13.6 SpringBoot集成Mongodb開發問題@EnableMongoRepositories路徑配置
APPLICATION FAILED TO START
Description:
Parameter 0 of constructor in com.restfeel.controller.BlogController required a bean of type 'com.restfeel.biz.BlogService' that could not be found.
Action:
Consider defining a bean of type 'com.restfeel.biz.BlogService' in your configuration.
:bootRun FAILED
FAILURE: Build failed with an exception.
- What went wrong:
Execution failed for task ':bootRun'.
代碼
package com.restfeel.service
import com.restfeel.entity.Blog
import org.springframework.data.mongodb.repository.MongoRepository
import org.springframework.data.mongodb.repository.Query
import org.springframework.data.repository.query.Param
interface BlogService : MongoRepository<Blog, String> {
@Query("{ 'title' : ?0 }")
fun findByTitle(@Param("title") title: String): Iterable<Blog>
}
package com.restfeel.controller
import com.restfeel.service.BlogService
import com.restfeel.entity.Blog
import org.springframework.boot.autoconfigure.EnableAutoConfiguration
import org.springframework.context.annotation.ComponentScan
import org.springframework.stereotype.Controller
import org.springframework.transaction.annotation.Propagation
import org.springframework.transaction.annotation.Transactional
import org.springframework.ui.Model
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.RequestParam
import org.springframework.web.bind.annotation.ResponseBody
import java.util.*
/**
* * 注意:
* 這里要使用@Controller注解
* 而不要使用@RestController
* 否則return "index";只是返回字符串"index"， 不能跳轉到index.html
*
* @RestController is a stereotype annotation that combines @ResponseBody and @Controller.
* @RestController注解相當于@ResponseBody ＋ @Controller合在一起的作用。
*/
@Controller
@EnableAutoConfiguration
@ComponentScan
@Transactional(propagation = Propagation.REQUIRES_NEW)
class BlogController(val blogService: BlogService) {
@GetMapping("/blogs.do")
fun listAll(model: Model): String {
val now = Date();
blogService.save(Blog("SpringBoot極簡教程", "XXX", "JasonChen", now, now, 0, now, "", 0))
blogService.save(Blog("SpringBoot極簡教程", "XXX", "BluceLi", now, now, 0, now, "", 0))
blogService.save(Blog("SpringBoot極簡教程", "XXX", "MichelleChen", now, now, 0, now, "", 0))
val allblogs = blogService.findAll()
model.addAttribute("blogs", allblogs)
return "jsp/blog/list"
}
@GetMapping("/listblogs")
@ResponseBody
fun listblogs(model: Model) = blogService.findAll()
@GetMapping("/findBlog")
@ResponseBody
fun findBlog(@RequestParam(value = "title") title: String) = blogService.findByTitle(title)
}
原因
@EnableMongoRepositories路徑配置問題，AbstractMongoConfiguration掃描dao層包路徑的配置要細心。
package com.restfeel.config
import com.mongodb.Mongo
import com.mongodb.MongoClient
import com.mongodb.MongoCredential
import com.mongodb.ServerAddress
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.core.env.Environment
import org.springframework.data.mongodb.config.AbstractMongoConfiguration
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories
/**
* Created by jack on 2017/3/29.
*/
@Configuration
@EnableMongoRepositories(*arrayOf("com.restfeel.dao", "com.???.???"))
class PersistenceConfig : AbstractMongoConfiguration() {
@Autowired
private val env: Environment? = null
override fun getDatabaseName(): String {
return env!!.getProperty("mongodb.name")
}
@Bean
@Throws(Exception::class)
override fun mongo(): Mongo {
return MongoClient(listOf(ServerAddress(env!!.getProperty("mongodb.host"), env!!.getProperty("mongodb.port", Int::class.java))),
listOf(MongoCredential
.createCredential(env!!.getProperty("mongodb.username"), env!!.getProperty("mongodb.name"),
env!!.getProperty("mongodb.password").toCharArray())))
}
// override fun getMappingBasePackage(): String {
// return "com.restfiddle.dao"
// }
/**
* 這地方是配置掃描繼承Repository類的所有接口類的路徑的，路徑配置錯誤，bean就不會創建了。
* 東海陳光劍 Jason Chen @蔣村花園如意苑 2017.3.30 01:41:35
*/
override fun getMappingBasePackages(): Collection<String> {
return setOf("com.restfeel.dao", "com.restfeel.service")
}
}
原理
比如說，有代碼
@Autowired
private UserDao userDao;
其中UserDao來自
public interface UserDao extends CrudRepository<User, Long>
無論在哪兒也找不到這個Bean是在哪兒定義的，但是代碼還能正常工作。@Autowired 默認找不到會報錯，再不然就是null，不會創建bean。
我們正常會推測：這是 CrudRepository導致的， CrudRepository會自動創建一個Bean。事實如此，這個是spring data jpa的功能，它會掃描Repository的子類并實現它們。
