一.下载jar包
下载oracle驱动包：ojdbc6.jar，放于如下位置：
测试代码：
package com.test;
import java.sql.Connection;
import java.sql.DriverManager;
import org.junit.Test;
public class Test01 {
@Test
public void test() {
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection conn = null;
//orcl 是数据库名；test123是用户名；qwer1234是密码
conn = DriverManager.getConnection(
"jdbc:oracle:thin:@localhost:1521:orcl", "test123",
"qwer1234");
} catch (Exception e) {
e.printStackTrace();
}
}
}
运行成功就算连接成功了，之后就可以操作数据库了。
参考地址：https://blog.csdn.net/he__xu/article/details/83410966
jar包下载链接：https://pan.baidu.com/s/1j2lV7uJWsgmW0yym9j8jHw 提取码：0mqk
二、使用spring框架：
1.需要下载：
commons-dbcp jar包：
下载地址：http://commons.apache.org/proper/commons-dbcp/download_dbcp.cgi
链接：https://pan.baidu.com/s/1BsbXz1FG4FQi4-ZSIWnYhQ 提取码：d3uo
commons-pool jar包：
下载地址：http://commons.apache.org/proper/commons-pool/download_pool.cgi
链接：https://pan.baidu.com/s/1LTK2WQ1CIsIglYqVZBr6ig 提取码：38v8
链接：https://pan.baidu.com/s/1O6cI7FOtlMYyzzYDX4phcQ 提取码：b3sn
2.web.xml配置：
<!--配置数据源 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"/>
<property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"/>
<property name="username" value="test123"/>
<property name="password" value="qwer1234"/>
<!-- 连接池启动时的初始值 -->
<property name="initialSize" value="3" />
<!-- 连接池的最大值 -->
<property name="maxActive" value="300" />
<!-- 最大空闲值.当经过一个高峰时间后，连接池可以慢慢将已经用不到的连接慢慢释放一部分，一直减少到maxIdle为止 -->
<property name="maxIdle" value="2" />
<!-- 最小空闲值.当空闲的连接数少于阀值时，连接池就会预申请去一些连接，以免洪峰来时来不及申请 -->
<property name="minIdle" value="1" />
<!-- end -->
</bean>
3.测试代码：
@Test
public void test() {
ApplicationContext ctx = new ClassPathXmlApplicationContext(
"resource/applicationContext.xml");
}
备注：如果有以下报错：
警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource': Failed to introspect bean class [org.apache.commons.dbcp.BasicDataSource] for lookup method metadata: could not find class that it depends on; nested exception is java.lang.NoClassDefFoundError: org/apache/commons/pool/ObjectPool
可以把commons-pool2-2.4.3.jar需要换成commons-pool-1.6.jar
三、调用测试：
代码：
public void test() {
ApplicationContext ctx = new ClassPathXmlApplicationContext("resource/applicationContext.xml");
BasicDataSource dataSource = (BasicDataSource) ctx.getBean("dataSource");
}
解决：在aop后面添加一个属性：proxy-target-class="true"
测试通过后直接试着调用一下
代码：
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
ApplicationContext ctx = new ClassPathXmlApplicationContext("resource/applicationContext.xml");
BasicDataSource dataSource = (BasicDataSource) ctx.getBean("dataSource");
String msg = "";
Statement st = null;
ResultSet rs = null;
try {
// 1、获取连接对象
Connection conn = dataSource.getConnection();
// 2、创建statement类对象，用来执行SQL语句！！
st = conn.createStatement();
// 3、创建sql查询语句
String sql = "select * from sys_user ";
// 4、执行sql语句并且换回一个查询的结果集
rs = st.executeQuery(sql);
while (rs.next()) { // 循环遍历结果集
int id = rs.getInt("user_id");
String name = rs.getString("real_name");
msg += "id=" + id + "--" + "name=" + name+"<br>";
}
} catch (SQLException e) {
e.printStackTrace();
}
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html><head><title>一二零叁的网站</title></head><body>");
out.print(msg);
out.print("</body></html>");
}
其中用户表：
结果：
四、使用配置文件
1.jdbc.properties:
jdbc.driver=oracle.jdbc.driver.OracleDriver
jdbc.url=jdbc:oracle:thin:@localhost:1521:orcl
jdbc.username=test123
jdbc.password=qwer1234
2.web.xml改为：
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list> <value>classpath:resource/jdbc.properties</value>
</list>
</property>
</bean>
<!--配置数据源 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
<!-- 连接池启动时的初始值 -->
<property name="initialSize" value="3" />
<!-- 连接池的最大值 -->
<property name="maxActive" value="300" />
<!-- 最大空闲值.当经过一个高峰时间后，连接池可以慢慢将已经用不到的连接慢慢释放一部分，一直减少到maxIdle为止 -->
<property name="maxIdle" value="2" />
<!-- 最小空闲值.当空闲的连接数少于阀值时，连接池就会预申请去一些连接，以免洪峰来时来不及申请 -->
<property name="minIdle" value="1" />
<!-- end -->
</bean>
这样就可以了。
五、简单的用户登录
1.登录界面login.jsp:
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>一二零叁的网站</title>
<script type="text/javascript">
function zhuce(){
alert("跳转到注册界面......");
}
</script>
</head>
<body>
<center>
<h1 style="color:#7D26CD">登录</h1>
<hr style="width:85%">
<form id="indexform" name="indexForm" action="logincheck.jsp"
method="post">
<table border="0">
<tr>
<td>账号：</td>
<td colspan="2"><input type="text" name="username">
</td>
</tr>
<tr>
<td>密码：</td>
<td colspan="2"><input type="password" name="password">
</td>
</tr>
<tr>
<td colspan="3" align="center">
<br>
<input type="submit" value="登录" style="color:#BC8F8F">
<input type="button" onclick="zhuce()" value="注册" style="color:#BC8F8F">
</td>
</tr>
</table>
</form>
</center>
</body>
</html>
2.登录验证：logincheck.jsp:
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="java.lang.*"%>
<%@ page import="com.service.Login"%>
<%@ page import="net.sf.json.JSONObject"%>
<%
try {
request.setCharacterEncoding("UTF-8");
String username = (String) request.getParameter("username");
String password = (String) request.getParameter("password");//取出login.jsp的值
Login login = new Login();
JSONObject loginResult = login.checkLogin(username, password);
if (1 == loginResult.getInt("status")) {
response.sendRedirect("../IndexServlet");
} else {
out.print("<script language='javaScript'> alert('"
+ loginResult.getString("msg") + "');</script>");
response.setHeader("refresh", "0;url=login.jsp");
}
} catch (Exception e) {
e.printStackTrace();
}
%>
3.用户验证Login.java:
package com.service;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import net.sf.json.JSONObject;
import org.apache.commons.dbcp.BasicDataSource;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Login {
public JSONObject checkLogin(String username,String password){
JSONObject result = new JSONObject();
ApplicationContext ctx = new ClassPathXmlApplicationContext("resource/applicationContext.xml");
BasicDataSource dataSource = (BasicDataSource) ctx.getBean("dataSource");
PreparedStatement ps =null;
try {
// 1、获取连接对象
Connection conn = dataSource.getConnection();
// 2、创建statement类对象，用来执行SQL语句！！
ps = conn.prepareStatement("select password,enabled from sys_user where user_name = ? ");
// 3、创建sql查询语句
ps.setString(1, username);
// 4、执行sql语句并且换回一个查询的结果集
ResultSet rs = ps.executeQuery();
if (rs.next()) { // 有查询结果
if(!password.equals(rs.getString("password"))){
result.put("status", "3");
result.put("msg", "密码错误");
} else if(1!=rs.getInt("enabled")){
result.put("status", "4");
result.put("msg", "改账号不允许登录");
} else {
result.put("status", "1");
result.put("msg", "允许登录");
}
} else {
result.put("status", "2");
result.put("msg", "不存在该账号");
}
} catch (SQLException e) {
e.printStackTrace();
}
return result;
}
}
4.结果：
登录界面:
登录失败：
登录成功：
