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数据库JAVA源代码百度 java操作数据库代码
Java源代码注释
你的这段代码是获取配置文件中数据库配置信息
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配置内容都在DBConfig.txt 这个文件中了
package dda;
import java.sql.*;
import java.io.LineNumberReader;
import java.io.FileReader;
import java.util.StringTokenizer;
/**
*
* 读取配置文件DBConfig.txt中的配置信息
* @author xxx
* @version 1.0
*/
public class DbConnection {
Connection conn = null;
ResultSet rs = null;
boolean b;
public DbConnection() {
this.b = false;
this.getDBConfig();
}
/* 定义变量 */
String strSeparate = " ";
String strFileName = "DBConfig.txt";
String strUserID = null;
String strUserPWD = null;
String strDB = null;
public void getDBConfig() {
this.getDBConfig();
try {
LineNumberReader oLineNumberReader = new LineNumberReader(
new FileReader(this.strFileName)); // 从 DBConfig.txt 文件中读取数据库配置
String strLine = null;
while ((strLine = oLineNumberReader.readLine()) != null) {// 遍历配置文件中每一行数据
StringTokenizer token = new StringTokenizer(strLine,(new String(this.strSeparate).toString())); // 按空格拆分配置内容
/* 以下三行都是给属性设值，获取配置属性 */
this.strDB = token.nextToken();
this.strUserID = token.nextToken();
this.strUserPWD = token.nextToken();
}
} catch (Exception e) {
System.out.println("DB:"+strFileName);
}
}
}
java程序操作MySQL数据库
数据库内容
java源代码 （代码实现的是查询成绩为 的人员信息 至于其他功能的 代码中有注释） 注意 在eclipse里运行程序的时候 要工程里插入jar包 否则运行异常！ import java sql *; import java io *; class database_manage { public Connection conn = null; public ResultSet rs = null; private String DatabaseDriver = " mysql jdbc Driver"; // DataSource 数据源名称DSN private String DatabaseConnStr = "jdbc:mysql://localhost: /people_manage?useUnicode=truecharacterEncoding=utf " + " root root"; public void setDatabaseDriver(String Driver) { this DatabaseDriver = Driver; } public String getDatabaseDriver() { return (this DatabaseDriver); } public void setDatabaseConnStr(String ConnStr) { this DatabaseConnStr = ConnStr; } public String getDatabaseConnStr() { return (this DatabaseConnStr); } public database_manage() {// 构造函数连接数据库 try { Class forName(DatabaseDriver); } catch (java lang ClassNotFoundException e) { System err println("加载驱动器有错误:" + e getMessage()); System out print("执行插入有错误:" + e getMessage());// 输出到客户端 } } public ResultSet query(String sql) {// 查询数据库 rs = null; try { conn = DriverManager getConnection( "jdbc:mysql://localhost: /people_manage?useUnicode=truecharacterEncoding=utf " "root" "root"); Statement stmt = conn createStatement(); rs = stmt executeQuery(sql); } catch (SQLException ex) { System err println("执行查询有错误:" + ex getMessage()); System out print("执行查询有错误:" + ex getMessage()); // 输出到客户端 }
return rs;
} public int update_database(String sql) {// 更新或插入数据库 int num = ; try { conn = DriverManager getConnection( "jdbc:mysql://localhost: /people_manage?useUnicode=truecharacterEncoding=utf " "root" "root"); Statement stmt = conn createStatement(); num = stmt executeUpdate(sql); } catch (SQLException ex) { System err println("执行插入有错误:" + ex getMessage()); System out print("执行插入有错误:" + ex getMessage());// 输出到客户端 } CloseDataBase(); return num; } public void CloseDataBase() {// 关闭数据库 try { conn close(); } catch (Exception end) { System err println("执行关闭Connection对象有错误 " + end getMessage()); System out print("执行执行关闭Connection对象有错误 有错误:" + end getMessage()); // 输出到客户端 } } } class people { private String uid; private String name; private String banji; private int score; public people() { } public people(String uid String name String banji) { this uid = uid; this name = name; this banji = banji; } public people(String uid String name String banji int score) { this uid = uid; this name = name; this banji = banji; this score = score; } public String getUid() { return uid; } public void setUid(String uid) { this uid = uid; } public String getName() { return name; } public void setName(String name) { this name = name; } public String getBanji() { return banji; } public void setBanji(String banji) { this banji = banji; } public int getScore() { return score; } public void setScore(int score) { this score = score; } } public class manage { private people[] people_array ;// 对象数组 public void add_people(String uid String name) { String sql = "insert people (uid name) values ( " + uid + " " + name + " )";// sql插入语句 // String sql = "insert people (uid name) values ( uid tom )"; database_manage db_obj = new database_manage(); db_obj update_database(sql); } public void update_people(String uid String name) { String sql = "update people set name= " + name + " where uid= " + uid + " "; database_manage db_obj = new database_manage(); db_obj update_database(sql); } public void delete_people(String uid) { String sql = "delete from people where uid= " + uid + " "; database_manage db_obj = new database_manage(); db_obj update_database(sql); } public people query_people(String uid) { database_manage db_obj = new database_manage(); // String adminid=null; String uid_new name banji; uid_new = null; name = null; banji = null; String sql_query = "select * from people where uid= " + uid + " "; try { ResultSet rs = db_obj query(sql_query); if (rs next()) { uid_new = rs getString("uid"); name = rs getString("name"); banji = rs getString("banji"); } } catch (Exception e) { e getMessage(); } people new_people = new people(uid_new name banji); return new_people; } public people[] query_people_byscore(int score) { database_manage db_obj = new database_manage(); String uid_new name banji; uid_new = null; name = null; banji = null; int score_new = ;
String sql_query = "select * from people where score=" + score;// sql查询语句
try {
ResultSet rs = db_obj query(sql_query);// 查询后 返回结果集
int num = ;
ResultSet rs_new = rs;
while (rs_new next()) {// 统计结果集中学生个数
num++;
}
// System out println(num);
people_array = new people[num];
int i = ;
rs beforeFirst();// 返回结果集的开始
while (rs next()) {
uid_new = rs getString("uid");
name = rs getString("name");
banji = rs getString("banji");
score_new = rs getInt("score");
people_array [i] = new people(uid_new name banji score_new);
i++;
}
} catch (Exception e) {
e getMessage();
}
return people_array ;
}
public static void main(String args[]) {
/*
* people new_people=new people();
*
* manage mr=new manage(); //mr add_people(" " "小明");插入一个学生的信息
*
* new_people=mr query_people(" ");//查询uid= 的学生信息 返回对象 System out
* println(""+new_people getName()+" "+new_people getBanji());
* mr update_people(" " "小王");更新一个学生的信息
*
* new_people=mr query_people(" ");//更新后查询
*
* System out println(""+new_people getName()+" "+new_people getBanji(
* ));
*/
manage mr = new manage();
// mr delete_people(" ");删除uid= 的学生信息
people[] people_array;// 声明对象数组
people_array = mr query_people_byscore( );// 返回成绩为一百的学生类数组 后输出
int num = ;
num = people_array length;
for (int i = ; i num; i++) {
System out println(people_array[i] getUid() + " "
+ people_array[i] getName() + " "
+ people_array[i] getBanji() + " "
+ people_array[i] getScore());
}
}
}
lishixinzhi/Article/program/Java/JSP/201311/20030
求一个简单又经典的JAVA数据库连接的例子,要有源代码哦!
我就弄的用户登入的代码吧.这个挺简单的.
这是题目:
用户登陆验证：
1.创建数据库Test，并新建用户表users
字段包含：username varchar(20) not null
userpwd varchar(20) not null
在JBUILDER中编写Long类，实现登陆界面，并在用户输入用户名和密码后，
完成按纽的单击事件，对用户输入的数据进行验证，
（需要严整数据是否为空，密码长度必须是15位）,
并实现与数据库的连接，将用户输入的用户名密码与表中的记录比较，
若用户名正确且密码正确，弹出提示框告知登陆成功，否则登陆失败。
这是代码:
//连接数据库
boolean isLogin(String name,String pwd){
boolean flag=false;
Connection conn=null;
PreparedStatement pst=null;
ResultSet rs=null;
//加载驱动
try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
//连接数据库
try {
conn=DriverManager.getConnection("jdbc:odbc:login");
String sql="select * from [user] where username=? and userpwd=?";
pst=conn.prepareStatement(sql);
pst.setString(1,name);
pst.setString(2,pwd);
rs=pst.executeQuery();
if(rs.next())
flag=true;
} catch (Exception ex) {
ex.printStackTrace();
}finally{
try {
conn.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
return flag;
}
//验证方法
public void jButton1_actionPerformed(ActionEvent e) {
String name=jTextField1.getText();
String pwd=jTextField2.getText();
//错误处理
if(name.equals("")||pwd.equals(""))
JOptionPane.showMessageDialog(this,"请输入完整的信息");
else {
if(isLogin(name,pwd))
JOptionPane.showMessageDialog(this,"登陆成功");
else
JOptionPane.showMessageDialog(this,"用户名或密码错误");
}
}
}
.....
.....
这是在事件里写的,
(高分)急求连接数据库的JAVA学生信息管理系统源代码
你要连的数据库是SQL 还是ORACLE
但是代码都查不多
下面的是连接SQL数据库的代码
你需要先创建个数据库,还有表,表的字段是登陆名和密码
下面的"SA" 是登陆名 "111111" 是密码
ORACLE 和这个查不多
import java.sql.*;//做数据库时候必须要引入的包
import com.microsoft.jdbc.sqlserver.SQLServerDriver;
public class DBFactory {
Connection Conn=null;
PreparedStatement Stmt=null;
ResultSet Rs=null;
String driverName="com.microsoft.jdbc.sqlserver.SQLServerDriver";
String OracleUserName="sa";
String OracleUserPwd="111111";
String ConnUrl="jdbc:sqlserver://localhost:1433;databaseName=news";
public Connection getConnection()
{
try {
Class.forName(driverName);
} catch (ClassNotFoundException ex) {
System.out.println("加载驱动程序有错误");
}
try {
Conn = DriverManager.getConnection(ConnUrl, OracleUserName,OracleUserPwd);
} catch (SQLException ex1) {
System.out.print("取得连接的时候有错误，请核对用户名和密码");
}
return Conn;
}
这个是连接ORACLE数据库代码
import java.sql.*;
import oracle.jdbc.driver.OracleDriver;
public class DBFactory {
Connection Conn=null;
PreparedStatement Stmt=null;
ResultSet Rs=null;
String driverName="oracle.jdbc.driver.OracleDriver";
String OracleUserName="scott";
String OracleUserPwd="tiger";
String ConnUr1="jdbc:oracle:thin:@locahost:1521:Ora";
public Connection getConnection()
{
try {
Class.forName(driverName);
} catch (ClassNotFoundException ex) {
System.out.println("加载驱动程序有错误");
}
try {
Conn = DriverManager.getConnection(ConnUr1, OracleUserName,OracleUserPwd);
} catch (SQLException ex1) {
System.out.print("取得连接时有错误，请核对用户名和密码");
}
return Conn;
}
希望能追加分数谢谢！
求JAVA源代码
我用了半个小时 帮你写了一个简单的验证用户名和密码登陆问题 别辜负我的好意 下面是代码!（建好包和类 代码粘过去就能用）
实体类 包entity
-------------------------------------------------------------
package entity;
/**
* 用户实体类
* @author new
*
*/
public class Users {
private String name;//用户名
private String pass;//用户密码
/**
* 空的构造函数 用户实力化 此类对象
*/
public Users(){
}
/**
* 构造函数 接收用户名和密码
* @param name
* @param pass
*/
public Users(String name, String pass) {
this.name = name;
this.pass = pass;
}
/**
* 下面set和get方法就不用解释了吧
* @return
*/
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPass() {
return pass;
}
public void setPass(String pass) {
this.pass = pass;
}
}
数据库类 包dao(我是模拟一下数据库 没有用到数据库)
--------------------------------------------------------------
package dao;
import java.util.*;
import entity.Users;//导入实体类
/**
* 模拟数据库 用户DAO
* @author new
*
*/
public class UsersDAO {
private static Users users=new Users();
static
{
users.setName("tom");
users.setPass("jerry");
}
/**
* 根据姓名查找这个用户 (模拟一下数据库)
* @param name
* @return
*/
public Users findUserByName(String name)
{
if(name.equals(this.users.getName()))
{
return this.users;
}
return null;
}
}
业务类 包service (验证用户名和密码)
------------------------------------------------------------
package service;
import dao.UsersDAO;
import entity.Users;
/**
* 验证密码 业务类
* @author new
*
*/
public class validatePass {
//实力化DAO对象
private UsersDAO us=new UsersDAO();
/**
* 验证输入的密码是否正确
* @param name
* @param pass
* @return
*/
public Users validate(String name,String pass)
{
Users user=null;
user=us.findUserByName(name);
//如果不为空 说明查到了
if(user!=null)
{
//用查询出来对象的密码和传过来的密码比较
if(user.getPass().equals(pass))
{
return user;
}
}
return null;
}
}
最后是测试test类 包test
----------------------------------------------------------
package test;
import entity.Users;
import service.validatePass;
/**
* 测试类
* @author new
*
*/
public class test {
/**
* main方法 用于测试
* @param args
*/
public static void main(String[] args)
{
//实例化业务类对象
validatePass v=new validatePass();
//用户名和密码
String name="tom";
String pass="jerry";
//开始验证
Users user=v.validate(name, pass);
if(user==null)
{
System.out.println("你输入的用户名或密码错误!");
}else
{
System.out.println("你已经通过验证，成功登陆!");
}
}
}
java连接数据库的代码
package mysql;
import java.sql.*;
/**
* @author xys
*/
public class ConnectMysql {
public static Connection getConnection() throws ClassNotFoundException, SQLException {
String url = "jdbc:mysql://localhost:3306/databaseName";
String user = "mysqluser";
String password = "password";
String driverClass = "com.mysql.cj.jdbc.Driver";
Connection connection = null;
Class.forName(driverClass);
try {
connection = DriverManager.getConnection(url, user, password);
} catch (SQLException e) {
e.printStackTrace();
}
if (connection != null) {
System.out.println("数据库连接成功");
} else {
System.out.println("数据库连接失败");
connection.close();
}
return connection;
}
public void getResult() throws ClassNotFoundException, SQLException {
// 实例化 Statement 对象
Statement statement = getConnection().createStatement();
// 要执行的 Mysql 数据库操作语句（增、删、改、查）
String sql = "";
// 展开结果集数据库
ResultSet resultSet = statement.executeQuery(sql);
while (resultSet.next()) {
// 通过字段检索
int id = resultSet.getInt("id");
String name = resultSet.getString("name");
// 输出数据
System.out.println("ID : " +id);
System.out.println("name :" + name);
}
// 完成后需要依次关闭
resultSet.close();
statement.close();
getConnection().close();
}
}
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