java - 如何将serialClob转换为String格式？

Question

我正在尝试将serialclob 转换为字符串。但我没有成功。我认为我没有以正确的方式做事。我的代码是:

char[] buffer;
        int count = 0;
        int length = 0;
        String data = null;
        String[] type;
        StringBuffer sb;
        try{
            SqlRowSet rows = getJdbcTemplate().queryForRowSet("select c.BOUNDING_BOX.GET_WKT() BOUNDING_BOX FROM EXAMPLE c WHERE EXAMPLE_ID = 100",
                    new Object[] {subid});
            SubscriptionModel subscription = new SubscriptionModel();
            System.out.println("bbox");
            SqlRowSetMetaData rsmd = rows.getMetaData();
                type = new String[rsmd.getColumnCount()];
                for(int col=0;col<rsmd.getColumnCount();col++)
                    type[col] = rsmd.getColumnTypeName(col + 1);
                System.out.println("Read rows and only serial clob data type values");
            while(rows.next()){
                System.out.println("test 1 here");
                for(int col=0;col<rsmd.getColumnCount();col++){
                    System.out.println("test 2 here");
                    if("CLOB".equals(type[col]){
                        System.out.println("test 3 here");
                        SerialClob clob = (SerialClob) ((ResultSet) rows).getClob(col + 1);
                        if(clob != null){
                            System.out.println("clob is not null");
                            Reader is = clob.getCharacterStream();

                            sb = new StringBuffer();
                            length = (int) clob.length();

                            if(length>0){
                                buffer = new char[length];
                                count = 0;
                                try{
                                    while((count = is.read(buffer)) != -1)
                                        sb.append(buffer);

                                    data = new String(sb);
                                }catch(Exception e){

                                }
                            }
                            else
                                data = (String) null;
                        }else
                            data = (String) null;
                    }else{
                        data = (String) rows.getObject(col + 1);
                    }
                }
            }
            return subscription;
    }catch(Exception e){
        e.printStackTrace();
    }

但我收到如下错误:

bbox
Read rows and only serial clob data type values
test 1 here
test 2 here
java.lang.ClassCastException: javax.sql.rowset.serial.SerialClob cannot be cast to java.lang.String

我的错误在哪里？

Answer 1

这至少是一个问题:

if(type[col] == "CLOB")

这是直接比较字符串引用。我怀疑这会更好:

if ("CLOB".equals(type[col]))

这将使您进入正确的 if block 。我没有详细查看您的其余代码 - 如果您可以将其分解为更小的方法，那么阅读和维护会更简单。