Java使用jdbc连接MySQL数据库详细实例

MySQL数据库：

首先，我们需要在Mysql的test数据库下新建一个table，比如如下student表：



该表的create语句如下：

CREATE TABLE `student` (
`sno` int(11) NOT NULL,
`sname` varchar(20) NOT NULL,
`sex` varchar(1) DEFAULT NULL,
`birthday` date DEFAULT NULL,
`email` varchar(20) DEFAULT NULL,
`addr` varchar(20) DEFAULT NULL,
PRIMARY KEY (`sno`)
)

注意：请在操作之前自行插入测试数据。
Java代码：

0. 添加MySQL驱动jar到项目路径（点此下载驱动jar）

1. 在org.plyy.utils包下建DBManager类，该类的作用是管理新建和关闭数据库连接：

package org.plyy.utils;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBManager {

private static Connection conn = null;

private static final String DB_USER = "root";	//数据库用户名
private static final String DB_PASS = "test123";	//用户密码
private static final String DB_URL = "jdbc:mysql://localhost:3306/test";//数据库对应url
private static final String DB_DRIVER = "com.mysql.jdbc.Driver";	//数据库驱动

/*建立数据库连接，返回连接对象*/
public static Connection getConnection(){

try {
Class.forName(DB_DRIVER);	//装载数据库驱动程序
System.out.println("Success loading Mysql Driver!");
conn = DriverManager.getConnection(DB_URL,DB_USER,DB_PASS);	//建立连接，获取连接对象
System.out.println("Success connect Mysql server!");
}
catch (ClassNotFoundException e) {
System.out.println("Error loading Mysql Driver!");
e.printStackTrace();
}
catch (SQLException e) {
System.out.println("Error connect Mysql server!");
e.printStackTrace();
}

return conn;
}

/*关闭连接*/
public static void closeAll(Connection conn, PreparedStatement stmt, ResultSet rs){

try {
if(rs != null){
rs.close();
}
if(stmt != null){
stmt.close();
}
if(conn != null){
conn.close();
}
} catch (SQLException e) {
System.out.println("Error close connection!");
e.printStackTrace();
}
}

}

2. 在org.plyy.entity包下建Student类，该类的作用是关联数据库中的student表，将数据库的数据对应到Java实体：

package org.plyy.entity;

import java.sql.Date;

public class Student {

private int sno;
private	String sname;
private	char sex;
private	Date birthday;
private String email;
private String addr;

public Student(int sno, String sname, char sex, Date birthday,
String email, String addr) {
super();
this.sno = sno;
this.sname = sname;
this.sex = sex;
this.birthday = birthday;
this.email = email;
this.addr = addr;
}

@Override
public String toString() {
return  sno + "\t" + sname + "\t" + sex
+ "\t" + birthday + "\t" + email + "\t"
+ addr;
}

public int getSno() {
return sno;
}

public void setSno(int sno) {
this.sno = sno;
}

public String getSname() {
return sname;
}

public void setSname(String sname) {
this.sname = sname;
}

public char getSex() {
return sex;
}

public void setSex(char sex) {
this.sex = sex;
}

public Date getBirthday() {
return birthday;
}

public void setBirthday(Date birthday) {
this.birthday = birthday;
}

public String getEmail() {
return email;
}

public void setEmail(String email) {
this.email = email;
}

public String getAddr() {
return addr;
}

public void setAddr(String addr) {
this.addr = addr;
}

}

3. 在org.plyy.dao包下建IStudentDao接口，该接口的作用是定义各种数据操作方法：

package org.plyy.dao;

import java.util.List;

import org.plyy.entity.Student;

public interface IStudentDao {

List<Student> getAllStudent();	//获得student表中的数据

}

4. 在org.plyy.dao.impl包下建StudentDaoImpl类，该类的作用是实现dao下定义的各种数据操作方法：

package org.plyy.dao.impl;

import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import org.plyy.dao.IStudentDao;
import org.plyy.entity.Student;
import org.plyy.utils.DBManager;

public class StudentDaoImpl implements IStudentDao{

private Connection conn = null;
private PreparedStatement ptst = null;
private ResultSet rs = null;

@Override
public List<Student> getAllStudent() {

List<Student> list = new ArrayList<Student>();

conn = DBManager.getConnection();

String sql = "select * from student";

try {
ptst = conn.prepareStatement(sql);
rs = ptst.executeQuery();

Student stu = null;

while(rs.next()){
int sno = rs.getInt("sno");
String sname = rs.getString("sname");
char sex = rs.getString("sex").charAt(0);
Date birthday = rs.getDate("birthday");
String email = rs.getString("email");
String addr = rs.getString("addr");
stu = new Student(sno,sname,sex,birthday,email,addr);
list.add(stu);
}
}
catch (SQLException e) {
System.out.println("Error execute sql statement!");
e.printStackTrace();
}
finally{
DBManager.closeAll(conn,ptst,rs);
}
return list;
}

5. 在org.plyy.test包下建test类，完成测试：

package org.plyy.test;

import java.util.ArrayList;
import java.util.List;

import org.plyy.dao.IStudentDao;
import org.plyy.dao.impl.StudentDaoImpl;
import org.plyy.entity.Student;

public class Test {

public static void main(String[] args) {

List<Student>  l_test = new ArrayList<Student>();

IStudentDao test = new StudentDaoImpl();
l_test = test.getAllStudent();

System.out.println("sno\tsname\t\tsex\tbirthday\temail\t\taddr");
for (Student stu : l_test) {
System.out.println(stu);
}
}

}

至此结束。

有任何问题请咨询王萌(puliuyinyi@qq.com)