org.springframework.xd.dirt.rest.ModulesController.java Source code

Introduction

Here is the source code for org.springframework.xd.dirt.rest.ModulesController.java

Source

/*
 * Copyright 2013 the original author or authors.
 *
 * 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 org.springframework.xd.dirt.rest;

import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.web.PagedResourcesAssembler;
import org.springframework.hateoas.ExposesResourceFor;
import org.springframework.hateoas.PagedResources;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.util.Assert;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.xd.dirt.module.NoSuchModuleException;
import org.springframework.xd.dirt.stream.CompositeModuleDefinitionService;
import org.springframework.xd.module.ModuleDefinition;
import org.springframework.xd.module.ModuleType;
import org.springframework.xd.rest.client.domain.DetailedModuleDefinitionResource;
import org.springframework.xd.rest.client.domain.ModuleDefinitionResource;

/**
 * Handles all Module related interactions.
 * 
 * @author Glenn Renfro
 * @author Mark Fisher
 * @author Gunnar Hillert
 * @author Eric Bottard
 */
@Controller
@RequestMapping("/modules")
@ExposesResourceFor(ModuleDefinitionResource.class)
public class ModulesController {

    private final Log logger = LogFactory.getLog(ModulesController.class);

    private final CompositeModuleDefinitionService compositeModuleDefinitionService;

    private ModuleDefinitionResourceAssembler moduleDefinitionResourceAssembler = new ModuleDefinitionResourceAssembler();

    private final DetailedModuleDefinitionResourceAssembler detailedAssembler;

    @Autowired
    public ModulesController(CompositeModuleDefinitionService compositeModuleDefinitionService,
            DetailedModuleDefinitionResourceAssembler detailedAssembler) {
        Assert.notNull(compositeModuleDefinitionService, "compositeModuleDefinitionService must not be null");
        Assert.notNull(detailedAssembler, "detailedAssembler must not be null");
        this.compositeModuleDefinitionService = compositeModuleDefinitionService;
        this.detailedAssembler = detailedAssembler;
    }

    /**
     * List Module definitions.
     */
    @RequestMapping(value = "", method = RequestMethod.GET)
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    public PagedResources<ModuleDefinitionResource> list(Pageable pageable,
            PagedResourcesAssembler<ModuleDefinition> assembler,
            @RequestParam(value = "type", required = false) ModuleType type) {
        Page<ModuleDefinition> page = compositeModuleDefinitionService.getModuleDefinitionRepository()
                .findByType(pageable, type);
        PagedResources<ModuleDefinitionResource> result = assembler.toResource(page,
                new ModuleDefinitionResourceAssembler());
        return result;
    }

    /**
     * Retrieve detailed module definition about a particular module.
     */
    @RequestMapping(value = "/{type}/{name}", method = RequestMethod.GET)
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    public DetailedModuleDefinitionResource info(@PathVariable("type") ModuleType type,
            @PathVariable("name") String name) {
        ModuleDefinition def = compositeModuleDefinitionService.getModuleDefinitionRepository()
                .findByNameAndType(name, type);
        return detailedAssembler.toResource(def);
    }

    /**
     * Create a new composite Module.
     * 
     * @param name The name of the module to create (required)
     * @param definition The module definition, expressed in the XD DSL (required)
     */
    @RequestMapping(value = "", method = RequestMethod.POST)
    @ResponseStatus(HttpStatus.CREATED)
    @ResponseBody
    public ModuleDefinitionResource save(@RequestParam("name") String name,
            @RequestParam("definition") String definition) {
        ModuleDefinition moduleDefinition = compositeModuleDefinitionService.save(name, definition);
        ModuleDefinitionResource resource = moduleDefinitionResourceAssembler.toResource(moduleDefinition);
        return resource;
    }

    /**
     * Delete a (composite) module.
     */
    @RequestMapping(value = "/{type}/{name}", method = RequestMethod.DELETE)
    @ResponseStatus(HttpStatus.OK)
    public void delete(@PathVariable("type") ModuleType type, @PathVariable("name") String name) {
        compositeModuleDefinitionService.delete(name, type);
    }

    /**
     * Retrieve the configuration file for the provided module information.
     * 
     * @param name the name of an existing resource (required)
     * @param type the type of the module (required)
     */
    @RequestMapping(value = "/{type}/{name}/definition", method = RequestMethod.GET, produces = MediaType.APPLICATION_XML_VALUE)
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    public Resource downloadDefinition(@PathVariable("type") ModuleType type, @PathVariable("name") String name) {

        final ModuleDefinition definition = this.compositeModuleDefinitionService.getModuleDefinitionRepository()
                .findByNameAndType(name, type);

        if (definition == null) {
            throw new NoSuchModuleException(name, type);
        }

        final Resource resource = definition.getResource();

        try {
            if (logger.isWarnEnabled() && resource.getFile().length() == 0) {
                logger.warn(String.format("The length of the file '%s' for module '%s' (%s) is zero.",
                        resource.getFilename(), definition.getName(), definition.getType().name()));
            }
        } catch (IOException e) {
            throw new IllegalStateException(
                    "Unable to return the file for the provided resource: " + resource.getFilename(), e);
        }

        return resource;
    }

}