【Maven+SSM】如何通过Mybatis写一个中文查询请求及所遇到的问题

前言：

小白笔记。

正文：

一、接入Log4j。

可参考这篇文章。唯一不同的就是依赖jar包通过Maven的工具直接查找。

二、写一个根据中文名搜索的请求

1、写一个Service接口

package service;import java.util.List;import model.Book;public interface IBookService {Book getBookById(String bookId); List<Book> getBookByName(String bookName);}

2、上一篇文章，之前通过Mybatis自动生成工具生成的代码查询Id，本文基于上文添加。

2.1、dao层添加：

package dao;import java.util.List;import model.Book;public interface BookMapper {    int deleteByPrimaryKey(String id);    int insert(Book record);    int insertSelective(Book record);    Book selectByPrimaryKey(String id);    //添加搜姓名    List<Book> selectByName(String bookName);    int updateByPrimaryKeySelective(Book record);    int updateByPrimaryKeyWithBLOBs(Book record);    int updateByPrimaryKey(Book record);}

2.2、Mapping层（其中添加注释的两处地方为本次添加）

<?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="dao.BookMapper">  <resultMap id="BaseResultMap" type="model.Book">    <id column="id" jdbcType="VARCHAR" property="id" />    <result column="name" jdbcType="VARCHAR" property="name" />    <result column="chapter_name" jdbcType="VARCHAR" property="chapterName" />    <result column="owner" jdbcType="VARCHAR" property="owner" />  </resultMap>  <resultMap extends="BaseResultMap" id="ResultMapWithBLOBs" type="model.Book">    <result column="chapter_content" jdbcType="LONGVARCHAR" property="chapterContent" />  </resultMap>  <!--BookList： Book对应Model模块下Book类 -->  <resultMap id="BookList" type="model.Book">    <id column="id" jdbcType="VARCHAR" property="id" />    <result column="name" jdbcType="VARCHAR" property="name" />    <result column="chapter_name" jdbcType="VARCHAR" property="chapterName" />    <result column="owner" jdbcType="VARCHAR" property="owner" />    <result column="chapter_content" jdbcType="LONGVARCHAR" property="chapterContent" />  </resultMap>  <sql id="Base_Column_List">    id, name, chapter_name, owner  </sql>  <sql id="Blob_Column_List">    chapter_content  </sql>  <select id="selectByPrimaryKey" parameterType="java.lang.String" resultMap="ResultMapWithBLOBs">    select     <include refid="Base_Column_List" />    ,    <include refid="Blob_Column_List" />    from biquge    where id = #{id,jdbcType=VARCHAR}  </select>  <!-- 添加搜索姓名对应，其中BookList在上面 -->  <select id="selectByName" parameterType="java.lang.String" resultMap="BookList">  select id, name, chapter_name, owner , chapter_content from biquge where name =  #{name,jdbcType=VARCHAR};  </select>  <delete id="deleteByPrimaryKey" parameterType="java.lang.String">    delete from biquge    where id = #{id,jdbcType=VARCHAR}  </delete>  <insert id="insert" parameterType="model.Book">    insert into biquge (id, name, chapter_name,       owner, chapter_content)    values (#{id,jdbcType=VARCHAR}, #{name,jdbcType=VARCHAR}, #{chapterName,jdbcType=VARCHAR},       #{owner,jdbcType=VARCHAR}, #{chapterContent,jdbcType=LONGVARCHAR})  </insert>  <insert id="insertSelective" parameterType="model.Book">    insert into biquge    <trim prefix="(" suffix=")" suffixOverrides=",">      <if test="id != null">        id,      </if>      <if test="name != null">        name,      </if>      <if test="chapterName != null">        chapter_name,      </if>      <if test="owner != null">        owner,      </if>      <if test="chapterContent != null">        chapter_content,      </if>    </trim>    <trim prefix="values (" suffix=")" suffixOverrides=",">      <if test="id != null">        #{id,jdbcType=VARCHAR},      </if>      <if test="name != null">        #{name,jdbcType=VARCHAR},      </if>      <if test="chapterName != null">        #{chapterName,jdbcType=VARCHAR},      </if>      <if test="owner != null">        #{owner,jdbcType=VARCHAR},      </if>      <if test="chapterContent != null">        #{chapterContent,jdbcType=LONGVARCHAR},      </if>    </trim>  </insert>  <update id="updateByPrimaryKeySelective" parameterType="model.Book">    update biquge    <set>      <if test="name != null">        name = #{name,jdbcType=VARCHAR},      </if>      <if test="chapterName != null">        chapter_name = #{chapterName,jdbcType=VARCHAR},      </if>      <if test="owner != null">        owner = #{owner,jdbcType=VARCHAR},      </if>      <if test="chapterContent != null">        chapter_content = #{chapterContent,jdbcType=LONGVARCHAR},      </if>    </set>    where id = #{id,jdbcType=VARCHAR}  </update>  <update id="updateByPrimaryKeyWithBLOBs" parameterType="model.Book">    update biquge    set name = #{name,jdbcType=VARCHAR},      chapter_name = #{chapterName,jdbcType=VARCHAR},      owner = #{owner,jdbcType=VARCHAR},      chapter_content = #{chapterContent,jdbcType=LONGVARCHAR}    where id = #{id,jdbcType=VARCHAR}  </update>  <update id="updateByPrimaryKey" parameterType="model.Book">    update biquge    set name = #{name,jdbcType=VARCHAR},      chapter_name = #{chapterName,jdbcType=VARCHAR},      owner = #{owner,jdbcType=VARCHAR}    where id = #{id,jdbcType=VARCHAR}  </update></mapper>

3、写接口的实现，其中getBookByName方法中调用上面添加的查询

package service;import java.util.List;import javax.annotation.Resource;import org.springframework.stereotype.Service;import dao.BookMapper;import model.Book;@Service("userService")public class BookServiceImpl implements IBookService{@Resourceprivate BookMapper bookDao;public Book getBookById(String bookId) {// TODO Auto-generated method stubreturn this.bookDao.selectByPrimaryKey(bookId);}public List<Book> getBookByName(String bookName) {return this.bookDao.selectByName(bookName);}}

4、写一个Controller

@Controllerpublic class HelloController {private static Logger log = LoggerFactory.getLogger(HelloController.class);@Resource  private IBookService iBookService;@RequestMapping(value="d.do",produces="text/html;charset=UTF-8")public @ResponseBody String viewBook() {List<Book> bl = iBookService.getBookByName("大明春色");System.out.println(bl.toString());//添加error日志log.error("----log-----");return "你好";}}

问题一、根据日志，发现查询出来结果为0条。原因是搜索的中文utf-8。所以在数据库的连接配置文件上添加如下：

driver=com.mysql.jdbc.Driverurl=jdbc:mysql://localhost:3306/ebook?useUnicode=true&characterEncoding=UTF-8username=rootpassword=haibo1118initialSize=5

然后就能查出很多条结果了。

5、改造成一个能修改参数的Get请求

觉得我这个固定的搜索名字不像一个请求？那么我就改改Controller即可。get请求如下：http://localhost:8080/mvnStudy01/e.do?name=大明春色

package controller;import java.util.List;import javax.annotation.Resource;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.ResponseBody;import model.Book;import service.IBookService;@Controllerpublic class HelloController {private static Logger log = LoggerFactory.getLogger(HelloController.class);@Resource  private IBookService iBookService;@RequestMapping(value="d.do",produces="text/html;charset=UTF-8")public @ResponseBody String viewBook() {List<Book> bl = iBookService.getBookByName("大明春色");System.out.println(bl.toString());//添加error日志log.error("----log-----");return "你好";}@RequestMapping(value="e.do",produces="text/html;charset=UTF-8")public @ResponseBody String viewBookByName(@RequestParam(name="name",defaultValue="大明春色")String name) {List<Book> bl = iBookService.getBookByName(name);System.out.println(bl.toString());//添加error日志log.error("----log-----");return "你好";}}

6、Post请求

package controller;import java.util.List;import javax.annotation.Resource;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.ResponseBody;import model.Book;import service.IBookService;@Controllerpublic class HelloController {private static Logger log = LoggerFactory.getLogger(HelloController.class);@Resource  private IBookService iBookService;@RequestMapping(value="d.do",produces="text/html;charset=UTF-8")public @ResponseBody String viewBook() {List<Book> bl = iBookService.getBookByName("大明春色");System.out.println(bl.toString());//添加error日志log.error("----log-----");return "你好";}@RequestMapping(value="e.do",produces="text/html;charset=UTF-8")public @ResponseBody String viewBookByName(@RequestParam(name="name",defaultValue="大明春色")String name) {List<Book> bl = iBookService.getBookByName(name);System.out.println(bl.toString());//添加error日志log.error("----log-----");return "你好";}//Post请求@RequestMapping(value="f.do",method=RequestMethod.POST,produces="text/html;charset=UTF-8")public @ResponseBody String postBookByName(String name) {System.out.println(name.toString());List<Book> bl = iBookService.getBookByName(name);//添加error日志log.error("----log-----"+bl.toString());return "你好";}}

问题二、Post请求时name原本是中文，变成了接收到的是乱码

大明春色

解决方案：在web.xml中添加如下代码：

<!-- 配置springMVC编码过滤器 -->  <filter>  <filter-name>CharacterEncodingFilter</filter-name>  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>  <!-- 设置过滤器中的属性值 -->  <init-param>  <param-name>encoding</param-name>  <param-value>UTF-8</param-value>  </init-param>  <!-- 启动过滤器 -->  <init-param>  <param-name>forceEncoding</param-name>  <param-value>true</param-value>  </init-param>  </filter>  <!-- 过滤所有请求 -->  <filter-mapping>  <filter-name>CharacterEncodingFilter</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>

如果添加之后没效果，重启服务即可看到Post请求的中文乱码问题被解决。

7、Rest风格的get请求改造。

Controller代码如下：即通过PathVariable绑定入参和URL

//get请求,Rest风格@RequestMapping(value="/view/{name}",method=RequestMethod.GET,produces="text/html;charset=UTF-8")public @ResponseBody String restBookByName(@PathVariable("name")String name) {List<Book> bl = iBookService.getBookByName(name);System.out.println(bl.toString());//添加error日志log.error("----log-----");return "你好";}

请求连接如下：http://localhost:8080/mvnStudy01/view/大明春色

这样就可以访问get请求了，当然比之前更加优雅。

PS：此处我对之前web.xml修改了过滤，改成了对所有请求过滤/,web.xml其中的修改部分如下

<servlet-mapping><servlet-name>springmvc</servlet-name><url-pattern>/</url-pattern></servlet-mapping>

8、HttpServlet+SpringMVC风格结合：

我就是喜欢这种古朴的风格，那怎么写？

//古老风格HttpServlet与SpringMVC的结合@RequestMapping(value="/view2",method=RequestMethod.GET,produces="text/html;charset=UTF-8")public @ResponseBody String httpServletBookByName(HttpServletRequest request) {List<Book> bl = iBookService.getBookByName(request.getParameter("name"));System.out.println(bl.toString());//添加error日志log.error("----log-----");return "你好：古老风格HttpServlet与SpringMVC的结合";}

请求如下：

http://localhost:8080/mvnStudy01/view2?name=大明春色

完美！到此为止。