oracle Clob类型转换成String类型

转载：https://www.cnblogs.com/itmyhome/p/4131339.html

Clob类型转换成String类型

oracle中表结构如下：

create table GRID_RESOURCE
(
  ID         VARCHAR2(50),
  CNNAME     VARCHAR2(50),
  TYPE       VARCHAR2(50),
  PARENTID   VARCHAR2(50),
  VIEWWIDTH  VARCHAR2(50),
  REQUESTURL VARCHAR2(256),
  COUNTSQL   CLOB,
  ISDISPLAY  VARCHAR2(50),
  TREEINDEX  VARCHAR2(256),
  TABLES     VARCHAR2(256),
  NOTE3      VARCHAR2(256)
)

COUNTSQL字段为CLOB类型，索引为6

import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.sql.Clob;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class T {

    public static final SessionFactory sessionFactory;
    static {
        try {
            sessionFactory = new Configuration().configure()
                    .buildSessionFactory();
        } catch (Throwable ex) {
            throw new ExceptionInInitializerError(ex);
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        new T().getList();
    }

    public void getList() {
        String querySQL = "select * from GRID_RESOURCE";
        String countSQL = "";
        List<Object[]> list = new ArrayList<Object[]>();
        // List o_list = new ArrayList();
        try {
            list = sessionFactory.openSession().createSQLQuery(querySQL).list();
            for (Object[] obj : list) {
                Map<String, Object> map = new HashMap<String, Object>();
                Clob sc = (Clob) obj[6];
                countSQL = ClobToString(sc);
                System.out.println(countSQL);
            }
            // 另一个遍历方法
            /*
             * for(Object obj:o_list){ Object oo[] = (Object[])obj;
             * System.out.println(oo[6]); }
             */
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 将字Clob转成String类型
    public String ClobToString(Clob sc) throws SQLException, IOException {
        String reString = "";
        Reader is = sc.getCharacterStream();// 得到流
        BufferedReader br = new BufferedReader(is);
        String s = br.readLine();
        StringBuffer sb = new StringBuffer();
        while (s != null) {// 执行循环将字符串全部取出付值给StringBuffer由StringBuffer转成STRING
            sb.append(s);
            s = br.readLine();
        }
        reString = sb.toString();
        return reString;
    }

}