JDBC中处理大段文本数据

package jdbc;


import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.Reader;
import java.io.Writer;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

/**
 *
 * @author HaoWang
 */
public class ClobTest {
    public static void main(String[] args) {
        create(1,"C:\\a.txt");
        read(1,"C:\\a_bak.txt");
    }
    public static void create(int cid, String txtPath) {
        Connection conn = null;
        PreparedStatement ps = null;
        String sql = null;
        ResultSet rs = null;
        try {
            conn = JdbcUtils.getConnection();
            sql = "insert into clob_test(cid,content) value(?,?)";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, cid);
            File file = new File(txtPath);
            Reader reader = new BufferedReader(new FileReader(file));

            ps.setCharacterStream(2, reader, file.length());
            int i = ps.executeUpdate();
            System.out.println("i="+i);
            reader.close();
        } catch (Exception ex) {
            System.out.println(ex.toString());
        } finally {
            JdbcUtils.free(conn, ps, rs);
        }
    }
    public static void read(int cid, String txtPath) {
        Connection conn = null;
        PreparedStatement ps = null;
        String sql = null;
        ResultSet rs = null;
        try {
            conn = JdbcUtils.getConnection();
            sql = "Select content from clob_test where cid=?";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, cid);
            rs = ps.executeQuery();
            while(rs.next()) {
                System.out.println(rs.getString(cid));  //直接获得文本内容
//                Clob clob = rs.getClob(cid);
//                Reader reader = clob.getCharacterStream();
                Reader reader = rs.getCharacterStream(cid);
                File file = new File(txtPath);
                Writer writer = new BufferedWriter(new FileWriter(file));
                char[] buff = new char[1024];
                for(int i=0; (i=reader.read(buff))>0;) {
                    writer.write(buff, 0, i);
                }
                writer.close();
                reader.close();
            }
        } catch (Exception ex) {
            System.out.println(ex.toString());
        } finally {
            JdbcUtils.free(conn, ps, rs);
        }
    }
}