jdbc.properties属性文件
driverClass=com.mysql.jdbc.Driver
url=jdbc:mysql:///jdbctest
username=root
password=1234
JDBCUtils.java工具类
package com.imooc.jdbc.utils;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
/**
* JDBC的工具类
* @author jt
*
*/
public class JDBCUtils {
private static final String driverClass;
private static final String url;
private static final String username;
private static final String password;
static{
// 加载属性文件并解析：
Properties props = new Properties();
// 如何获得属性文件的输入流？
// 通常情况下使用类的加载器的方式进行获取：
InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");
try {
props.load(is);
} catch (IOException e) {
e.printStackTrace();
}
driverClass = props.getProperty("driverClass");
url = props.getProperty("url");
username = props.getProperty("username");
password = props.getProperty("password");
}
/**
* 注册驱动的方法
* @throws ClassNotFoundException
*/
public static void loadDriver() throws ClassNotFoundException{
Class.forName(driverClass);
}
/**
* 获得连接的方法:
* @throws SQLException
*/
public static Connection getConnection() throws Exception{
loadDriver();
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
/**
* 资源释放
*/
public static void release(Statement stmt,Connection conn){
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
public static void release(ResultSet rs,Statement stmt,Connection conn){
if(rs!= null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs = null;
}
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
JDBCDemo3.java测试
package com.imooc.jdbc.demo1;
import java.sql.Connection;
import java.sql.Statement;
import org.junit.Test;
import com.imooc.jdbc.utils.JDBCUtils;
public class JDBCDemo3 {
@Test
// 保存记录
public void demo1(){
Connection conn = null;
Statement stmt = null;
try{
// 获得连接:
conn = JDBCUtils.getConnection();
// 创建执行SQL语句的对象
stmt = conn.createStatement();
// 编写SQL:
String sql = "insert into user values (null,'ggg','123','小六')";
// 执行SQL:
int num = stmt.executeUpdate(sql);
if(num > 0){
System.out.println("保存成功!");
}
}catch(Exception e){
e.printStackTrace();
}finally{
// 释放资源:
JDBCUtils.release(stmt, conn);
}
}
}