")
                            + resourceFieldName + "." + method.getName() + arguments.toString();

                    methods.add(MethodSpec.methodBuilder(method.getName()) //
                            .addModifiers(Modifier.PUBLIC) //
                            .returns(method.getGenericReturnType()) //
                            .addParameters(parameters) //
                            .addStatement(statement) //
                            .build());
                }

                resources.add(Resource.builder() //
                        .className(resourceClass.getSimpleName())//
                        .fieldName(resourceFieldName) //
                        .typeName(ClassName.get(resourceClass).box()) //
                        .methods(methods) //
                        .build());
            }

            return resources;
        } catch (IOException e) {
            throw new MojoExecutionException("Failed to initialize class loader.", e);
        } catch (ClassNotFoundException e) {
            throw new MojoExecutionException("Failed to load class.", e);
        }
    }

}