Mybatis Blob类型部分转换失败问题

今天遇到这个问题也是很奇葩，一开始在转换类里面疯狂打断点，打印出来的也是乱码。还有就是我只挑了两三条数据搁那边测，导致一开始找的问题的方向就有点偏。

直接上解决办法！

public class MyBlobTypeHandler extends BaseTypeHandler<String> {
    private static Logger logger = LoggerFactory.getLogger(MyBlobTypeHandler.class);
    //###指定字符集
    private static final String UTF8_charset = "UTF-8";

    @Override
    public void setNonNullParameter(PreparedStatement preparedStatement, int i, String s, JdbcType jdbcType) throws SQLException {
        byte[] bytes = new byte[1024];
        try {
            // 把String转化成byte流
            bytes = s.getBytes(UTF8_charset);
        } catch (UnsupportedEncodingException e) {
            logger.error("String 转 blob 失败...msg: {}", e.getMessage());
            throw new RuntimeException("Blob Encoding Error!");
        }
        preparedStatement.setBytes(i, bytes);
    }

    @Override
    public String getNullableResult(ResultSet resultSet, String s) throws SQLException {
        if(resultSet.getBytes(s) == null){
            return null;
        }
        byte[] returnValue = resultSet.getBytes(s);
        try {
            // 把byte转化成string
            return new String(returnValue, UTF8_charset);
        } catch (UnsupportedEncodingException e) {
            logger.error("blob 转 String 失败...msg: {}", e.getMessage());
            throw new RuntimeException("Blob Encoding Error!");
        }
    }

    @Override
    public String getNullableResult(ResultSet resultSet, int i) throws SQLException {
        if(resultSet.getBytes(i) == null) {
            return null;
        }
        byte[] returnValue = resultSet.getBytes(i);
        try {
            return new String(returnValue, UTF8_charset);
        } catch (UnsupportedEncodingException e) {
            logger.error("blob 转 String 失败...msg: {}", e.getMessage());
            throw new RuntimeException("Blob Encoding Error!");
        }
    }

    @Override
    public String getNullableResult(CallableStatement callableStatement, int i) throws SQLException {
        return null;
    }
}

请看好这段代码:

// 错误的是
byte[] bytes = null;
// 修改为
byte[] bytes = new byte[1024];

没错，基本的数据长度小了！我当时也是没注意发现到有的存储大小只是byte而有的已经是kb了。修改了一下，就好了.....