在開發項目中,我們經常會需要打印日誌,這樣方便開發人員瞭解接口調用情況及定位錯誤問題,很多時候對於Controller或者是Service的入參
和出參
需要打印日誌,但是我們又不想重複的在每個方法裏去使用logger
打印,這個時候希望有一個管理者統一來打印,這時Spring AOP就派上用場了,利用切面的思想,我們在進入、出入Controller或Service時給它切一刀
實現統一日誌打印。
SpringAOP不僅可以實現在不產生新類的情況下打印日誌,還可以管理事務、緩存等。具體可以瞭解官方文檔。https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#aop-api
基礎概念
在使用SpringAOP,這裏還是先簡單講解一些基本的知識吧,如果說的不對請及時指正,這裏主要是根據官方文檔來總結的。本章內容主要涉及的知識點。
Pointcut: 切入點,這裏用於定義規則,進行方法的切入(形象的比喻就是一把刀)。
JoinPoint: 連接點,用於連接定義的切面。
Before: 在之前,在切入點方法執行之前。
AfterReturning: 在切入點方法結束並返回時執行。
這裏除了SpringAOP相關的知識,還涉及到了線程相關的知識點,因爲我們需要考慮多線程中它們各自需要保存自己的變量,所以就用到了ThreadLocal
。
依賴引入
這裏主要是用到aop
和mongodb
,在pom.xml
文件中加入以下依賴即可:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
相關實體類
/**
* 請求日誌實體,用於保存請求日誌
*/
@Document
class WebLog {
var id: String = ""
var request: String? = null
var response: String? = null
var time: Long? = null
var requestUrl: String? = null
var requestIp: String? = null
var startTime: Long? = null
var endTime: Long? = null
var method: String? = null
override fun toString(): String {
return ObjectMapper().writeValueAsString(this)
}
}
/**
* 業務對象,上一章講JPA中有定義
*/
@Document
class Student {
@Id
var id :String? = null
var name :String? = null
var age :Int? = 0
var gender :String? = null
var sclass :String ?= null
override fun toString(): String {
return ObjectMapper().writeValueAsString(this)
}
}
定義切面
定義切入點
/**
* 定義一個切入,只要是爲io.intodream..web下public修飾的方法都要切入
*/
@Pointcut(value = "execution(public * io.intodream..web.*.*(..))")
fun webLog() {}
定義切入點的表達式還可以使用within
、如:
/**
* 表示在io.intodream.web包下的方法都會被切入
*/
@Pointcut(value = "within(io.intodream.web..*")
定義一個連接點
/**
* 切面的連接點,並聲明在該連接點進入之前需要做的一些事情
*/
@Before(value = "webLog()")
@Throws(Throwable::class)
fun doBefore(joinPoint: JoinPoint) {
val webLog = WebLog()
webLog.startTime = System.currentTimeMillis()
val attributes = RequestContextHolder.getRequestAttributes() as ServletRequestAttributes?
val request = attributes!!.request
val args = joinPoint.args
val paramNames = (joinPoint.signature as CodeSignature).parameterNames
val params = HashMap<String, Any>(args.size)
for (i in args.indices) {
if (args[i] !is BindingResult) {
params[paramNames[i]] = args[i]
}
}
webLog.id = UUID.randomUUID().toString()
webLog.request = params.toString()
webLog.requestUrl = request.requestURI.toString()
webLog.requestIp = request.remoteAddr
webLog.method = request.method
webRequestLog.set(webLog)
logger.info("REQUEST={} {}; SOURCE IP={}; ARGS={}", request.method,
request.requestURL.toString(), request.remoteAddr, params)
}
方法結束後執行
@AfterReturning(returning = "ret", pointcut = "webLog()")
@Throws(Throwable::class)
fun doAfterReturning(ret: Any) {
val webLog = webRequestLog.get()
webLog.response = ret.toString()
webLog.endTime = System.currentTimeMillis()
webLog.time = webLog.endTime!! - webLog.startTime!!
logger.info("RESPONSE={}; SPEND TIME={}MS", ObjectMapper().writeValueAsString(ret), webLog.time)
logger.info("webLog:{}", webLog)
webLogRepository.save(webLog)
webRequestLog.remove()
}
這裏的主要思路是,在方法執行前,先記錄詳情的請求參數,請求方法,請求ip, 請求方式及進入時間,然後將對象放入到ThreadLocal
中,在方法結束後並取到對應的返回對象且計算出請求耗時,然後將請求日誌保存到mongodb
中。
完成的代碼
package io.intodream.kotlin07.aspect
import com.fasterxml.jackson.databind.ObjectMapper
import io.intodream.kotlin07.dao.WebLogRepository
import io.intodream.kotlin07.entity.WebLog
import org.aspectj.lang.JoinPoint
import org.aspectj.lang.annotation.AfterReturning
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.Before
import org.aspectj.lang.annotation.Pointcut
import org.aspectj.lang.reflect.CodeSignature
import org.slf4j.Logger
import org.slf4j.LoggerFactory
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.core.annotation.Order
import org.springframework.stereotype.Component
import org.springframework.validation.BindingResult
import org.springframework.web.context.request.RequestContextHolder
import org.springframework.web.context.request.ServletRequestAttributes
import java.util.*
/**
* {描述}
*
* @author [email protected]
* @date 2019/4/10 19:06
*
*/
@Aspect
@Order(5)
@Component
class WebLogAspect {
private val logger:Logger = LoggerFactory.getLogger(WebLogAspect::class.java)
private val webRequestLog: ThreadLocal<WebLog> = ThreadLocal()
@Autowired lateinit var webLogRepository: WebLogRepository
/**
* 定義一個切入,只要是爲io.intodream..web下public修飾的方法都要切入
*/
@Pointcut(value = "execution(public * io.intodream..web.*.*(..))")
fun webLog() {}
/**
* 切面的連接點,並聲明在該連接點進入之前需要做的一些事情
*/
@Before(value = "webLog()")
@Throws(Throwable::class)
fun doBefore(joinPoint: JoinPoint) {
val webLog = WebLog()
webLog.startTime = System.currentTimeMillis()
val attributes = RequestContextHolder.getRequestAttributes() as ServletRequestAttributes?
val request = attributes!!.request
val args = joinPoint.args
val paramNames = (joinPoint.signature as CodeSignature).parameterNames
val params = HashMap<String, Any>(args.size)
for (i in args.indices) {
if (args[i] !is BindingResult) {
params[paramNames[i]] = args[i]
}
}
webLog.id = UUID.randomUUID().toString()
webLog.request = params.toString()
webLog.requestUrl = request.requestURI.toString()
webLog.requestIp = request.remoteAddr
webLog.method = request.method
webRequestLog.set(webLog)
logger.info("REQUEST={} {}; SOURCE IP={}; ARGS={}", request.method,
request.requestURL.toString(), request.remoteAddr, params)
}
@AfterReturning(returning = "ret", pointcut = "webLog()")
@Throws(Throwable::class)
fun doAfterReturning(ret: Any) {
val webLog = webRequestLog.get()
webLog.response = ret.toString()
webLog.endTime = System.currentTimeMillis()
webLog.time = webLog.endTime!! - webLog.startTime!!
logger.info("RESPONSE={}; SPEND TIME={}MS", ObjectMapper().writeValueAsString(ret), webLog.time)
logger.info("webLog:{}", webLog)
webLogRepository.save(webLog)
webRequestLog.remove()
}
}
這裏定義的是Web層的切面,對於Service層我也可以定義一個切面,但是對於Service層的進入和返回的日誌我們可以把級別稍等調低一點,這裏改debug
,具體實現如下:
package io.intodream.kotlin07.aspect
import com.fasterxml.jackson.databind.ObjectMapper
import org.aspectj.lang.JoinPoint
import org.aspectj.lang.annotation.AfterReturning
import org.aspectj.lang.annotation.Aspect
import org.aspectj.lang.annotation.Before
import org.aspectj.lang.annotation.Pointcut
import org.aspectj.lang.reflect.CodeSignature
import org.slf4j.Logger
import org.slf4j.LoggerFactory
import org.springframework.core.annotation.Order
import org.springframework.stereotype.Component
import org.springframework.validation.BindingResult
/**
* service層所有public修飾的方法調用返回日誌
*
* @author [email protected]
* @date 2019/4/10 17:33
*
*/
@Aspect
@Order(2)
@Component
class ServiceLogAspect {
private val logger: Logger = LoggerFactory.getLogger(ServiceLogAspect::class.java)
/**
*
*/
@Pointcut(value = "execution(public * io.intodream..service.*.*(..))")
private fun serviceLog(){}
@Before(value = "serviceLog()")
fun deBefore(joinPoint: JoinPoint) {
val args = joinPoint.args
val codeSignature = joinPoint.signature as CodeSignature
val paramNames = codeSignature.parameterNames
val params = HashMap<String, Any>(args.size).toMutableMap()
for (i in args.indices) {
if (args[i] !is BindingResult) {
params[paramNames[i]] = args[i]
}
}
logger.debug("CALL={}; ARGS={}", joinPoint.signature.name, params)
}
@AfterReturning(returning = "ret", pointcut = "serviceLog()")
@Throws(Throwable::class)
fun doAfterReturning(ret: Any) {
logger.debug("RESPONSE={}", ObjectMapper().writeValueAsString(ret))
}
}
接口測試
這裏就不在貼出Service層和web的代碼實現了,因爲我是拷貝之前將JPA那一章的代碼,唯一不同的就是加入了切面,切面的加入並不影響原來的業務流程。
執行如下請求:
我們會在控制檯看到如下日誌
2019-04-14 19:32:27.208 INFO 4914 --- [nio-9000-exec-1] i.i.kotlin07.aspect.WebLogAspect : REQUEST=POST http://localhost:9000/api/student/; SOURCE IP=0:0:0:0:0:0:0:1; ARGS={student={"id":"5","name":"Rose","age":17,"gender":"Girl","sclass":"Second class"}}
2019-04-14 19:32:27.415 INFO 4914 --- [nio-9000-exec-1] org.mongodb.driver.connection : Opened connection [connectionId{localValue:2, serverValue:4}] to localhost:27017
2019-04-14 19:32:27.431 INFO 4914 --- [nio-9000-exec-1] i.i.kotlin07.aspect.WebLogAspect : RESPONSE={"id":"5","name":"Rose","age":17,"gender":"Girl","sclass":"Second class"}; SPEND TIME=239MS
2019-04-14 19:32:27.431 INFO 4914 --- [nio-9000-exec-1] i.i.kotlin07.aspect.WebLogAspect : webLog:{"id":"e7b0ca1b-0a71-4fa0-9f5f-95a29d4d54a1","request":"{student={\"id\":\"5\",\"name\":\"Rose\",\"age\":17,\"gender\":\"Girl\",\"sclass\":\"Second class\"}}","response":"{\"id\":\"5\",\"name\":\"Rose\",\"age\":17,\"gender\":\"Girl\",\"sclass\":\"Second class\"}","time":239,"requestUrl":"/api/student/","requestIp":"0:0:0:0:0:0:0:1","startTime":1555241547191,"endTime":1555241547430,"method":"POST"}
查看數據庫會看到我們的請求日誌已經寫入了:
這裏有一個地方需要注意,在Service層的實現,具體如下:
return studentRepository.findById(id).get()
這裏的findById
會返回一個Optional<T>
對象,如果沒有查到數據,我們使用get
獲取數據會出現異常java.util.NoSuchElementException: No value present
,可以改爲返回對象可以爲空只要在返回類型後面加一個?
即可,同時調用Optional
的ifPresent
進行安全操作。