mysql Json和BLOB类型字段，mybatis 通用TypeHandler

package com.taylor.cep.database.mybatis.typehandler;

import org.apache.ibatis.type.baseTypeHandler;
import org.apache.ibatis.type.JdbcType;
import org.apache.ibatis.type.MappedJdbcTypes;

import java.io.ByteArrayInputStream;
import java.nio.charset.StandardCharsets;
import java.sql.*;


@MappedJdbcTypes({JdbcType.BLOB})
public class BlobTypeHandler  extends baseTypeHandler {

    public void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType) throws SQLException {
        ByteArrayInputStream bis;
        bis = new ByteArrayInputStream(parameter.getBytes(StandardCharsets.UTF_8));

        ps.setBinaryStream(i, bis, parameter.getBytes().length);
    }

    public String getNullableResult(ResultSet rs, String columnName) throws SQLException {
        Blob blob = rs.getBlob(columnName);
        return blobToString(blob);
    }

    private String blobToString(Blob blob) throws SQLException {
        byte[] returnValue;
        if (null != blob) {
            returnValue = blob.getBytes(1L, (int) blob.length());

            return new String(returnValue, StandardCharsets.UTF_8);
        } else {
            return "";
        }
    }

    public String getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        Blob blob = cs.getBlob(columnIndex);
        return blobToString(blob);
    }

    public String getNullableResult(ResultSet arg0, int arg1) throws SQLException {
        return null;
    }
}

package com.taylor.cep.database.mybatis.typehandler;


import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.ibatis.type.baseTypeHandler;
import org.apache.ibatis.type.JdbcType;

import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;



public class JsonTypeHandler extends baseTypeHandler {
    private static final ObjectMapper mapper = new ObjectMapper();
    private Class clazz;
    public JsonTypeHandler(Class clazz) {
        if (clazz == null) throw new IllegalArgumentException("Type argument cannot be null");
        this.clazz = clazz;
    }
    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, T parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(i, this.toJson(parameter));
    }
    @Override
    public T getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return this.toObject(rs.getString(columnName), clazz);
    }
    @Override
    public T getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        return this.toObject(rs.getString(columnIndex), clazz);
    }
    @Override
    public T getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return this.toObject(cs.getString(columnIndex), clazz);
    }
    private String toJson(T object) {
        try {
            return mapper.writevalueAsString(object);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    private T toObject(String content, Class clazz) {
        if (content != null && !content.isEmpty()) {
            try {
                return (T) mapper.readValue(content, clazz);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        } else {
            return null;
        }
    }
    static {
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
    }
}