[5]用jdbc访问大段文本数据(CLOB大字段使用字符流)
import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.io.Reader;import java.io.Writer;import java.sql.Clob;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class ClobTest {/** * @param args * @throws IOException * @throws SQLException */public static void main(String[] args) throws SQLException, IOException {// create();read();}static void read() throws SQLException, IOException {Connection conn = null;Statement st = null;ResultSet rs = null;try {// 2.建立连接conn = JdbcUtils.getConnection();// conn = JdbcUtilsSing.getInstance().getConnection();// 3.创建语句st = conn.createStatement();// 4.执行语句rs = st.executeQuery("select big_text from clob_test");// 5.处理结果while (rs.next()) {Clob clob = rs.getClob(1);Reader reader = clob.getCharacterStream();// reader = rs.getCharacterStream(1);// String s = rs.getString(1);File file = new File("JdbUtils_bak.java");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();}} finally {JdbcUtils.free(rs, st, conn);}}static void create() throws SQLException, IOException {Connection conn = null;PreparedStatement ps = null;ResultSet rs = null;try {// 2.建立连接conn = JdbcUtils.getConnection();// conn = JdbcUtilsSing.getInstance().getConnection();// 3.创建语句String sql = "insert into clob_test(big_text) values (?) ";ps = conn.prepareStatement(sql);File file = new File("src/cn/itcast/jdbc/JdbcUtils.java");Reader reader = new BufferedReader(new FileReader(file));ps.setCharacterStream(1, reader, (int) file.length());// ps.setString(1, x);// 4.执行语句int i = ps.executeUpdate();reader.close();System.out.println("i=" + i);} finally {JdbcUtils.free(rs, ps, conn);}}}
?用jdbc访问大段文本数据
