自定义JacksonTypeHandler通用版本

增删改能生效,但是保存数据的格式异于平常,且查询失效。

我的操作如下:

1.自定义类JacksonTypeHandler,由于想要一次性解决所有的映射,所以这里我写成了 @MappedTypes({Object.class})

/**
 * 通用类型的TypeHandler
 */
@Slf4j
@MappedTypes({Object.class})
@MappedJdbcTypes(JdbcType.VARCHAR)
public class JacksonTypeHandler extends BaseTypeHandler {

	private static ObjectMapper objectMapper;
    private Class type;

    static {
        objectMapper = new ObjectMapper();
    }

    public JacksonTypeHandler(Class type) {
        if (log.isTraceEnabled()) {
            log.trace("JacksonTypeHandler(" + type + ")");
        }
        if (null == type) {
            throw new MybatisPlusException("Type argument cannot be null");
        }
        this.type = type;
    }

    private Object parse(String json) {
        try {
            if (json == null || json.length() == 0) {
                return null;
            }
            return objectMapper.readValue(json, type);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private String toJsonString(Object obj) {
        try {
            return objectMapper.writeValueAsString(obj);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public Object getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return parse(rs.getString(columnName));
    }

    @Override
    public Object getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
        return parse(rs.getString(columnIndex));
    }

    @Override
    public Object getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return parse(cs.getString(columnIndex));
    }

    @Override
    public void setNonNullParameter(PreparedStatement ps, int columnIndex, Object parameter, JdbcType jdbcType) throws SQLException {
        ps.setString(columnIndex, toJsonString(parameter));
    }
}
 
  

                            
                        
                    
                    
                    

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