11_传智播客JDBC_用jdbc访问大段文本数据

快捷键 F3 = ctrl+鼠标左键

package five.base;
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 five.utils.Utils;

// 快捷键 F3 = ctrl+鼠标左键
public class BlobTest {

/**
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {

//create(3, "c:/1.txt");
read(3);

}
public static void create( int id, String fileName) throws IOException{

Connection connection = null;

PreparedStatement ps = null;

ResultSet rs = null;

try {
connection = Utils.getConnection();
String sql = "insert into clob (id, test) values (?,?)";
ps = connection.prepareStatement(sql);

File file = new File(fileName);
//装饰模式 带有缓冲区 读取 效率高
Reader reader = new BufferedReader(new FileReader(file));

ps.setInt(1, id);
// 前提 Ascii
// parameterIndex - the first parameter is 1, the second is 2, ...
// x - the Java input stream that contains the ASCII parameter value
// length - the number of bytes in the stream
//ps.setAsciiStream(2, x, length)；

// 字节流
ps.setCharacterStream(2, reader, (int)file.length());
int i = ps.executeUpdate();
reader.close();
System.out.println(i);
} catch (SQLException e) {
e.printStackTrace();
}finally{
Utils.free(connection, ps, rs);
}

}
static void read(int id) throws Exception {

Connection connection = null;
PreparedStatement ps = null;
ResultSet rs = null;

try {
connection = Utils.getConnection();
String sql = "select test from clob";
ps = connection.prepareStatement(sql);
rs = ps.executeQuery();
// 5 处理结果
while (rs.next()) {
//Clob clob = rs.getClob(1);
//Reader reader = clob.getCharacterStream();
String test = rs.getString(1);
System.out.println(test);
Reader reader = rs.getCharacterStream("test");
File file = new File("D:/cgz/dayByDayJdbc/Base_Bak.txt");
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 {
Utils.free(connection, ps, rs);
}
}

}