public class ResourceContentDTO extends BaseDTO implements Serializable {
	private static final long serialVersionUID = 1L;
	
	/** 内容字段 需要用Byte数组接受 */
	private byte[] fileContent;

	public byte[] getFileContent() {
		return fileContent;
	}

	public void setFileContent(byte[] fileContent) {
		this.fileContent = fileContent;
	}
}

  SQL

        <resultMap id="resContentMap" class="resContentDTO">
		 <result property="fileContent" column="FILE_CONTENT" jdbcType="BLOB"/>
	</resultMap>
	
    <select id="getResourceXmlContentListByResourceId" resultMap="resContentMap" parameterClass="java.lang.String">
       SELECT RC.FILE_CONTENT  AS FILE_CONTENT
         FROM INF_RESOURCE_CONTENT RC
        WHERE RC.ONLINE_FLAG = 1
          AND RC.RESOURCE_ID = #resourceId#    
    </select>

  读取:

byte[] fileContent = resourceContentDTO.getFileContent();
String fileContentStr = "";
fileContentStr = new String(fileContent, "UTF-8");