Spring Data MongoDB项目提供了与MongoDB文档数据库的集成。是Spring Data项目的一个分支。本博客基于Spring Data MongoDB实现，引入项目spring-boot-starter-data-mongodb实现MongoDB的分页，仅供参考
环境准备
- 开发环境
- JDK 1.8
- SpringBoot2.2.1
- Maven 3.2
- 开发工具
- IntelliJ IDEA
- smartGit
- Navicat15
Maven配置
新建一个SpringBoot下面，在pom配置文件里加上，dependencyManagement进行Springboot统一的版本控制
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-boot.version>2.2.1.RELEASE</spring-boot.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>加上mongoDB的starter配置，加上spring-boot-starter-data-mongodb封装好的starter
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>也可以加上PageHelper的配置，非必须
代码语言：javascript复制<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.10</version>
</dependency>MongoDB配置
有些版本启动可能会报错，所以可以先exclude数据库的自动配置，在Application类加上@SpringBootApplication(exclude= {DataSourceAutoConfiguration.class})
加上MongoDB的一些自定义配置
代码语言：javascript复制package com.example.mongodb.configuration;
import com.mongodb.ConnectionString;
import com.mongodb.MongoClientSettings;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import java.util.Collection;
import java.util.Collections;
@Configuration
@EnableMongoRepositories(basePackages = "com.example.mongodb.repository")
public class MongoConfiguration extends AbstractMongoClientConfiguration {
private static final String DB_NAME = "test";
private static final String IP = "127.0.0.1";
private static final String PORT = "27017";
@Override
public MongoClient mongoClient() {
ConnectionString str = new ConnectionString("mongodb://" IP ":" PORT "/" getDatabaseName());
MongoClientSettings mongoClientSettings = MongoClientSettings.builder()
.applyConnectionString(str)
.build();
return MongoClients.create(mongoClientSettings);
}
@Override
public MongoTemplate mongoTemplate() throws Exception {
return new MongoTemplate(mongoClient() , getDatabaseName());
}
@Override
protected String getDatabaseName() {
return DB_NAME;
}
@Override
protected Collection<String> getMappingBasePackages() {
return Collections.singleton("com.example.mongodb");
}
}代码实现
加上Document类，collection 对应数据库对应的文档
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
import lombok.experimental.SuperBuilder;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.MongoId;
import java.io.Serializable;
@Data
@SuperBuilder(toBuilder = true)
@AllArgsConstructor
@NoArgsConstructor
@ToString
@Document(collection = "user")
public class User implements Serializable {
@MongoId
private Long id;
private String name;
private Integer age;
private String email;
}加上接口实现MongoRepository<User, Long> ，一个User是对应的文档类，Long是对应的主键id
import com.example.mongodb.model.User;
import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.data.mongodb.repository.Query;
import org.springframework.stereotype.Repository;
import java.util.Optional;
@Repository
public interface UserRepository extends MongoRepository<User, Long> {
@Query("{ 'email' : ?0 }")
User findByEmail(String email);
@Query("{'_id' : ?0 }")
Optional<User> findById(Long id);
}业务实现类：基于ExampleMatcher 实现业务参数的加入，Pageable封装分页的参数
@Override
public org.springframework.data.domain.Page<User> mongoPageList(PageBean pageBean, User queryParam) {
User param = new User();
if (StrUtil.isNotBlank(queryParam.getName())) {
param.setName(queryParam.getName());
}
ExampleMatcher matcher = ExampleMatcher.matching()
.withMatcher("name", ExampleMatcher.GenericPropertyMatchers.contains());
Example<User> example = Example.of(param, matcher);
Sort sort = Sort.by(Sort.Direction.DESC, "_id");
Pageable pageable = PageRequest.of(pageBean.getPageIndex() - 1, pageBean.getPageRowNum(), sort);
org.springframework.data.domain.Page<User> page = userRepository.findAll(example, pageable);
return new PageImpl<User>(page.getContent() , pageable , page.getTotalElements());
}拓展
分页基于MongoRepository实现比较容易，不过发现index是从0开始的，返回的参数比较少，比如总页数，虽然也可以前端自己计算，不过为了统一规范，可以自己再根据需要进行封装
定义一个ResultBean，返回给前端
代码语言：javascript复制package com.example.mongodb.common.rest;
import lombok.Data;
import org.springframework.http.HttpStatus;
@Data
public class ResultBean<T> {
/**
* 状态
* */
private int status;
/**
* 描述
* */
private String desc;
/**
* 数据返回
* */
private T data;
public ResultBean(int status, String desc, T data) {
this.status = status;
this.desc = desc;
this.data = data;
}
public ResultBean(T data) {
this.status = HttpStatus.OK.value();
this.desc = "处理成功";
this.data = data;
}
public static <T> ResultBean<T> ok(T data) {
return new ResultBean(data);
}
public static <T> ResultBean<T> ok() {
return new ResultBean(null);
}
public static <T> ResultBean<T> badRequest(String desc,T data) {
return new ResultBean(HttpStatus.BAD_REQUEST.value(), desc, data);
}
public static <T> ResultBean<T> badRequest(String desc) {
return new ResultBean(HttpStatus.BAD_REQUEST.value(), desc, null);
}
public static <T> ResultBean serverError(String desc, T data){
return new ResultBean(HttpStatus.INTERNAL_SERVER_ERROR.value(),"服务器内部异常:" desc,data);
}
public static <T> ResultBean serverError(String desc){
return new ResultBean(HttpStatus.INTERNAL_SERVER_ERROR.value(),"服务器内部异常:" desc,null);
}
}分页的对象
代码语言：javascript复制package com.example.mongodb.common.page;
import lombok.Data;
@Data
public class PageObject {
// 当前页
private long pageIndex;
// 当前页数
private long pageRowNum;
// 总页数
private long totalPage;
// 总数量
private long totalRow;
}分页查询类
代码语言：javascript复制package com.example.mongodb.common.page;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.util.List;
import java.util.Optional;
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class PageBean {
// 当前页
private Integer pageIndex = 1;
// 一页的条数
private Integer pageRowNum = 10;
@JsonIgnore
private Page pages;
public void initPage() {
this.pages = PageHelper.startPage(pageIndex , pageRowNum);
}
public PageDataBean loadData(List dataList) {
return new PageDataBean(dataList , pages.getTotal() , pageIndex , pageRowNum);
}
public PageBean setPageBean(org.springframework.data.domain.Page page) {
PageBean pageBean = new PageBean();
pageBean.setPageRowNum(pageRowNum);
pageBean.setPageIndex(pageIndex);
Optional.ofNullable(page).ifPresent(e->{
Page<?> pageHelper = new Page<>();
pageHelper.setTotal(page.getTotalElements());
pageHelper.setPageNum(pageRowNum);
pageHelper.setPageSize(pageIndex);
pageBean.setPages(pageHelper);
});
return pageBean;
}
}分页数据返回类：
代码语言：javascript复制package com.example.mongodb.common.page;
import lombok.Data;
import java.util.ArrayList;
import java.util.List;
@Data
public class PageDataBean<T> {
private List<T> dataList = new ArrayList<>();
private PageObject pageObj = new PageObject();
public PageDataBean(List<T> dataList , Long totalRow , Integer pageIndex , Integer pageRowNum) {
this.dataList = dataList;
pageObj.setPageIndex(pageIndex);
pageObj.setPageRowNum(pageRowNum);
pageObj.setTotalRow(totalRow);
pageObj.setTotalPage(totalRow / pageRowNum (totalRow % pageRowNum == 0 ? 0 : 1));
}
}基于上面的封装类，Controller类进行调用：
代码语言：javascript复制@GetMapping(value = "/user/mongoPageList")
public ResultBean<PageDataBean<List<User>>> mongoPageList(PageBean pageBean , User param) {
Page<User> pageDataBean = userService.mongoPageList(pageBean, param);
pageBean = pageBean.setPageBean(pageDataBean);
return ResultBean.ok(pageBean.loadData(pageDataBean.getContent()));
}
