ClobTest BlobTest

package cn.itcast.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 *
 * 2008-12-6
 *
 * @author <a href="mailto:[email protected]">李勇</a>
 *
 */
public final class JdbcUtils {
    private static String url = "jdbc:mysql://localhost:3306/jdbc";
    private static String user = "root";
    private static String password = "";

    private JdbcUtils() {
    }

    static {
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            throw new ExceptionInInitializerError(e);
        }
    }

    public static Connection getConnection() throws SQLException {
        return DriverManager.getConnection(url, user, password);
    }

    public static void free(ResultSet rs, Statement st, Connection conn) {
        try {
            if (rs != null)
                rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (st != null)
                    st.close();
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                if (conn != null)
                    try {
                        conn.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
            }
        }
    }
}

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;

/**
 *
 * 2008-12-6
 *
 * @author <a href="mailto:[email protected]">liyong</a>
 *
 */
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);
        }
    }

}

package cn.itcast.jdbc;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 *
 * 2008-12-6
 *
 * @author <a href="mailto:[email protected]">liyong</a>
 *
 */
public class BlobTest {

    /**
     * @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_bit  from blob_test");

            // 5.处理结果
            while (rs.next()) {
                // Blob blob = rs.getBlob(1);
                // InputStream in = blob.getBinaryStream();
                InputStream in = rs.getBinaryStream("big_bit");

                File file = new File("IMG_0002_bak.jpg");
                OutputStream out = new BufferedOutputStream(
                        new FileOutputStream(file));
                byte[] buff = new byte[1024];
                for (int i = 0; (i = in.read(buff)) > 0;) {
                    out.write(buff, 0, i);
                }
                out.close();
                in.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 blob_test(big_bit) values (?) ";
            ps = conn.prepareStatement(sql);
            File file = new File("IMG_0002.jpg");
            InputStream in = new BufferedInputStream(new FileInputStream(file));

            ps.setBinaryStream(1, in, (int) file.length());
            // 4.执行语句
            int i = ps.executeUpdate();

            in.close();

            System.out.println("i=" + i);
        } finally {
            JdbcUtils.free(rs, ps, conn);
        }
    }
}