jdbc 連接 mysql

jdbc 連接 mysql

一、安裝

ubuntu(linux)下安裝mysql
$ sudo apt-get update
$ sudo apt-get install mysql-server mysql-client

安裝完成後會讓你設置一下root用戶的密碼，這裏的root用戶是mysql的root用戶，和系統的root用戶不同。

登錄mysql
mysql -uroot -p

二、設置遠程連接

主要設置兩個點， 
1. mysql的監聽端口(3306)是不是阻止的，主要看防火牆。
ubuntu防火牆設置 可以參考 http://blog.csdn.net/u012480384/article/details/50822304

windows條件下，自行百度一下，應該有很多。

2. mysql內部設置遠程連接，並授權。

vim /etc/my.cnf
註釋這一行：bind-address=127.0.0.1 ==> #bind-address=127.0.0.1
保存退出。
對應的window版本的 mysql 目錄下 my.cnf 文件 

設置mysql：

#登錄mysql
mysql -uroot -p
#切換到 'mysql'數據庫，修改遠程連接的基本信息，保存在mysql數據庫中，因此使用mysql數據庫。
mysql> use mysql;

#  *.* 用來設置 數據庫和表名
#  To 'root'@'%' 用來設置得到授權的用戶和所在的ip。
#  By 'root' 表示得到授權用戶的登錄密碼
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;

# 刷新授權，使之生效
mysql> flush privileges;

# 檢驗
mysql> select host,user from user;

三、 java 代碼

首選需要引入mysql jdbc的jar包
Java連接MySQL的最新驅動包下載地址 
http://www.mysql.com/downloads/connector/j

java代碼

package com.test.mysql;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.DatabaseMetaData;

import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;

//MySQL的JDBC URL編寫方式：jdbc:mysql://主機名稱：連接端口/數據庫的名稱?參數=值
// 避免中文亂碼要指定useUnicode和characterEncoding
// 執行數據庫操作之前要在數據庫管理系統上創建一個數據庫，名字自己定，
// 下面語句之前就要先創建javademo數據庫

public class MysqlHelper {

    // public static final String url = "jdbc:mysql://127.0.0.1:3306/student";
    public static final String MYSQL_JDBC = "jdbc:mysql://192.168.1.164:3306/student";
    public static final String MYSQL_DRIVER = "com.mysql.jdbc.Driver";
    public static final String MYSQL_USER = "root";
    public static final String MYSQL_PASSWORD = "root";

    public static final String MYSQL_URL = MYSQL_JDBC + "?user=root&password=root&useUnicode=true&characterEncoding=UTF8";

    public static final String TABLE_NAME = "student";
    public static final String TABLE_COLUMN = TABLE_NAME + "(name)";

    private Connection conn = null;
    // private PreparedStatement pst = null;

    public MysqlHelper() {
        try {
            Class.forName(MYSQL_DRIVER);// 指定連接類型
            System.out.println("成功加載MySQL驅動程序");

            conn = (Connection) DriverManager.getConnection(MYSQL_URL);// 獲取連接

            conn.setCharacterEncoding("utf8");
            conn.setUseCompression(true);
            if (conn.getUseCompression()) {
                System.out.println("compress");
            } else {
                System.out.println("UnCompress");
            }
            // pst = conn.prepareStatement(sql);// 準備執行語句
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void execute(String sql) {
        if (null == sql || 0 == sql.length()) {
            System.out.println("argu wrong");
            return;
        }

        System.out.println(sql);
        Statement stmt;
        try {
            stmt = conn.createStatement();
            int result = stmt.executeUpdate(sql);
            if (-1 == result) {
                System.out.println("execute failure " + result);
            } else {
                System.out.println("execute successed " + result);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    private void executeQuery(String sql) {
        if (null == sql || 0 == sql.length()) {
            System.out.println("argu wrong");
            return;
        }

        ResultSet rs = null;
        System.out.println(sql);
        Statement stmt;
        try {
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
            System.out.println("\n############");
            while (rs.next()) {
                System.out.println(rs.getInt("id") + " " + rs.getString("name"));
            }
            System.out.println("############\n");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void insert(String name) {
        if (null == name || 0 == name.length())
            name = "default";
        String sql = "insert into " + TABLE_COLUMN + " values('" + name + "')";
        execute(sql);
    }

    public void insert(List<String> list) {
        if (null == list || 0 == list.size())
            return;
        StringBuilder names = new StringBuilder();
        int i = 0;
        for (i = 0; i < list.size() - 1; ++i) {
            names.append("('" + list.get(i) + "'), ");
        }
        names.append("('" + list.get(i) + "')");
        String sql = "insert into " + TABLE_COLUMN + " values" + names.toString();
        execute(sql);
    }

    public void delete(int id) {
        String sql = "delete from " + TABLE_NAME + " where id = " + id;
        execute(sql);
    }

    public void delete(String name) {
        if (null == name || 0 == name.length())
            name = "default";
        String sql = "delete from " + TABLE_NAME + " where name = '" + name + "'";
        execute(sql);
    }

    public void deleteAll() {
        String sql = "delete from " + TABLE_NAME;
        execute(sql);
    }

    public void update(int id, String name) {
        if (null == name || 0 == name.length())
            name = "default";
        String sql = "update student set name='" + name + "' where id = " + id;
        execute(sql);
    }

    public void select(int id) {
        String sql = "select * from " + TABLE_NAME + " where id = " + id;
        executeQuery(sql);
    }

    public void selectAll() {
        String sql = "select * from " + TABLE_NAME;
        executeQuery(sql);
    }

    public void createTable() {
        createTable(TABLE_NAME);
    }

    public void createTable(String tableName) {
        if (null == tableName || 0 == tableName.length())
            tableName = TABLE_NAME;
        if (!hasTable(tableName)) {
            String sql = "create table " + tableName
                    + " (id int(4) not null primary key auto_increment,name varchar(20) not null)engine=innodb default charset=utf8";
            execute(sql);
        }
    }

    public boolean hasTable(String tableName) {
        if (null == tableName || 0 == tableName.length())
            tableName = TABLE_NAME;
        DatabaseMetaData meta = null;
        ResultSet result = null;
        try {
            meta = (DatabaseMetaData) conn.getMetaData();
            result = meta.getTables(null, null, tableName, null);
            if (result.next())
                return true;
            return false;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return false;
    }

    public void dropTable(String tableName) {
        if (null == tableName || 0 == tableName.length())
            tableName = TABLE_NAME;
        if (hasTable(tableName)) {
            String sql = "drop table " + tableName;
            execute(sql);
        }
    }

    public void dropTable() {
        dropTable(TABLE_NAME);
    }

    public void commit() {
        String sql = "commit";
        execute(sql);
    }

    public void close() {
        try {
            this.conn.close();
            // this.pst.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

測試代碼：

package com.test.mysql;

import java.util.Arrays;

public class MysqlDemo {

    public static String[] names = {"apple", "bob", "carry", "david"};

    public static void main(String[] args) throws Exception {
        // connect();
        // create();
        // drop();
        // insert();
        // update();
        // delete();
        // select();
        allTest();
        System.out.println("###########");
    }

    public static void connect() {
        MysqlHelper mysql = new MysqlHelper();
        mysql.close();
    }

    public static void create() {
        MysqlHelper mysql = new MysqlHelper();
        mysql.createTable();
        mysql.close();
    }

    public static void drop() {
        MysqlHelper mysql = new MysqlHelper();
        mysql.dropTable();
        mysql.close();
    }

    public static void insert() {
        MysqlHelper mysql = new MysqlHelper();
        mysql.insert(Arrays.asList(names));
        mysql.close();
    }

    public static void update() {
        MysqlHelper mysql = new MysqlHelper();
        mysql.update(1, "xoxo");
        mysql.close();
    }

    public static void delete() {
        MysqlHelper mysql = new MysqlHelper();
        mysql.delete("apple");
        mysql.close();
    }

    public static void select() {
        MysqlHelper mysql = new MysqlHelper();
        mysql.selectAll();
        mysql.close();
    }

    public static void allTest() {
        MysqlHelper mysql = new MysqlHelper();
        if (mysql.hasTable(MysqlHelper.TABLE_NAME)) {
            mysql.dropTable();
        }
        mysql.createTable();
        mysql.insert(Arrays.asList(names));
        mysql.selectAll();
        mysql.update(1, "xoxo");
        mysql.selectAll();
        mysql.delete(1);
        mysql.selectAll();
        try {
            Thread.sleep(3000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        mysql.commit();
        mysql.dropTable();
        mysql.close();
    }

}