jdk8+Mybatis3.5.0+Mysql讀取LongBlob失敗

問題：在mysql中存儲base64，因為太長，基本就是幾百K，所以用longBlob

描述：在mysql中，LongBlob、blob算是二進制流文件了，所以用普通的數據格式是不行的，這里用TypeHandler解決，有其他覺得方案歡迎在下方留言

解決：

Handler代碼

import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;

import java.io.ByteArrayInputStream;
import java.io.UnsupportedEncodingException;
import java.sql.*;

public class MyBlobTypeHandler extends BaseTypeHandler<String> {
    // 指定字符集  
    private static final String DEFAULT_CHARSET = "utf-8";

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType) throws SQLException {
        ByteArrayInputStream bis;
        try {
            // 把String轉化成byte流  
            bis = new ByteArrayInputStream(parameter.getBytes(DEFAULT_CHARSET));
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("Blob Encoding Error!");
        }
        ps.setBinaryStream(i, bis, parameter.length());
    }

    @Override
    public String getNullableResult(ResultSet rs, String columnName) throws SQLException {
        return getResult(rs.getBlob(columnName));
    }

    @Override
    public String getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        return getResult(cs.getBlob(columnIndex));
    }

    @Override
    public String getNullableResult(ResultSet rs, int columnName) throws SQLException {
        return getResult(rs.getBlob(columnName));

    }

    private String getResult(Blob blob) throws SQLException {
        byte[] returnValue = null;
        if (null != blob) {
            returnValue = blob.getBytes(1, (int) blob.length());
        }
        try {
            // 把byte轉化成string
            if (null != returnValue) {
                return new String(returnValue, DEFAULT_CHARSET);
            }
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("Blob Encoding Error!");
        }
        return null;
    }
}

mybatis XML代碼

<result property="signature" column="signature" typeHandler="com.kenary.config.MyBlobTypeHandler"/>