【框架】ssm的簡單例項-下篇
阿新 • • 發佈：2018-12-10
先看下專案結構圖：
先編寫控制器DictController和IndexController
@Controller
public class IndexController {
@RequestMapping(value = {"", "/index"})
public ModelAndView dicts() {
ModelAndView mv = new ModelAndView("index");
mv.addObject("now", new Date());
return mv;
}
}@Controller @RequestMapping("/dicts") public class DictController { @Autowired private DictService dictService; /** * 顯示字典資料列表 * * @param sysDict * @param offset * @param limit * @return */ @RequestMapping public ModelAndView dicts(SysDict sysDict, Integer offset, Integer limit) { ModelAndView mv = new ModelAndView("dicts"); List<SysDict> dicts = dictService.findBySysDict(sysDict, offset, limit); mv.addObject("dicts", dicts); int count = dictService.getCount(); mv.addObject("count", count); return mv; } /** * 新增或修改字典資訊頁面，使用 get 跳轉到頁面 * * @param id * @return */ @RequestMapping(value = "add", method = RequestMethod.GET) public ModelAndView add(Long id) { ModelAndView mv = new ModelAndView("dict_add"); SysDict sysDict; if(id == null){ //如果 id 不存在，就是新增資料，建立一個空物件即可 sysDict = new SysDict(); } else { //如果 id 存在，就是修改資料，把原有的資料查詢出來 sysDict = dictService.findById(id); } mv.addObject("model", sysDict); return mv; } /** * 新增或修改字典資訊，通過表單 post 提交資料 * * @param sysDict * @return */ @RequestMapping(value = "add", method = RequestMethod.POST) public ModelAndView save(SysDict sysDict) { ModelAndView mv = new ModelAndView(); try { dictService.saveOrUpdate(sysDict); mv.setViewName("redirect:/dicts"); } catch (Exception e){ mv.setViewName("dict_add"); mv.addObject("msg", e.getMessage()); mv.addObject("model", sysDict); } return mv; } /** * 通過 id 刪除字典資訊 * * @param id * @return */ @RequestMapping(value = "delete", method = RequestMethod.POST) @ResponseBody public ModelMap delete(@RequestParam Long id) { ModelMap modelMap = new ModelMap(); try { boolean success = dictService.deleteById(id); modelMap.put("success", success); } catch (Exception e) { modelMap.put("success", false); modelMap.put("msg", e.getMessage()); } return modelMap; } @RequestMapping(value = "count", method = RequestMethod.GET) public ModelMap getCount() { ModelMap modelMap = new ModelMap(); try { int count = dictService.getCount(); modelMap.put("count", count); } catch (Exception e) { modelMap.put("success", false); modelMap.put("msg", e.getMessage()); } return modelMap; } }
下面編寫service層
public interface DictService {
SysDict findById(Long id);
List<SysDict> findBySysDict(SysDict sysDict, Integer offset, Integer limit);
boolean saveOrUpdate(SysDict sysDict);
boolean deleteById(Long id);
int getCount();
}
@Service public class DictServiceImpl implements DictService { @Autowired private DictMapper dictMapper; @Override public SysDict findById(Long id2) { return dictMapper.selectByPrimaryKey(id2); } public List<SysDict> findBySysDict(SysDict sysDict, Integer offset, Integer limit) { RowBounds rowBounds = RowBounds.DEFAULT; if(offset != null && limit != null){ rowBounds = new RowBounds(offset, limit); } return dictMapper.selectBySysDict(sysDict, rowBounds); } @Override public boolean saveOrUpdate(SysDict sysDict) { if(sysDict.getId() == null){ return dictMapper.insert(sysDict) == 1; } else { return dictMapper.updateById(sysDict) == 1; } } @Override public boolean deleteById(Long id) { if(id == null){ throw new NullPointerException("id"); } return dictMapper.deleteById(id) == 1; } @Override public int getCount() { return dictMapper.getCount(); } }
下面編寫Model層
public class Memo {
private Long id;
private String info;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
}public class SysDict implements Serializable { private static final long serialVersionUID = 1L; private Long id; private String code; private String name; private String value; private List<Memo> memos; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getCode() { return code; } public void setCode(String code) { this.code = code; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getValue() { return value; } public void setValue(String value) { this.value = value; } public List<Memo> getMemos() { return memos; } public void setMemos(List<Memo> memos) { this.memos = memos; } }
下面配置MyBatis介面和對映檔案
public interface DictMapper {
/**
* 根據主鍵查詢
*
* @param id
* @return
*/
SysDict selectByPrimaryKey(Long id);
/**
* 條件查詢
*
* @param sysDict
* @return
*/
List<SysDict> selectBySysDict(SysDict sysDict, RowBounds rowBounds);
/**
* 新增
*
* @param sysDict
* @return
*/
int insert(SysDict sysDict);
/**
* 根據主鍵更新
*
* @param sysDict
* @return
*/
int updateById(SysDict sysDict);
/**
* 根據主鍵刪除
*
* @param id
* @return
*/
int deleteById(Long id);
int getCount();
}<?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="tk.mybatis.web.mapper.DictMapper">
<resultMap id="SysDictMap" type="SysDict">
<id property="id" column="id"/>
<result property="code" column="code"/>
<result property="name" column="name"/>
<result property="value" column="value"/>
<collection property="memos" resultMap="memo">
</collection>
</resultMap>
<resultMap id="memo" type="Memo">
<id property="id" column="mid"/>
<result property="info" column="info"/>
</resultMap>
<select id="getCount" resultType="Integer">
select count(*) from sys_dict;
</select>
<select id="selectByPrimaryKey" resultMap="SysDictMap">
select sys_dict.id, sys_dict.code, sys_dict.name, sys_dict.`value`,
memo.id mid,
memo.info info
from sys_dict inner join memo on sys_dict.id=memo.dictid where sys_dict.id=#{id}
</select>
<select id="selectBySysDict" resultMap="SysDictMap">
select * from sys_dict
<where>
<if test="id != null">
and id = #{id}
</if>
<if test="code != null and code != ''">
and code = #{code}
</if>
</where>
order by code, `value`
</select>
<!--useGeneratedKeys屬性使用jdbc的getGeneratedKeys()獲取主鍵 ，並賦值給keyProperty屬性指定的屬性名 -->
<insert id="insert" useGeneratedKeys="true" keyProperty="id">
insert into sys_dict(code, name, value)
values (#{code}, #{name}, #{value})
</insert>
<update id="updateById">
update sys_dict
set code = #{code},
name = #{name},
value = #{value}
where id = #{id}
</update>
<delete id="deleteById">
delete from sys_dict where id = #{id}
</delete>
</mapper>mybaits引數傳遞 #{abc}：MyBatis SQL中使用預編譯引數的一種方式，abc是傳入的引數名; （1）只有一個引數:此時mybatis並不關心引數叫什麼名字，就會直接把這個唯一的引數值拿來使用。 （2）多個引數 ： 1.可以使用#{0}，#{1}或者#{param1}，#{param1}，這種不直觀，且引數順序必須保證不變 2.可以把多個引數封裝成Map型別，key作為引數名 3.或者使用@param註解mybatis會自動把多個引數封裝成Map型別，省去手動構造Map引數過程。