/**
* 数据库访问操作类
*/
package php-note.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
public class DBAccess {
// 数据库驱动
private String drv = "com.mysql.jdbc.Driver";
// 连接URL
private String url = "jdbc:mysql://localhost:3306/php-note";
// 用户名
private String usr= "root";
// 密码
private String pwd = "110";
// 数据库连接对象
private Connection conn = null;
// 数据库声明对象
private Statement stm = null;
// 数据结果集对象
private ResultSet rs = null;
/**
* @return the drv
*/
public String getDrv() {
return drv;
}
/**
* @param drv the drv to set
*/
public void setDrv(String drv) {
this.drv = drv;
}
/**
* @return the url
*/
public String getUrl() {
return url;
}
/**
* @param url the url to set
*/
public void setUrl(String url) {
this.url = url;
}
/**
* @return the usr
*/
public String getUsr() {
return usr;
}
/**
* @param usr the usr to set
*/
public void setUsr(String usr) {
this.usr = usr;
}
/**
* @return the pwd
*/
public String getPwd() {
return pwd;
}
/**
* @param pwd the pwd to set
*/
public void setPwd(String pwd) {
this.pwd = pwd;
}
/**
* @return the conn
*/
public Connection getConn() {
return conn;
}
/**
* @param conn the conn to set
*/
public void setConn(Connection conn) {
this.conn = conn;
}
/**
* @return the stm
*/
public Statement getStm() {
return stm;
}
/**
* @param stm the stm to set
*/
public void setStm(Statement stm) {
this.stm = stm;
}
/**
* @return the rs
*/
public ResultSet getRs() {
return rs;
}
/**
* @param rs the rs to set
*/
public void setRs(ResultSet rs) {
this.rs = rs;
}
/**
* 创建连接对象
* @return
*/
public boolean createConn() {
boolean b = false;
try {
Class.forName(drv).newInstance();
conn = DriverManager.getConnection(url, pwd, pwd);
} catch(SQLException e) {
} catch (ClassNotFoundException e) {
} catch (InstantiationException e) {
} catch (IllegalAccessException e) {
}
return b;
}
/**
* 更新SQL函数
*/
public boolean update(String sql) {
boolean b = false;
try {
stm = conn.createStatement();
stm.execute(sql);
b = true;
} catch(Exception e) {
}
return b;
}
/**
* 查询SQL函数
*/
public void query(String sql) {
try {
stm = conn.createStatement();
rs = stm.executeQuery(sql);
} catch (Exception e) {
}
}
/**
* 移到下一条记录函数
*/
public boolean next() {
boolean b = false;
try {
if (rs.next()) {
b = true;
}
} catch(Exception e) {
}
return b;
}
/**
* 获取字段field的值
*/
public String getValue(String field) {
String value = null;
try {
if (rs != null) {
value = rs.getString(field);
}
} catch(Exception e) {
}
return value;
}
/**
* 关闭结果集对象RS
*/
public void closeRs() {
try {
if (rs != null) {
rs.close();
}
} catch(SQLException e) {
}
}
/**
* 关闭申明对象stm
*/
public void closeStm() {
try {
if (stm != null) {
stm.close();
}
} catch(SQLException e) {
}
}
/**
* 关闭数据库连接对象
*/
public void closeConn() {
try {
if (conn != null) {
conn.close();
}
} catch(SQLException e) {
}
}
}
应用示例：
UserBean.java
package php-note.tools;
import php-note.util.DBAccess;
public class UserBean {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.print("yes");
}
/**
* 验证用户名与密码
*/
public boolean valid(String username, String password) {
boolean isValid = false;
DBAccess db = new DBAccess();
if (db.createConn()) {
String sql = "select * from user where username='" + username + "' and password='" + password + "'";
db.query(sql);
if (db.next()) {
isValid = true;
}
db.closeRs();
db.closeStm();
db.closeConn();
}
return isValid;
}
/**
* 检查用户名是否存在
*/
public boolean isExist(String username) {
boolean isExist = false;
DBAccess db = new DBAccess();
if (db.createConn()) {
String sql = "select * from user where username='" + username + "'";
db.query(sql);
if (db.next()) {
isExist = true;
}
db.closeRs();
db.closeStm();
db.closeConn();
}
return isExist;
}
/**
* 添加用户
* @param String username 用户名
* @param String password 用户密码
* @param String email 用户Email
*/
public void add(String username, String password, String email) {
DBAccess db = new DBAccess();
if (db.createConn()) {
String sql = "insert into user(`username`,`password`,`email`) values ('" + username + "','" + password + "','" + email + "')";
db.update(sql);
db.closeStm();
db.closeConn();
}
}
}