操作步骤：
1.注册数据库驱动程序
2.获取数据库连接对象
3.建立数据库操作语句
4.执行并返回结果
5.释放连接
CODE
1. 配置peoperties属性文件
DRIVERS=oracle.jdbc.driver.OracleDriver
URL=jdbc：oracle：thin：@localhost：1521：orcl
USERNAME=user
PASSWORD=password
2. 解析配置文件属性
package com.jdbc; import java.io.IOException;
import java.io.InputStream;
import java.util.Properties; public class DBConfig extends Properties{
private static final long serialVersionUID = 6988299229093520679L;
private static DBConfig dbConfig = null;
private DBConfig() {
try{
InputStream inStream = DBConfig.class.getResourceAsStream("/dbConfig.properties");
this.load(inStream);
}catch (IOException e) {
e.printStackTrace();
}
}
public static DBConfig getInstance() {
if(dbConfig == null){
synchronized (DBConfig.class) {
if(dbConfig == null){
dbConfig = new DBConfig();
}
}
}
return dbConfig;
}
} |
3. 加载驱动获取连接操作
package com.jdbc; import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement; public class DBUtils { private static String DB_DRIVERS;
private static String DB_URL;
private static String DB_USER;
private static String DB_PASSWORD;
static {
DBConfig config = DBConfig.getInstance();
DB_DRIVERS = config.getProperty(DBConstant.DB_DRIVERS);
DB_URL = config.getProperty(DBConstant.DB_URL);
DB_USER = config.getProperty(DBConstant.DB_USERNAME);
DB_PASSWORD = config.getProperty(DBConstant.DB_PASSWORD);
}
/**
* 获取数据库连接
* @return conn 数据库连接
* @throws ClassNotFoundException if the class cannot be located
* @throws SQLException if a database access error occurs
*/
public static Connection getConnection() throws ClassNotFoundException, SQLException{
Connection conn = null;
try {
// 1.注册数据库驱动程序
Class.forName(DB_DRIVERS);
// 2.获取数据库连接对象
conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
} catch (ClassNotFoundException e) {
throw new ClassNotFoundException("数据库驱动注册失败" + e.getMessage());
}catch (SQLException e) {
throw new SQLException("获取数据库连接对象失败" + e.getMessage());
}
return conn;
}
/**
* 释放数据库连接
*/
public static void release(ResultSet rs, Statement stmt, Connection conn) {
try {
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
} } |
4.操作
package com.jdbc; import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet; public class TestDb {
public static void main(String[] args) throws Exception {
String sql = "select * from producttype where typeid = ?";
// 获取数据库连接对象
Connection conn = DBUtils.getConnection();
// 建立数据库操作语句
PreparedStatement pstm = conn.prepareStatement(sql);
pstm.setInt(1, 21);
// 执行操作语句
ResultSet rs = pstm.executeQuery();
// 获取执行结果
while(rs.next()){
System.out.println(rs.getInt("typeid"));
}
// 关闭连接
DBUtils.release(rs, pstm, conn);
}
} |
常用JDBC驱动
Mysql | http://www.mysql.com/products/connector/j/ |
Oracle | http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/index.html |
SQL Server by jTDS | http://sourceforge.net/project/showfiles.php?group_id=33291 |
Postgres | http://jdbc.postgresql.org/download.html |
SAP DB | http://www.sapdb.org/sap_db_jdbc.htm |
SyBase by jTDS | http://jtds.sourceforge.net/ |