利用xml文件封装数据库配置信息
xml文件放在src目录下
/testjdbc1/src/DBUtil.xml
<?xml version="1.0" encoding="GBK" ?>
<sxtConfig>
<!-- 本次 连接 mysql 数据库-->
<database-type>mysql</database-type>
<database type="oracle">
<className>oracle.jdbc.driver.OracleDriver</className>
<url>jdbc:oracle:thin:@localhost:1521:orcl</url>
<user>scott</user>
<pwd>tiger</pwd>
</database>
<database type="mysql">
<className>com.mysql.jdbc.Driver</className>
<url>jdbc:mysql://localhost:3306/test</url>
<user>root</user>
<pwd>clc</pwd>
</database>
</sxtConfig>
java文件解析xml文件,封装方法
/testjdbc1/src/dbutil/JDBCUtil.java
package dbutil;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
public class JDBCUtil {
public static String className;
public static String url ;
public static String user;
public static String pwd ;
/**
* DOM4j解析xml
*/
static {
try {
// 开始解析配置文件
SAXReader saxReader = new SAXReader();
// 以流的方式读取配置文件
InputStream inputStream = JDBUtil.class.getClassLoader().getResourceAsStream("DBUtil.xml");
// 开始配置文件
Document document = saxReader.read(inputStream);
// 获取根节点
Element rootElement = document.getRootElement();
// 获取要选择的数据库类型
String databaseType = rootElement.elementText("database-type");
// 判断数据库类型是否为空
if (databaseType != null) {
// 遍历出数据库的配置信息
List<Element> elements = rootElement.elements("database");
for (Element element : elements) {
// 判断数据库是否一致
if (databaseType.equals(element.attributeValue("type"))) {
// 获取当前元素的所有子元素
className = element.elementText("className");
url = element.elementText("url");
user = element.elementText("user");
pwd = element.elementText("pwd");
}
}
// 使用静态代码块加载驱动
Class.forName(className);
} else {
System.out.println("您的配置文件数据库类型【database-type】有误，请重新配置");
}
} catch (DocumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 创建JDBC连接 connection的连接和事务的提交方式
*/
public static Connection createConnection() {
return createConnection(true);
}
// 事务的提交
private static Connection createConnection(boolean autoCommit) {
// 声明连接
Connection connection = null;
try {
// 获取连接
connection = DriverManager.getConnection(url, user, pwd);
// 事务的提交方式
connection.setAutoCommit(autoCommit);
System.out.println("数据库连接成功");
} catch (SQLException e) {
System.out.println("您的数据库详细配置有误url【" + url + "】user【" + user + "】pwd【" + pwd + "】");
e.printStackTrace();
}
return connection;
}
/**
* 获取发送器 statement
*/
public static Statement createStatemen(Connection connection) {
Statement statement = null;
try {
statement = connection.createStatement();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return statement;
}
/**
* 获取预处理发送器
*/
public static PreparedStatement createPreparedStatement(Connection connection, CharSequence sql) {
PreparedStatement preparedStatement = null;
try {
preparedStatement = connection.prepareStatement(sql.toString());
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return preparedStatement;
}
/**
* 关闭连接connection
*/
private static void closeConnection(Connection connection) {
if (connection != null) {
try {
connection.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/**
* 关闭发送器statement
*/
private static void closeStatement(Statement statement) {
if (statement != null) {
try {
statement.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/**
* 关闭连接resultSet
*/
private static void closeResultSet(ResultSet resultSet) {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/**
* 关闭所有连接 connection statement resultSet
*/
public static void closeAll(Connection connection, Statement statement, ResultSet resultSet) {
closeResultSet(resultSet);
closeStatement(statement);
closeConnection(connection);
}
}
测试连接
package testoracle;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import dbutil.JDBUtil;
public class TestDBUtil {
public static void main(String[] args) {
//声明连接
Connection connection=null;
Statement statement=null;
ResultSet resultSet=null;
//sql
String sql="SELECT * FROM EMP";
try {
//获取连接
connection=JDBUtil.createConnection();
//获取发送器
statement=JDBUtil.createStatement(connection);
//发送sql语句
resultSet=statement.executeQuery(sql);
while (resultSet.next()) {
System.out.print(resultSet.getString(1)+"\t");
System.out.print(resultSet.getString(2)+"\t");
System.out.print(resultSet.getString(3)+"\t");
System.out.print(resultSet.getString(4)+"\t");
System.out.println(resultSet.getString(5)+"\t");
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally {
//关闭连接
JDBUtil.closeAll(statement, connection, resultSet);
} }
}
数据库中插入日期类型的数据的方式:
preparedStatement.setTimestamp(2, new java.sql.Timestamp(user.getUpdateTime().getTime()));