数据库中使用Clob处理长文本

package cn.itcast.jdbc;

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;

//大字符串处理
public class ClobTest {

public static void main(String[]args) throws SQLException, IOException{
//      create();
read();
}

static void create() throws SQLException, IOException {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;

try {
conn = JdbcUtils.getConnection();
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());   //字符流

int i = ps.executeUpdate();

reader.close();
System.out.println("i=" + i);

} finally {
JdbcUtils.free(rs, ps, conn);
}
}

static void read() throws SQLException, IOException {
Connection conn = null;
Statement st = null;
ResultSet rs = null;

try {
conn = JdbcUtils.getConnection();

st = conn.createStatement();

rs = st.executeQuery("select big_text from clob_test");

while (rs.next()) {
//读取大文本，方式1
Clob clob=rs.getClob("big_text");
Reader reader=clob.getCharacterStream();

//读取大文本，方式2
//Reader reader=rs.getCharacterStream(1);

//读取大文本，方式3
//String s=rs.getString(1);
//System.out.println();
File file=new File("JdbcUtils.java");
Writer writer=new BufferedWriter(new FileWriter(file));
char[]buff=new char[1024];  //缓冲区
for(int i=0;(i=reader.read(buff))>0;)
writer.write(buff,0,i);

writer.close();
reader.close();
}

} finally {
JdbcUtils.free(rs, st, conn);
}
}
}