本文参考自: https://blog.csdn.net/chenyezhou1/article/details/71122570
(1)基础的查询操作,因为jdbcTemplate不像mybatis那种有对应的映射关系,因此操作实体,需要手写函数
class UserRowMapper implements RowMapper<User> {
public User mapRow(ResultSet rs, int rowNum) throws SQLException {
User user = new User();
user.setId(rs.getInt("id"));
user.setName(rs.getString("name"));
user.setGender(rs.getString("gender"));
return user;
}
}
(2)如果想直接返回实体,可以配置RowMapper通用类
public class GenericMapper implements RowMapper<Map<String, String>> {
@Override
public Map<String, String> mapRow(ResultSet rs, int index) throws SQLException {
ResultSetMetaData metaData = rs.getMetaData();
int columnCount = metaData.getColumnCount();
Map<String, String> map = new HashMap<>(8);
for (int i = 1; i <= columnCount; i++) {
// System.out.println("columnName:" + metaData.getColumnName(i)); 与下方的返回值相同
// System.out.println("columnLabel:" + metaData.getColumnLabel(i));
String columnName = metaData.getColumnName(i);
String value = rs.getString(columnName);
if (value == null || " ".equals(value)) {
//这里是将为null或者" "的列数据赋值为"",可以按不同的需求进行更改
value = "";
} else {
value = rs.getString(columnName);
}
map.put(columnName, value);
}
return map;
}
}
用的时候直接调用即可,这里我为了方便直接写在了controller层
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.cpicdg.dc.datacauser.util.GenericMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* @program: datacauser
* @description: 数据控制层,目前就是单纯的数据给出接口,逻辑直接写在controller层
* @author: zyy
* @create: 2020-03-31 10:56
**/
@RestController
@RequestMapping("/outData")
public class DataController {
private Logger logger = LoggerFactory.getLogger(this.getClass());
private final JdbcTemplate jdbcTemplate;
@Autowired
public DataController(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
@GetMapping
public String getData() {
String sql = "select * from sys.sys_config;";
List<Map<String, String>> query = jdbcTemplate.query(sql, new GenericMapper());
logger.info(JSON.toJSONString(query));
return JSONObject.toJSONString(query);
}
}