MyBatis分页查询助手

package com.tszr.mango.core.page;
import java.util.List;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.tszr.mango.common.utils.ReflectionUtils;
public class MybatisPageHelper {
public static final String findPage = "findPage";
/**
* 分页查询, 约定查询方法名为 “findPage”
*
* @param pageRequest 分页请求
* @param mapper Dao对象，MyBatis的 Mapper
* @param args 方法参数
* @return
*/
public static PageResult findPage(PageRequest pageRequest, Object mapper) {
return findPage(pageRequest, mapper, findPage);
}
/**
* 调用分页插件进行分页查询
*
* @param pageRequest 分页请求
* @param mapper Dao对象，MyBatis的 Mapper
* @param queryMethodName 要分页的查询方法名
* @param args 方法参数
* @return
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static PageResult findPage(PageRequest pageRequest, Object mapper, String queryMethodName, Object... args) {
// 设置分页参数
int pageNum = pageRequest.getPageNum();
int pageSize = pageRequest.getPageSize();
PageHelper.startPage(pageNum, pageSize);
// 利用反射调用查询方法
Object result = ReflectionUtils.invoke(mapper, queryMethodName, args);
return getPageResult(pageRequest, new PageInfo((List) result));
}
/**
* 将分页信息封装到统一的接口
*
* @param pageRequest
* @param page
* @return
*/
private static PageResult getPageResult(PageRequest pageRequest, PageInfo pageInfo) {
PageResult pageResult = new PageResult();
pageResult.setPageNum(pageInfo.getPageNum());
pageResult.setPageSize(pageInfo.getPageSize());
pageResult.setTotalSize(pageInfo.getTotal());
pageResult.setTotalPages(pageInfo.getPages());
pageResult.setContent(pageInfo.getList());
return pageResult;
}
}

package com.tszr.mango.core.page;
import java.util.HashMap;
import java.util.Map;
public class PageRequest {
/**
* 当前页码
*/
private int pageNum = 1;
/**
* 每页数量
*/
private int pageSize = 10;
/**
* 查询参数
*/
private Map params = new HashMap<>();

public int getPageNum() {
return pageNum;
}
public void setPageNum(int pageNum) {
this.pageNum = pageNum;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public Map getParams() {
return params;
}
public void setParams(Map params) {
this.params = params;
}
public Object getParam(String key) {
return getParams().get(key);
}
}

package com.tszr.mango.core.page;
import java.util.List;
public class PageResult {
/**
* 当前页码
*/
private int pageNum;
/**
* 每页数量
*/
private int pageSize;
/**
* 记录总数
*/
private long totalSize;
/**
* 页码总数
*/
private int totalPages;
/**
* 分页数据
*/
private List content;
public int getPageNum() {
return pageNum;
}
public void setPageNum(int pageNum) {
this.pageNum = pageNum;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public long getTotalSize() {
return totalSize;
}
public void setTotalSize(long totalSize) {
this.totalSize = totalSize;
}
public int getTotalPages() {
return totalPages;
}
public void setTotalPages(int totalPages) {
this.totalPages = totalPages;
}
public List getContent() {
return content;
}
public void setContent(List content) {
this.cOntent= content;
}
}