多字段模糊查询书籍持久层实现

要进行模糊分页查询书籍表books如下：

首先，先得要一个用于放分页相关信息的实体类
1.在codewen.bookcool.entity下创建一个Page类(注意这个Page类持久层没啥作用，主要是业务逻辑层会将分页的总数据数totaldata，总页数totalpage，页面大小pagesize,当前页面currentpage,页码currentpageNum,接收分页查询的一页结果集和pageLists封装到Page类中然后返给上层的servlet，servlet再做出响应将Page里的数据传给jsp，jsp将数据取出并显示)

import java.util.List;

/**
 * 用于分页的实体类
 * @author codewen
 *
 */
public class Page<T> {
	
	private int totaldata;//总数据数
	private int pagesize;//页面大小
	private int totalpage;//总页数
	private int currentpage;//当前页面
	private int currentpageNum;//当前页码
	private List<T> pageLists;//接收分页查询的一页结果集
	
	public Page() {
		
	}
	
	public Page(int totaldata, int pagesize, int totalpage, int currentpage,
			int currentpageNum, List<T> pageLists) {
		this.totaldata = totaldata;
		this.pagesize = pagesize;
		this.totalpage = totalpage;
		this.currentpage = currentpage;
		this.currentpageNum = currentpageNum;
		this.pageLists = pageLists;
	}

	public List<T> getPageLists() {
		return pageLists;
	}

	public void setPageLists(List<T> pageLists) {
		this.pageLists = pageLists;
	}

	public int getTotaldata() {
		return totaldata;
	}
	public void setTotaldata(int totaldata) {
		this.totaldata = totaldata;
	}
	public int getPagesize() {
		return pagesize;
	}
	public void setPagesize(int pagesize) {
		this.pagesize = pagesize;
	}
	public int getTotalpage() {
		return totalpage;
	}
	public void setTotalpage(int totalpage) {
		this.totalpage = totalpage;
	}
	public int getCurrentpage() {
		return currentpage;
	}
	public void setCurrentpage(int currentpage) {
		this.currentpage = currentpage;
	}
	public int getCurrentpageNum() {
		return currentpageNum;
	}
	public void setCurrentpageNum(int currentpageNum) {
		this.currentpageNum = currentpageNum;
	}

	@Override
	public String toString() {
		return "Page [totaldata=" + totaldata + ", pagesize=" + pagesize
				+ ", totalpage=" + totalpage + ", currentpage=" + currentpage
				+ ", currentpageNum=" + currentpageNum + ", pageLists="
				+ pageLists + "]";
	}
}

2.在codewen.bookcool.mapper接口包中创建一个接口BookMapper
并在BookMapper接口中加queryTotalBook和queryBookByPage方法

import java.util.List;
import java.util.Map;

import org.apache.ibatis.annotations.Param;

import codewen.bookcool.entity.Book;

public interface BookMapper {
	//查询书籍数
	public int queryTotalBook(@Param("parameterMap")Map<String, String[]> parameterMap);
	
	//查询一页书籍
	public List<Book> queryBookByPage(@Param("currentpage")int currentpage
			,@Param("pagesize")int pagesize
			,@Param("parameterMap")Map<String, String[]> parameterMap);
}

3.在conf文件夹下的codewen,bookcool.mapper包下新建BookMapper.xml文件
并在BookMapper.xml加上刚刚那两个方法的SQL语句
具体SQL语句是：SELECT * FROM books WHERE CONCAT(bname,bauthor,bcategory) LIKE '%?%' LIMIT ?,?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"  
"http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 
<mapper namespace="codewen.bookcool.mapper.BookMapper">
    <!-- 可重用的查询所有书的sql -->
    <sql id="queryAllBook">
        select * from books
    </sql>
    <!-- 可重用的通过书籍参数查询sql -->
    <sql id="queryBookCondition">
        <!-- 先判断Map集合是否为空然后再判断value是否为空 -->
        <if test="parameterMap !=null ">
            <if test="parameterMap.fparam !=null and parameterMap.fparam !='' ">
                <bind name="binidfparam" value=" '%'+parameterMap.fparam[0]+'%' "/>
                <where>
                    concat(bname,bauthor,bcategory) like #{binidfparam}
                </where>
            </if>
        </if>
    </sql>
    
    <!-- //查询书籍数
    public int queryTotalBook(@Param("parameterMap")Map<String, String[]> parameterMap); -->
    <select id="queryTotalBook" resultType="int">
        select count(1) from books
        <include refid="queryBookCondition"/>
    </select>
    
    <!-- //查询一页书籍
    public List<Book> queryBookByPage(@Param("currentpage")int currentpage
            ,@Param("pagesize")int pagesize
            ,@Param("parameterMap")Map<String, String[]> parameterMap); -->
    <select id="queryBookByPage" resultType="codewen.bookcool.entity.Book">
        <include refid="queryAllBook"/>
        <include refid="queryBookCondition"/>
        limit #{currentpage},#{pagesize}
    </select>
</mapper>

4.到test包的新建BookTest测试类并在其中测试即可（只是测试语句啥的有没有写错）

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import codewen.bookcool.entity.Book;
import codewen.bookcool.mapper.BookMapper;
import codewen.bookcool.until.MyBatisUtil;

public class BookTest {
@Test
	public void test5() {
		SqlSession session = MyBatisUtil.getSession();
		BookMapper mapper = session.getMapper(BookMapper.class);
		Map<String, String[]> parameterMap = new HashMap<>();
		String[] fparam = {"天"};
		parameterMap.put("fparam", fparam);
		List<Book> books = mapper.queryBookByPage(0, 10, parameterMap);
		MyBatisUtil.closeSession();
		for (Book book : books) {
			System.out.println(book);
		}
	}	
}

结果如下：