springboot出现的错误

你好，我使用springboot，想显示mysql数据库的某条记录，结果出现了这样的错误、
Description:
Parameter 0 of method check in com.example.demo.dao.CangpinDao required a bean of type 'java.lang.String' that could not be found.
The injection point has the following annotations:
- @org.springframework.beans.factory.annotation.Autowired(required=true)
Action:
Consider defining a bean of type 'java.lang.String' in your configuration.
这是为什么啊？
附代码
这是Dao层的代码

package com.example.demo.dao;

import com.example.demo.bean.Cangpin;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository
public class CangpinDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;
    public void save(Cangpin cangpin){
        jdbcTemplate.update("insert into cangpin(xuhao,path2,sys,cangpinname,yuanjia,xianjia,num) values (?,?,?,?,?,?,?)",
                cangpin.getXuhao(),cangpin.getPath2(),cangpin.getSys(),cangpin.getCangpinname(),
                cangpin.getYuanjia(),cangpin.getXianjia(),cangpin.getNum());
    }
    @Autowired
    public void check(String a){
        jdbcTemplate.execute("select * from cangpin where xuhao = "+a);
    }
}

这是Bean的代码

package com.example.demo.bean;

public class Cangpin {
    private long xuhao;
    private String path2;

    public String getPath2() {
        return path2;
    }

    public void setPath2(String path2) {
        this.path2 = path2;
    }

    private String sys;

    public long getXuhao() {
        return xuhao;
    }

    public void setXuhao(long xuhao) {
        this.xuhao = xuhao;
    }



    public String getSys() {
        return sys;
    }

    public void setSys(String sys) {
        this.sys = sys;
    }

    public String getCangpinname() {
        return cangpinname;
    }

    public void setCangpinname(String cangpinname) {
        this.cangpinname = cangpinname;
    }

    public double getYuanjia() {
        return yuanjia;
    }

    public void setYuanjia(double yuanjia) {
        this.yuanjia = yuanjia;
    }

    public double getXianjia() {
        return xianjia;
    }

    public void setXianjia(double xianjia) {
        this.xianjia = xianjia;
    }

    public int getNum() {
        return num;
    }

    public void setNum(int num) {
        this.num = num;
    }

    private String cangpinname;
    private double yuanjia;
    private double xianjia;
    private int num;
}

这是Controller

```java
package com.example.demo.controller;

import com.example.demo.bean.Cangpin;
import com.example.demo.dao.CangpinDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;


@Controller
public class CangpinController {
    @Autowired
    private CangpinDao cpDao;
    @RequestMapping("/save")
    public String getCpDao() {
        Cangpin cp=new Cangpin();
        cp.setXuhao(1);
        cp.setPath2("da");
        cp.setSys("ss");
        cp.setCangpinname("银币");
        cp.setYuanjia(188.0);
        cp.setXianjia(18.0);
        cp.setNum(8844);
        cpDao.save(cp);
        return "插入成功";
    }
    @RequestMapping("/check")
    public void getCheck()
    {
        System.out.println("藏品");
    }
}

这是为什么呢？请回答。

CangpinDao中的check方法不要加@Autowired注解

如果你没有用过spring的话，这种不明意义的代码，就别写了

这里去掉