mybatis查询text类型字段时返回Nclob,导致json格式化时报错

package cn.yuanqiao.archive.common.typeHandler;import com.alibaba.druid.proxy.jdbc.NClobProxyImpl;import org.apache.ibatis.type.*;import org.springframework.beans.factory.annotation.Value;import org.springframework.stereotype.Component;import java.io.BufferedReader;import java.io.IOException;import java.io.Reader;import java.io.StringReader;import java.sql.*;@MappedTypes(Clob.class)@MappedJdbcTypes(JdbcType.CLOB)@Componentpublic class NClobTypeHandler extends BaseTypeHandler<String> {    @Value("${YQ_DATABASE}")    private Integer databaseId;    @Override    public void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType) throws SQLException {        StringReader reader=new StringReader(parameter);        ps.setCharacterStream(i,reader,parameter.length());    }    @Override    public String getNullableResult(ResultSet rs, String columnName) throws SQLException {        String clobToString="";        try {            switch (databaseId) {                case 4://达梦数据库                    NClobProxyImpl aa=(NClobProxyImpl) rs.getObject(columnName);                    Clob rawClob = aa.getRawClob();                    clobToString = ClobToString(rawClob);                    break;                default:                    clobToString="长文本类型,无法显示";                    break;            }        } catch (SQLException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        return clobToString;    }    @Override    public String getNullableResult(ResultSet rs, int i) throws SQLException {        String clobToString="";        try {            switch (databaseId) {                case 4:                    NClobProxyImpl aa=(NClobProxyImpl) rs.getObject(i);                    Clob rawClob = aa.getRawClob();                    clobToString = ClobToString(rawClob);                    break;                default:                    clobToString="长文本类型,无法显示";                    break;            }        } catch (SQLException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        return clobToString;    }    @Override    public String getNullableResult(CallableStatement callableStatement, int i) throws SQLException {        String clobToString="";        try {            switch (databaseId) {                case 4:                    NClobProxyImpl aa=(NClobProxyImpl) callableStatement.getObject(i);                    Clob rawClob = aa.getRawClob();                    clobToString = ClobToString(rawClob);                    break;                default:                    clobToString="长文本类型,无法显示";                    break;            }        } catch (SQLException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        return clobToString;    }    private String ClobToString(Clob clob) throws SQLException, IOException {        String reString = "";        Reader is = clob.getCharacterStream();// 得到流        BufferedReader br = new BufferedReader(is);        String s = br.readLine();        StringBuffer sb = new StringBuffer();        while (s != null) {// 执行循环将字符串全部取出付值给StringBuffer由StringBuffer转成STRING            sb.append(s);            s = br.readLine();        }        reString = sb.toString();        return reString;    }}

来源地址：https://blog.csdn.net/weixin_43484846/article/details/133776124