项目实战：新增@Controller和@Service@Repository@Autowire四个注解

1、@Controller

package com.csdn.mymvc.annotation;
import java.lang.annotation.*;
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface Controller {
}

2、@Service

package com.csdn.mymvc.annotation;
import java.lang.annotation.*;
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface Service {
}

3、@Repository

package com.csdn.mymvc.annotation;
import java.lang.annotation.*;
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface Repository {
}

4、@Autowire

package com.csdn.mymvc.annotation;
import java.lang.annotation.*;
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface Autowire {
}

 1、FruitController

package com.csdn.fruit.servlet;
import com.csdn.fruit.dto.PageInfo;
import com.csdn.fruit.dto.PageQueryParam;
import com.csdn.fruit.dto.Result;
import com.csdn.fruit.pojo.Fruit;
import com.csdn.fruit.service.FruitService;
import com.csdn.fruit.util.RequestUtil;
import com.csdn.fruit.util.ResponseUtil;
import com.csdn.mymvc.annotation.*;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
@Controller
@RequestMapping("/fruit")
public class FruitController {@Autowireprivate FruitService fruitService;@GetMapping("/index")protected void index(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Integer pageNo = 1;String pageNoStr = req.getParameter("pageNo");if (pageNoStr != null && !"".equals(pageNoStr)) {pageNo = Integer.parseInt(pageNoStr);}String keyword = "";String keywordStr = req.getParameter("keyword");if (keywordStr != null) {keyword = keywordStr;}PageQueryParam pageQueryParam = new PageQueryParam(pageNo, 5, keyword);PageInfo<Fruit> pageInfo = fruitService.getFruitPageInfo(pageQueryParam);Result result = Result.OK(pageInfo);ResponseUtil.print(resp, result);}@PostMapping("/add")protected void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Fruit fruit = (Fruit) RequestUtil.readObject(req, Fruit.class);fruitService.addFruit(fruit);ResponseUtil.print(resp, Result.OK());}@GetMapping("/del")protected void del(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Integer fid = Integer.parseInt(req.getParameter("fid"));fruitService.delFruit(fid);ResponseUtil.print(resp, Result.OK());}@GetMapping("/edit")protected void edit(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Integer fid = Integer.parseInt(req.getParameter("fid"));Fruit fruit = fruitService.getFruitById(fid);ResponseUtil.print(resp, Result.OK(fruit));}@GetMapping("/getFname")public void getFname(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String fname = req.getParameter("fname");Fruit fruit = fruitService.getFruitByFname(fname);ResponseUtil.print(resp, fruit == null ? Result.OK() : Result.Fail());}@PostMapping("/update")protected void update(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {Fruit fruit = (Fruit) RequestUtil.readObject(req, Fruit.class);fruitService.updateFruit(fruit);ResponseUtil.print(resp, Result.OK());}
}

2、FruitServiceImpl

package com.csdn.fruit.service.impl;
import com.csdn.fruit.dao.FruitDao;
import com.csdn.fruit.dto.PageInfo;
import com.csdn.fruit.dto.PageQueryParam;
import com.csdn.fruit.pojo.Fruit;
import com.csdn.fruit.service.FruitService;
import com.csdn.mymvc.annotation.Autowire;
import com.csdn.mymvc.annotation.Service;
import java.util.List;
@Service
public class FruitServiceImpl implements FruitService {@Autowireprivate FruitDao fruitDao ;@Overridepublic PageInfo<Fruit> getFruitPageInfo(PageQueryParam pageQueryParam) {Integer pageNo = pageQueryParam.getPageNo();Integer pageSize = pageQueryParam.getPageSize();String keyword = pageQueryParam.getKeyword();List<Fruit> fruitList = fruitDao.getFruitList(pageNo, pageSize, keyword);Integer recordCount = fruitDao.getRecordCount(pageQueryParam.getKeyword());PageInfo<Fruit> fruitPageInfo = new PageInfo<>(fruitList, pageNo, recordCount);return fruitPageInfo;}@Overridepublic void addFruit(Fruit fruit) {if (fruitDao.getFruitByFname(fruit.getFname()) == null) {fruitDao.addFruit(fruit);}}@Overridepublic void updateFruit(Fruit fruit) {fruitDao.updateFruit(fruit);}@Overridepublic void delFruit(Integer fid) {fruitDao.delFruitByFid(fid);}@Overridepublic Fruit getFruitById(Integer fid) {return fruitDao.getFruitByFid(fid);}@Overridepublic Fruit getFruitByFname(String fname) {return fruitDao.getFruitByFname(fname);}
}

3、FruitDaoImpl

package com.csdn.fruit.dao.impl;
import com.csdn.fruit.dao.FruitDao;
import com.csdn.fruit.pojo.Fruit;
import com.csdn.mymvc.annotation.Repository;
import com.csdn.mymvc.dao.BaseDao;
import java.util.List;
@Repository
public class FruitDaoImpl extends BaseDao<Fruit> implements FruitDao {@Overridepublic void addFruit(Fruit fruit) {String sql = "insert into t_fruit values (0,?,?,?,?)";super.executeUpdate(sql, fruit.getFname(), fruit.getPrice(), fruit.getFcount(), fruit.getRemark());}@Overridepublic void delFruit(String fname) {String sql = "delete from t_fruit where fname=?";super.executeUpdate(sql, fname);}//通过 fid 删除水果库存记录@Overridepublic void delFruitByFid(Integer fid) {super.executeUpdate("delete from t_fruit where fid = ? ", fid);}//通过 fid 可以修改所有的属性值@Overridepublic void updateFruit(Fruit fruit) {String sql = "update  t_fruit set fname=?,price=?,fcount=?,remark=? where fid = ?";super.executeUpdate(sql, fruit.getFname(), fruit.getPrice(), fruit.getFcount(), fruit.getRemark(), fruit.getFid());}@Overridepublic List<Fruit> getFruitList() {return super.executeQuery("select * from t_fruit");}@Overridepublic List<Fruit> getFruitList(Integer pageNo, Integer pageSize) {return super.executeQuery("select * from t_fruit limit ?,?", (pageNo - 1) * pageSize, pageSize);}@Overridepublic List<Fruit> getFruitList(Integer pageNo, Integer pageSize, String keyword) {return super.executeQuery("select * from t_fruit where fname like ? or remark like?  limit ?,?", "%" + keyword + "%", "%" + keyword + "%", (pageNo - 1) * pageSize, pageSize);}@Overridepublic Fruit getFruitByFname(String fname) {return load("select * from t_fruit where fname = ?", fname);}@Overridepublic Fruit getFruitByFid(Integer fid) {return load("select * from t_fruit where fid=?", fid);}@Overridepublic Integer getRecordCount() {String sql = "select count(*) from t_fruit";return ((Long) executeComplexQuery(sql).get(0)[0]).intValue();}@Overridepublic Integer getRecordCount(String keyword) {String sql = "select count(*) from t_fruit where fname like ? or remark like ? ";return ((Long) executeComplexQuery(sql, "%" + keyword + "%", "%" + keyword + "%").get(0)[0]).intValue();}
}