jdbcTemplate获取mysql的blob

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java使用jdbcTemplate操作mysql数据库，遇到blob字段，正常读取出来是blob的地址，而不是blob的内容。

下面采用2中方式读取blob的内容：

1、以二进制数组形式读取blob，适用于文本数据

public void testJdbc(){ApplicationContext ctx = new ClassPathXmlApplicationContext("restlet-servlet.xml");JdbcTemplate jdbcTemplate = (JdbcTemplate)ctx.getBean("jdbcTemplate");String sql = "select * from violation_redis t where t.id < 10";final LobHandler lobHandler=new DefaultLobHandler();  @SuppressWarnings("unchecked")List<Map<String,String>> list = jdbcTemplate.query(sql,new RowMapper(){public Object mapRow(ResultSet rs, int rowNum) throws SQLException {//以二进制的数组方式获得Blob数据,第二个参数3是指blob字段在结果集的位置byte[] attach = lobHandler.getBlobAsBytes(rs, 3);//非blob子弹获取String key = rs.getString("vio_key");String strAttach = new String(attach);p(key + "==" + strAttach);Map<String,String> map = new HashMap<String,String>();map.put("vio_key", key);map.put("vio_info", strAttach);return map;}});p(list);}

2、流模式读取blob:

public void getBlob(OutputStream  out){String sql = "select * from violation_redis t where t.id < 10";final LobHandler lobHandler=new DefaultLobHandler();  List<Map<String,String>> list = jdbcTemplate.query(sql,new RowMapper(){public Object mapRow(ResultSet rs, int rowNum) throws SQLException {//以二进制的数组方式获得Blob数据InputStream is = lobHandler.getBlobAsBinaryStream(rs, 2);if(is != null){//利用spring的工具类将输入流的数据复制到输出流中FileCopyUtils.copy(is, out);}});}

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