关于代码查询数据库BLOB数据

Question

Class.forName("oracle.jdbc.OracleDriver");
String url = "jdbc:oracle:thin:@192.168.1.5:1521:orcl";
Connection con = DriverManager.getConnection(url,"mj","123");
byte[] b = new byte[] {'a','b','c','d','e','f','g','h','i','j'};
Statement s = con.createStatement();
// s.exeute("insert into t2 values(1,'ASDADD',EMPTY_BLOB())");
// ResultSet rs = s.executeQuery("select b from t2 for update");
// while(rs.next()){
// BLOB blob = (BLOB) rs.getBlob("B");
// OutputStream os = blob.getBinaryOutputStream();
// os.write(b);
// os.close();
// }

    Statement s1 = con.createStatement();
    ResultSet rs1 = s1.executeQuery("select B from t2 for update");
    while(rs1.next()){
        BLOB blob = (BLOB) rs1.getBlob("B");
        System.out.println(blob.length());
    }
    注释掉上面的代码，后面的blob.length()输出九尾0了，不注释，输出为10.这是什么原因

Answer 1

http://blog.csdn.net/mengdong_zy/article/details/7406945