mysql连接数据库操作User对象

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1.新建一个User.java

package com.jzm.javabean;

import java.io.Serializable;
public class User implements Serializable {
private String name;
private String password;
private String sex;
private String email;
private String power;

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPower() {
return power;
}
public void setPower(String power) {
this.power = power;
}
}

2. 再建一个Conn_DB.java

package com.jzm.javabean;
import java.io.PrintWriter;
import java.sql.*;
public class ConnDB {
private static String driverName ="com.mysql.jdbc.Driver";
private static String userName ="root";
private static String usrPassword ="6056067";
private static String url = "jdbc:mysql://localhost/"+"video"+
"?user="+userName + "&password="+ usrPassword +
"&useUnicode=true&characterEncoding=gb2312";
private static Connection conn= null;
private static Statement sm = null;
private static PrintWriter out= null;

public static Connection getConn(){
   try {
            Class.forName(driverName).newInstance();
            conn = DriverManager.getConnection(url);
            sm = conn.createStatement();
   } catch (Exception e) {
   e.printStackTrace();
         out.print("数据库连接失败");
  }
   return conn;
}
public void CloseDb()
{
  try {
   if(sm != null)
   {
    sm.close();
   }
   conn.close();
  } catch (Exception e) {
    e.printStackTrace();
    out.print("数据库关闭失败");
  }
}

}

3. 建立一个操作user的类 DB_User.java

package com.jzm.javabean;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Vector;
public class DB_User {
private User user;
private ConnDB connDB;

public DB_User(ConnDB connDB)            //构造方法可以连接数据库
     {
     this.connDB = connDB;
     }

public User getUser(String username)
{
String sql = null;
ResultSet rSet = null;
Connection conn = null;
try {
     conn = ConnDB.getConn();
Statement sm = conn.createStatement();
sql = "select * from tb_user where name='"+
username+"'";
sql = new String(sql.getBytes("ISO8859-1"),"GB2312");
rSet = sm.executeQuery(sql);
if(rSet.next())
{
   user = new User();
   user.setName(rSet.getString("name"));
   user.setPassword(rSet.getString("password"));
   user.setSex(rSet.getString("sex"));
   user.setEmail(rSet.getString("email"));
   user.setPower(rSet.getString("power"));
   return user;
}
  return user;
} catch (Exception e) {
  e.printStackTrace();
  return null;
}finally{
     connDB.CloseDb();
}
}

public boolean addUser(User user)                       //增加用户
    {
String sql =null;
   try {
    Connection conn = ConnDB.getConn();
    Statement sm = conn.createStatement();
          sql = "insert into tb_user values('"+user.getName()
          +"','" + user.getPassword()+ "','"+user.getSex()+"','"
          +user.getEmail()+"','"+user.getPower()+"')";
          sql = new String(sql.getBytes("ISO8859-1"),"GB2312");
          sm.executeUpdate(sql);
} catch (Exception e) {
   e.printStackTrace();
   return false;
} finally{
  connDB.CloseDb();
}
        return true;
    }


public boolean deleteUser(String username)                        //删除用户
{
  String sql = null;
  Connection conn = null;
  try {
      conn = ConnDB.getConn();
   Statement sm = conn.createStatement();
   sql = "delete from tb_user where name='"+
   username+"'";
  int i = sm.executeUpdate(sql);
  if(i>=0){
   System.out.println("删除用户成功");
   return true;
  }else return false;
  }catch (Exception e) {
   e.printStackTrace();
   return false;
  }finally{
   connDB.CloseDb();
  }
}

public boolean updateUser(User user)                      //修改用户信息
{
boolean flag = false;
String sql = null;
Connection conn = null;
try {
     conn = ConnDB.getConn();
Statement sm = conn.createStatement();
sql = "update tb_user set password='"
   + user.getPassword() + "',sex='"
   + user.getSex() + "',email='"
   + user.getEmail()+ "',power='"
   + user.getPower()+ "' where name='"
   + user.getName()+ "'";
sql = new String(sql.getBytes("ISO8859-1"),"GB2312");
int i = sm.executeUpdate(sql);
System.out.println("i=="+i);
if(i >=0){
    return true;
}
}catch (Exception e) {
   e.printStackTrace();
   return false;
}finally{
  connDB.CloseDb();
}
return flag;
}

public Vector<User> getAllUsers()               //得到所有用户信息
{
   ResultSet rSet = null;
   Connection conn = null;
   Vector<User>vector =null;
  try {
      conn = ConnDB.getConn();
   Statement sm = conn.createStatement();
   rSet = sm.executeQuery("select * from tb_user");
   vector = new Vector<User>();
while(rSet.next()){
  User user = new User();
  String name = rSet.getString(1);
  String password = rSet.getString(2);
  String sex = rSet.getString(3);
  String email = rSet.getString(4);
  String power = rSet.getString(5);
  user.setName(name);
  user.setPassword(password);
  user.setEmail(email);
  user.setSex(sex);
  user.setPower(power);
  vector.add(user);
   }
     return vector;
  }catch (Exception e) {
   e.printStackTrace();
   System.out.println("查询所有用户失败！");
  } finally{
   connDB.CloseDb();
  }
  return vector;
}
}