Spring Boot 中各种分页查询方式完整示例

在 Spring Boot 中，实现分页查询有多种方式，下面我将介绍几种常见的分页实现方法，包括 Spring Data JPA 分页、MyBatis 分页、手动分页等。

1. Spring Data JPA 分页

这是最简单和常用的分页方式，Spring Data JPA 内置了分页支持。

1.1 基本实现

首先，添加依赖：

XML 复制代码

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>com.mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
</dependency>

实体类：

java 复制代码

@Entity
@Table(name = "users")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private String email;
    // getters, setters, constructors...
}

Repository 接口：

java 复制代码

public interface UserRepository extends JpaRepository<User, Long> {
    Page<User> findByNameContaining(String name, Pageable pageable);
}

Service 层：

java 复制代码

@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;
    
    public Page<User> getUsersByName(String name, int page, int size) {
        Pageable pageable = PageRequest.of(page, size, Sort.by("name").ascending());
        return userRepository.findByNameContaining(name, pageable);
    }
}

Controller 层：

java 复制代码

@RestController
@RequestMapping("/api/users")
public class UserController {
    @Autowired
    private UserService userService;
    
    @GetMapping
    public ResponseEntity<Page<User>> getUsers(
            @RequestParam(required = false) String name,
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "10") int size) {
        return ResponseEntity.ok(userService.getUsersByName(name, page, size));
    }
}

1.2 自定义返回结果

有时我们需要自定义返回数据结构：

java 复制代码

public class PageResult<T> {
    private List<T> content;
    private int page;
    private int size;
    private long totalElements;
    private int totalPages;
    // getters, setters...
    
    public static <T> PageResult<T> fromPage(Page<T> page) {
        PageResult<T> result = new PageResult<>();
        result.setContent(page.getContent());
        result.setPage(page.getNumber());
        result.setSize(page.getSize());
        result.setTotalElements(page.getTotalElements());
        result.setTotalPages(page.getTotalPages());
        return result;
    }
}

然后在 Controller 中使用：

java 复制代码

@GetMapping("/custom")
public ResponseEntity<PageResult<User>> getUsersCustom(
        @RequestParam(required = false) String name,
        @RequestParam(defaultValue = "0") int page,
        @RequestParam(defaultValue = "10") int size) {
    Page<User> userPage = userService.getUsersByName(name, page, size);
    return ResponseEntity.ok(PageResult.fromPage(userPage));
}

2. MyBatis 分页

2.1 使用 PageHelper

添加依赖：

XML 复制代码

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>最新版本</version>
</dependency>

Mapper 接口：

java 复制代码

@Mapper
public interface UserMapper {
    List<User> findByName(@Param("name") String name);
}

Service 层：

java 复制代码

@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
    
    public PageInfo<User> getUsersByName(String name, int page, int size) {
        PageHelper.startPage(page, size);
        List<User> users = userMapper.findByName(name);
        return new PageInfo<>(users);
    }
}

Controller 层：

java 复制代码

@GetMapping("/mybatis")
public ResponseEntity<PageInfo<User>> getUsersMybatis(
        @RequestParam(required = false) String name,
        @RequestParam(defaultValue = "0") int page,
        @RequestParam(defaultValue = "10") int size) {
    return ResponseEntity.ok(userService.getUsersByName(name, page, size));
}

2.2 MyBatis-Plus 分页

添加依赖：

XML 复制代码

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>最新版本</version>
</dependency>

配置分页插件：

java 复制代码

@Configuration
public class MybatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

Mapper 接口：

java 复制代码

public interface UserMapper extends BaseMapper<User> {
    // 继承基本方法
}

Service 层：

java 复制代码

@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
    
    public IPage<User> getUsersByName(String name, int page, int size) {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.like("name", name);
        return userMapper.selectPage(new Page<>(page, size), wrapper);
    }
}

Controller 层：

java 复制代码

@GetMapping("/mybatis-plus")
public ResponseEntity<IPage<User>> getUsersMybatisPlus(
        @RequestParam(required = false) String name,
        @RequestParam(defaultValue = "0") int page,
        @RequestParam(defaultValue = "10") int size) {
    return ResponseEntity.ok(userService.getUsersByName(name, page, size));
}

3. 手动分页

当数据量不大或需要特殊处理时，可以使用手动分页：

java 复制代码

@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;
    
    public List<User> getUsersManually(String name, int page, int size) {
        List<User> allUsers = userRepository.findByNameContaining(name);
        
        int fromIndex = page * size;
        if (fromIndex >= allUsers.size()) {
            return Collections.emptyList();
        }
        
        int toIndex = Math.min(fromIndex + size, allUsers.size());
        return allUsers.subList(fromIndex, toIndex);
    }
    
    public Map<String, Object> getUsersWithTotal(String name, int page, int size) {
        List<User> allUsers = userRepository.findByNameContaining(name);
        List<User> pageContent = getUsersManually(name, page, size);
        
        Map<String, Object> result = new HashMap<>();
        result.put("content", pageContent);
        result.put("currentPage", page);
        result.put("pageSize", size);
        result.put("totalElements", allUsers.size());
        result.put("totalPages", (int) Math.ceil((double) allUsers.size() / size));
        
        return result;
    }
}

Controller 层：

java 复制代码

@GetMapping("/manual")
public ResponseEntity<Map<String, Object>> getUsersManual(
        @RequestParam(required = false) String name,
        @RequestParam(defaultValue = "0") int page,
        @RequestParam(defaultValue = "10") int size) {
    return ResponseEntity.ok(userService.getUsersWithTotal(name, page, size));
}

4. WebMvc 分页参数自动绑定

可以创建一个分页参数类来自动绑定分页参数：

java 复制代码

public class PageParam {
    @Min(0)
    private int page = 0;
    
    @Min(1)
    @Max(100)
    private int size = 10;
    
    private String sort = "id,asc"; // 格式: field,direction
    
    // getters, setters...
    
    public Pageable toPageable() {
        String[] parts = sort.split(",");
        if (parts.length == 2) {
            return PageRequest.of(page, size, 
                Sort.by(Sort.Direction.fromString(parts[1]), parts[0]));
        }
        return PageRequest.of(page, size);
    }
}

Controller 使用：

java 复制代码

@GetMapping("/auto-page")
public ResponseEntity<Page<User>> getUsersAutoPage(
        @RequestParam(required = false) String name,
        PageParam pageParam) {
    return ResponseEntity.ok(userRepository.findByNameContaining(name, pageParam.toPageable()));
}

5. 响应式分页 (WebFlux)

如果使用 Spring WebFlux:

添加依赖：

XML 复制代码

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>

Repository:

java 复制代码

public interface ReactiveUserRepository extends ReactiveMongoRepository<User, String> {
    Flux<User> findByNameContaining(String name, Pageable pageable);
}

Service:

java 复制代码

@Service
public class ReactiveUserService {
    @Autowired
    private ReactiveUserRepository userRepository;
    
    public Mono<Page<User>> getUsers(String name, int page, int size) {
        Pageable pageable = PageRequest.of(page, size);
        Flux<User> userFlux = userRepository.findByNameContaining(name, pageable);
        Mono<Long> countMono = userRepository.countByNameContaining(name);
        
        return Mono.zip(userFlux.collectList(), countMono)
            .map(tuple -> new PageImpl<>(tuple.getT1(), pageable, tuple.getT2()));
    }
}

Controller:

java 复制代码

@RestController
@RequestMapping("/api/reactive/users")
public class ReactiveUserController {
    @Autowired
    private ReactiveUserService userService;
    
    @GetMapping
    public Mono<ResponseEntity<Page<User>>> getUsers(
            @RequestParam(required = false) String name,
            @RequestParam(defaultValue = "0") int page,
            @RequestParam(defaultValue = "10") int size) {
        return userService.getUsers(name, page, size)
            .map(ResponseEntity::ok)
            .defaultIfEmpty(ResponseEntity.notFound().build());
    }
}

总结

Spring Data JPA 分页：最简单，适合大多数 CRUD 应用
MyBatis 分页：
- PageHelper：简单易用
- MyBatis-Plus：功能更强大
手动分页：灵活，适合特殊需求
自动绑定分页参数：提高代码整洁度
响应式分页：适合响应式应用

根据项目需求和技术栈选择合适的分页方式。对于大多数 Spring Boot 项目，Spring Data JPA 或 MyBatis-Plus 的分页功能已经足够强大且易于使用。