java Spring MongoRepository转换POJO非常慢
问题说明
我的RESTAPI有一个很大的性能问题。 我在谷歌上找不到任何帮助，所以我在这里问我的问题
我可以针对缓慢的查询，但这不是因为查询本身，因为当我直接在Compass中运行它时，需要0毫秒
我认为问题在于Java，当它将查询结果转换为POJO时，如何改进它
项目设置和代码
波姆。xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com</groupId>
<artifactId>myproject</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>myproject</name>
<description>myproject API</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>com.newrelic.agent.java</groupId>
<artifactId>newrelic-java</artifactId>
<version>5.12.1</version>
<scope>provided</scope>
<type>zip</type>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-oauth2-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-oauth2-resource-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.session</groupId>
<artifactId>spring-session-core</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.auth</groupId>
<artifactId>google-auth-library-oauth2-http</artifactId>
<version>0.16.1</version>
</dependency>
<dependency>
<groupId>com.google.firebase</groupId>
<artifactId>firebase-admin</artifactId>
<version>6.9.0</version>
</dependency>
<dependency>
<groupId>io.swagger</groupId>
<artifactId>swagger-annotations</artifactId>
<version>1.5.14</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.passay</groupId>
<artifactId>passay</artifactId>
<version>1.6.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>3.0.2</version>
<executions>
<execution>
<id>unpack-newrelic</id>
<phase>package</phase>
<goals>
<goal>unpack-dependencies</goal>
</goals>
<configuration>
<includeGroupIds>com.newrelic.agent.java</includeGroupIds>
<includeArtifactIds>newrelic-java</includeArtifactIds>
<overWriteReleases>false</overWriteReleases>
<overWriteSnapshots>false</overWriteSnapshots>
<overWriteIfNewer>true</overWriteIfNewer>
<outputDirectory>${project.basedir}</outputDirectory>
<destFileName>newrelic</destFileName>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
项目。爪哇
/*
* Copyright (C) 2020
* Produced by Wuidev
*/
package com.myproject.api.model;
import lombok.Data;
import org.springframework.data.annotation.Id;
@Data
public class Item {
@Id
private String id;
}
MenuChoice。爪哇
/*
* Copyright (C) 2020
* Produced by Wuidev
*/
package com.myproject.api.model;
import lombok.Data;
import lombok.EqualsAndHashCode;
import org.springframework.data.mongodb.core.index.Indexed;
import org.springframework.data.mongodb.core.mapping.DBRef;
import java.util.List;
@Data
@EqualsAndHashCode(callSuper = false)
public class MenuChoice extends Item {
// private String customerId;
@DBRef
private Customer customer;
@Indexed
@DBRef
private Menu menu;
// private String menuId;
private List<MenuItemChoice> choices;
private String comment;
private String timeSlot;
}
Menuchoicepository。爪哇
package com.myproject.api.dao;
import com.myproject.api.model.Menu;
import com.myproject.api.model.MenuChoice;
import org.springframework.data.mongodb.repository.MongoRepository;
import java.util.List;
/**
* The interface Menu choice repository.
*/
public interface MenuChoiceRepository extends MongoRepository<MenuChoice, String> {
/**
* Find all by menu list.
*
* @param menu the menu
* @return the list
*/
List<MenuChoice> findAllByMenu(Menu menu);
}
DefaultMenuChoiceService
@Component
public class DefaultMenuChoiceService extends AbstractDefaultItemService<MenuChoice> implements MenuChoiceService {
@Override
public List<MenuChoice> getChoicesForMenu(final Menu m) {
final long startTime = System.currentTimeMillis();
if(m == null) {
return Collections.emptyList();
}
final List<MenuChoice> choices = menuChoiceRepository.findAllByMenu(m);
// final List<MenuChoice> choices = menuChoiceRepository.findAllByMenu_Id(m.getId());
LOG.info("getChoicesForMenu total = {}", (System.currentTimeMillis() - startTime));
return choices;
}
}
结果
我已将mongoTemplate日志记录级别设置为DEBUG，以下是查询：
find using query: { "menu" : { "$java" : { "$ref" : "menu", "$id" : "foo" } } } fields: Document{{}} for class: class com.myproject.api.model.MenuChoice in collection: menuChoice
本地环境
文件总数：22
返回的MenuChoice文档数：1
getChoicesForMenu total = 561
生产环境
菜单文档总数：341
返回的MenuChoice文档数：27
getChoicesForMenu total = 27149
尝试过的解决方案
- 在MenuChoice集合的菜单字段上添加索引
- 升级Spring启动版本
- 我试过一次又一次地关掉它
但一切都没有改变
# 1 楼答案
我怀疑你的问题在于@DBRef。我从未使用过它，但根据文档，您的查询也会从不同的集合中检索客户，菜单（即每个菜单有+2个查询，不确定SpringJPA如何处理，但由于MongoDB是NO-SQL，我怀疑这些查询是不同的）
更多详情请访问MongoDB - is DBREF necessary?
Compass中的查询速度如此之快的原因是，这些额外的查询不会被执行，而SpringJPA也会执行额外的查询，因此您有一个完整的POJO
在改进方面，您有以下选择：