Java org.apache.commons.dbcp.DelegatingPreparedStatement不能强制转换为com.mysql.jdbc.PreparedStatement

我正在尝试使用prepared语句查询数据库，但出现错误： org.apache.commons.dbcp.DelegatingPreparedStatement不能强制转换为com.mysql.jdbc.PreparedStatement

导入

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.PreparedStatementCreator;
import org.springframework.jdbc.core.ResultSetExtractor;
import org.springframework.jdbc.core.simple.ParameterizedRowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.jdbc.support.GeneratedKeyHolder;
import org.springframework.jdbc.support.KeyHolder;
import org.springframework.stereotype.Repository;


import com.mysql.jdbc.PreparedStatement;
import com.mysql.jdbc.Statement;

JDBC

public List<Crime> getCrimeList(Crime crime) {
        String where_clause = "";

        final List<Object> args = new ArrayList<Object>();
        final StringBuilder whereClause = new StringBuilder();


        if (crime.getCrimeDate()!= null){
             whereClause.append(" and crime.crimeDate = ?");
             args.add(crime.getCrimeDate());

        }

        if(crime.getCrimeDetails() != null){
            whereClause.append(" and crime.crimeDetails = ?");
             args.add(crime.getCrimeDetails());

        }

        ..............

        logger.debug("In getCrimeList()");
        final String sql = "select crime.*, "+
                     "criminalSocialSecurityNumber,criminal.fName as criminalFName,criminal.lName as criminalLName,"+
                     "criminal.photo as criminalPhoto,criminal.dob as criminalDob,victimSocialSecurityNumber,"+
                     "victim.fName as victimFName,victim.lName as victimLName,victim.photo as victimPhoto, victim.dob as victimDob "+ 
                     "from tblcrimes crime "+
                     "left join tblcriminalcrime on crime.crimeRecNo = tblcriminalcrime.crimeRecNo "+
                     "left join tblvictimcrime on crime.crimeRecNo = tblvictimcrime.crimeRecNo "+
                     "inner join tblcitizens criminal on criminal.socialSecurityNumber = tblcriminalcrime.criminalSocialSecurityNumber "+
                     "inner join tblcitizens victim on victim.socialSecurityNumber = tblvictimcrime.victimSocialSecurityNumber ";

        logger.debug("Executing getCrimeList String "+sql);



        List<Crime> crimeList = getJdbcTemplate().query(new PreparedStatementCreator(){

        public java.sql.PreparedStatement createPreparedStatement(
                java.sql.Connection connection) throws SQLException {

            PreparedStatement ps =(PreparedStatement) connection.prepareStatement(sql + whereClause);
            int i = 1;
            for (Object arg : args) {
                ps.setObject(i, arg);
                i++;
            }

            return ps;
        }
        },  new CrimeMapper());      



        return crimeList;   

    }

在线：

PreparedStatement ps =(PreparedStatement) connection.prepareStatement(sql + whereClause);

您确定

PreparedStatement

是

java.sql.PreparedStatement

---

不确定为什么需要强制转换从

连接返回的对象。prepareStatement（）

。此方法返回类型为

java.sql.PreparedStatement

的对象。如果正确导入类，请检查导入语句。

我在问题中包含了导入确定我的错误，我将其更改为java.sql.PreparedStatement ps=connection.preparest陈述（sql+where子句）；它是有效的。非常感谢你的帮助

PreparedStatement ps =(PreparedStatement) connection.prepareStatement(sql + whereClause);