Spring 自定义注解分页实现

冷不防 2021-06-24 16:11 594阅读 0赞

1.首先自定义注解类

import java.lang.annotation.ElementType;
    import java.lang.annotation.Retention;
    import java.lang.annotation.RetentionPolicy;
    import java.lang.annotation.Target;
    
    @Target(ElementType.PARAMETER)
    @Retention(RetentionPolicy.RUNTIME)
    public @interface PageSolver {
    	
    }

2.分页PageInfo类

import java.util.List;
    
    public class Page<T>{
    	
    	//每页个数
    	private int pageSize = 15;
    	
    	//数据集合
    	private List<T> results ;
    	
    	//总数
    	private int total;
    	
    	//现在页码
    	private int page = 1;
    	
    	//分页查询开始位置
    	private int begin;
    	
    	//分页查询结束位置
    	private int end;
    	
    	private Object paras;
    	
    	private Object rows;
    	
    	public Page() {
    	}
    	
    	public Page(Integer begin,Integer pageSize){
    		this.begin = begin;
    		this.pageSize = pageSize;
    		this.end = this.begin + this.pageSize;
    		this.page = (int) Math.floor((this.begin * 1.0d) / this.pageSize) + 1;
    	}
    	
    	public int getPageSize() {
    		return pageSize;
    	}
    
    	public void setPageSize(int pageSize) {
    		this.pageSize = pageSize;
    		this.end = this.begin + this.pageSize;
    		if (this.begin != 0) {
    			this.page = (int) Math.floor((this.begin * 1.0d) / this.pageSize) + 1;
    		}
    	}
    	
    	public List<T> getResults() {
    		return results;
    	}
    
    	public void setResults(List<T> results) {
    		this.results = results;
    	}
    
    	public int getTotal() {
    		if (this.total == 0) {
    			return 1;
    		}
    		return this.total;
    	}
    
    	public void setTotal(int total) {
    		this.total = total;
    	}
    	
    	
    	public int getPage() {
    		return page;
    	}
    
    	public void setPage(int page) {
    		this.page = page;
    		this.begin = (this.page-1) * this.pageSize;
    		this.end = this.pageSize;
    	}
    
    	public int getBegin() {
    		return begin;
    	}
    
    	public void setBegin(int begin) {
    		this.begin = begin;
    		if (this.pageSize != 0) {
    			this.page = (int) Math.floor((this.begin * 1.0d) / this.pageSize) + 1;
    		}
    	}
    
    	public int getEnd() {
    		if(this.end==0)
    			this.end = this.pageSize;
    		return end;
    	}
    
    	public void setEnd(int end) {
    		this.end = end;
    	}
    
    	public Object getParas() {
    		return paras;
    	}
    
    	public void setParas(Object paras) {
    		this.paras = paras;
    	}
    
    	public Object getRows() {
    		return rows;
    	}
    
    	public void setRows(Object rows) {
    		this.rows = rows;
    	}
    	
    	
    }

3.在实现HandlerMethodArgumentResolver接口自定参数解析器

import javax.servlet.http.HttpServletRequest;
    
    import org.apache.commons.lang3.StringUtils;
    import org.springframework.core.MethodParameter;
    import org.springframework.web.bind.support.WebDataBinderFactory;
    import org.springframework.web.context.request.NativeWebRequest;
    import org.springframework.web.method.support.HandlerMethodArgumentResolver;
    import org.springframework.web.method.support.ModelAndViewContainer;
    
    import com.cn.annotation.PageSolver;
    import com.cn.base.page.Page;
    
    public class PageArgumentResolver implements HandlerMethodArgumentResolver{
    
    	@Override
    	public boolean supportsParameter(MethodParameter parameter) {
    		return null != parameter.getParameterAnnotation(PageSolver.class);
    	}
    
    	@Override
    	public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
    			NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
    		HttpServletRequest req = webRequest.getNativeRequest(HttpServletRequest.class);
    		Page<?> page = new Page<>();
    		// 页码
    		if (StringUtils.isNotBlank(req.getParameter("page"))) {
    			int current = Integer.parseInt(req.getParameter("page"));
    			page.setPage(current);
    		}
    		//页数
    		if(StringUtils.isNotBlank(req.getParameter("rows"))){
    			int length = Integer.parseInt(req.getParameter("rows"));
    			page.setPageSize(length);
    		}
    		return page;
    	}
    
    }

3.在springmvc.xml中添加

<mvc:annotation-driven>
    		
    		<mvc:argument-resolvers>
    	        <bean class="com.ymkj.credit.web.api.resolver.PageArgumentResolver"/>
    	    </mvc:argument-resolvers>
    	</mvc:annotation-driven>

4.在controller类中使用

@RequestMapping("/list")
    	@ResponseBody
    	public Page<User> list(Model model,@PageSolver Page<User> page,User user){
    		return userService.selectPageByColumn(page, user);
    	}

5.在service中实现

import com.cn.base.BaseService;
    import com.cn.hnust.pojo.User;
    
    public interface UserService extends BaseService<User>{
    
    }

6.在serviceimpl中实现

import org.springframework.stereotype.Service;
    
    import com.cn.base.BaseServiceImpl;
    import com.cn.hnust.pojo.User;
    import com.cn.hnust.service.UserService;
    
    @Service
    public class UserServiceImpl extends BaseServiceImpl<User> implements UserService {
    	
    }

7.在mapper中实现

import com.cn.base.BaseMapper;
    import com.cn.hnust.pojo.User;
    
    /**
     * UserMapper
     * @author system
     * @date 2018-03-30 16:30:38
     * @company test
     */
    public interface UserMapper extends BaseMapper<User> {
    }

8.在BaseService中实现

public interface BaseService<T> {
    
    	Page<T> selectPageByColumn(Page<T> page,T column);
    	
    	List<T> selectAllByColumn(T column);
    	 
    	T selectOneByColumn(T column);
    	
    	int selectCountByColumn(T column);
    	
    	int insertByColumn(T column);
    	
    	int deleteByKeys(String[] keys);
    	
    	int deleteByColumn(T column);
    	
    	int updateByColumn(T column);
    }

9.在BaseServiceimpl中实现

import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    
    import com.cn.base.page.Page;
    
    public class BaseServiceImpl<T> implements BaseService<T> {
    	
    	@Autowired
    	BaseMapper<T> baseMapper;
    
    	@Override
    	public Page<T> selectPageByColumn(Page<T> page, T column) {
    		int count = baseMapper.selectCountByColumn(column);
    		if(count > 0){
    			if (page == null){
    				page = new Page<T>();
    			}else{
    				if (page.getPage() * page.getPageSize() > count && Math.ceil(Double.valueOf(count) / Double.valueOf(page.getPageSize())) != page.getPage()) {
    					page.setPage(1);
    				}
    			}
    			page.setTotal(count);
    			page.setRows(baseMapper.selectPageByColumn(page, column));
    			page.setParas(column);
    			return page;
    		}
    		return null;
    	}
    
    	@Override
    	public List<T> selectAllByColumn(T column) {
    		return baseMapper.selectAllByColumn(column);
    	}
    
    	@Override
    	public T selectOneByColumn(T column) {
    		return baseMapper.selectOneByColumn(column);
    	}
    
    	@Override
    	public int selectCountByColumn(T column) {
    		return baseMapper.selectCountByColumn(column);
    	}
    
    	@Override
    	public int insertByColumn(T column) {
    		return baseMapper.insertByColumn(column);
    	}
    
    	@Override
    	public int deleteByKeys(String[] keys) {
    		return baseMapper.deleteByKeys(keys);
    	}
    
    	@Override
    	public int deleteByColumn(T column) {
    		return baseMapper.deleteByColumn(column);
    	}
    
    	@Override
    	public int updateByColumn(T column) {
    		return baseMapper.deleteByColumn(column);
    	}
    
    }

10.在Basemaper中实现

import java.util.List;
    
    import org.apache.ibatis.annotations.Param;
    
    import com.cn.base.page.Page;
    
    public interface BaseMapper<T>{
    
    	List<T> selectPageByColumn(@Param("page")Page<T> page, @Param("column")Object column);
    	
    	List<T> selectAllByColumn(@Param("column")T column);
    	 
    	T selectOneByColumn(@Param("column")T column);
    	
    	int selectCountByColumn(@Param("column")T column);
    	
    	int insertByColumn(T column);
    	
    	int deleteByKeys(String[] keys);
    	
    	int deleteByColumn(@Param("column")T column);
    	
    	int updateByColumn(T column);
    }

转载至链接:https://my.oschina.net/lisc2016/blog/2933819。