1.预编译
创建数据库day0528和表t_user
CREATE DATABASE day0528;
USE day0528;
CREATE TABLE t_user(
id INT PRIMARY KEY AUTO_INCREMENT,
NAME VARCHAR(40),
PASSWORD VARCHAR(40),
email VARCHAR(40),
birthday DATE
);
INSERT INTO t_user(NAME,PASSWORD,email,birthday) VALUES('小龙女','16','[email protected]','2001-1-1');
INSERT INTO t_user(NAME,PASSWORD,email,birthday) VALUES('姬如雪','17','[email protected]','2002-2-2');
INSERT INTO t_user(NAME,PASSWORD,email,birthday) VALUES('女帝','18','[email protected]','2003-3-3');
SELECT * FROM t_user;
User.java
package zh.jdbc.demo;
import java.util.Date;
public class User {
private Integer id;
private String name;
private String password;
private String email;
private Date birthday;// java.util.Date
public User() {
}
public User(Integer id, String name, String password, String email,
Date birthday) {
super();
this.id = id;
this.name = name;
this.password = password;
this.email = email;
this.birthday = birthday;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
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 getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", password=" + password
+ ", email=" + email + ", birthday=" + birthday + "]";
}
}
JDBCUtils.java
package zh.jdbc.demo;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JDBCUtils {
private JDBCUtils() {
}
// 获取数据库连接
public static Connection getConnection(String driverClassName, String url,
String username, String password) {
try {
Class.forName(driverClassName);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Connection connection = null;
try {
connection = DriverManager.getConnection(url, username, password);
return connection;
} catch (SQLException cause) {
throw new RuntimeException("获取数据库连接失败", cause);
}
}
// 关闭资源
public static void close(Statement statement, Connection connection) {
if (statement != null) {
try {
statement.close();
} catch (SQLException cause) {
throw new RuntimeException("关闭Statement失败", cause);
}
statement = null;
}
if (connection != null) {
try {
connection.close();
} catch (SQLException cause) {
throw new RuntimeException("关闭数据库连接失败", cause);
}
}
connection = null;
}
// 关闭资源
public static void close(ResultSet resultSet, Statement statement,
Connection connection) {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException cause) {
throw new RuntimeException("关闭ResultSet失败", cause);
}
}
resultSet = null;
close(statement, connection);
}
}
UserDao.java
package zh.jdbc.demo;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class UserDao {
public UserDao() {
}
private String driverClassName = "com.mysql.jdbc.Driver";
private String url = "jdbc:mysql://localhost:3306/day0528";
private String username = "root";
private String password = "zh1277718668";
// 增加
public boolean insert(User user) {
Connection connection = null;
PreparedStatement pstatement = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String updateSQL = "insert into t_user(name,password,email,birthday) values(?,?,?,?)";
pstatement = connection.prepareStatement(updateSQL);
pstatement.setString(1, user.getName());
pstatement.setString(2, user.getPassword());
pstatement.setString(3, user.getEmail());
Date birthday = user.getBirthday();// // java.util.Date
pstatement.setDate(4, new java.sql.Date(birthday.getTime()));
int insertNum = pstatement.executeUpdate();
if (insertNum > 0) {
return true;
} else {
return false;
}
} catch (Exception cause) {
throw new RuntimeException("插入数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
// 删除
public boolean delete(int id) {
Connection connection = null;
PreparedStatement pstatement = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String deleteSQL = "delete from t_user where id = ?";
pstatement = connection.prepareStatement(deleteSQL);
pstatement.setInt(1, id);
int deleteNum = pstatement.executeUpdate();
if (deleteNum > 0) {
return true;
} else {
return false;
}
} catch (Exception cause) {
throw new RuntimeException("删除数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
// 修改
public boolean update(User user) {
Connection connection = null;
PreparedStatement pstatement = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String updateSQL = "update t_user set name =?,password=?,email=?,birthday=? where id=?";
pstatement = connection.prepareStatement(updateSQL);
pstatement.setString(1, user.getName());
pstatement.setString(2, user.getPassword());
pstatement.setString(3, user.getEmail());
pstatement.setDate(4, new java.sql.Date(user.getBirthday()
.getTime()));
pstatement.setInt(5, user.getId());
int updateNum = pstatement.executeUpdate();
if (updateNum > 0) {
return true;
} else {
return false;
}
} catch (Exception cause) {
throw new RuntimeException("修改数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
// 根据id查询
public User load(int id) {
User user = null;
Connection connection = null;
PreparedStatement pstatement = null;
ResultSet resultSet = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String querySQL = "select * from t_user where id = ?";
pstatement = connection.prepareStatement(querySQL);
pstatement.setInt(1, id);
resultSet = pstatement.executeQuery();
user = new User();
resultSet.next();// 光标默认在第一行之前，因此这里要下移一行
user.setId(resultSet.getInt("id"));
user.setName(resultSet.getString("name"));
user.setPassword(resultSet.getString("password"));
user.setEmail(resultSet.getString("email"));
// java.util.Date 是 java.sql.Date 的父类
user.setBirthday(resultSet.getDate("birthday"));
return user;
} catch (Exception cause) {
throw new RuntimeException("查询失败", cause);
} finally {
JDBCUtils.close(resultSet, pstatement, connection);
}
}
// 查询所有
public List<User> findAll() {
List<User> userList = null;
Connection connection = null;
PreparedStatement pstatement = null;
ResultSet resultSet = null;
try {
userList = new ArrayList<User>();
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String querySQL = "select * from t_user";
pstatement = connection.prepareCall(querySQL);
resultSet = pstatement.executeQuery();
while (resultSet.next()) {
User user = new User();
user.setId(resultSet.getInt("id"));
user.setName(resultSet.getString("name"));
user.setPassword(resultSet.getString("password"));
user.setEmail(resultSet.getString("email"));
// java.util.Date 是 java.sql.Date 的父类
user.setBirthday(resultSet.getDate("birthday"));
userList.add(user);
}
return userList;
} catch (Exception cause) {
throw new RuntimeException("查询失败", cause);
} finally {
JDBCUtils.close(resultSet, pstatement, connection);
}
}
}
UserDao.java
package zh.jdbc.demo;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import org.junit.Test;
public class UserDaoDemo {
@Test
public void insert() {
/**
* 添加user
*/
UserDao userDao = new UserDao();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
Date birthday = null;
try {
birthday = dateFormat.parse("2004-4-4");
} catch (ParseException e) {
e.printStackTrace();
}
User user = new User(5, "李逍遥", "19", "[email protected]", birthday);
boolean insert = userDao.insert(user);
System.out.println(insert);
}
@Test
public void delete() {
/**
* 根据id删除user
*/
UserDao userDao = new UserDao();
boolean delete = userDao.delete(4);
System.out.println(delete);
}
@Test
public void update() {
/**
* 修改user
*/
UserDao userDao = new UserDao();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
Date birthday = null;
try {
birthday = dateFormat.parse("2001-11-11");
} catch (ParseException e) {
e.printStackTrace();
}
User user = new User(1, "神仙姐姐", "18", "[email protected]", birthday);
boolean update = userDao.update(user);
System.out.println(update);
}
@Test
public void load() {
/**
* 根据id查询user
*/
UserDao userDao = new UserDao();
for (int i = 1; i <= 3; i++) {
User user = userDao.load(i);
System.out.println(user);
}
// User [id=1, name=神仙姐姐, password=18, [email protected], birthday=2001-11-11]
// User [id=2, name=姬如雪, password=17, [email protected], birthday=2002-02-02]
// User [id=3, name=女帝, password=18, [email protected], birthday=2003-03-03]
}
@Test
public void findAll() {
/**
* 查询所有user
*/
UserDao userDao = new UserDao();
List<User> userList = userDao.findAll();
System.out.println(userList);
// [User [id=1, name=神仙姐姐, password=18, [email protected], birthday=2001-11-11],
// User [id=2, name=姬如雪, password=17, [email protected], birthday=2002-02-02],
// User [id=3, name=女帝, password=18, [email protected], birthday=2003-03-03]]
}
}
insert结果：
delete结果：
update结果：
2.批处理
（1）Statement批处理
package zh.jdbc.demo;
import java.sql.Connection;
import java.sql.Statement;
import java.util.Arrays;
/**
* Statement批处理
*
* @author ZH
*
*/
public class BatchDemo1 {
public static void main(String[] args) {
String driverClassName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day0528";
String username = "root";
String password = "zh1277718668";
Connection connection = null;
Statement statement = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
statement = connection.createStatement();
String sql1 = "insert into t_user(name,password,email,birthday) values('赵灵儿','19','[email protected]','2004-4-4')";
String sql2 = "insert into t_user(name,password,email,birthday) values('龙葵','20','[email protected]','2005-5-5')";
String sql3 = "insert into t_user(name,password,email,birthday) values('小仙女','21','[email protected]','2006-6-6')";
statement.addBatch(sql1);
statement.addBatch(sql2);
statement.addBatch(sql3);
int[] nums = statement.executeBatch();
System.out.println(Arrays.toString(nums));//[1, 1, 1]
} catch (Exception cause) {
throw new RuntimeException("插入数据失败", cause);
} finally {
JDBCUtils.close(statement, connection);
}
}
}
结果：
（2）PreparedStatement批处理
package zh.jdbc.demo;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.Arrays;
/**
* PreparedStatement批处理
*
* @author ZH
*
*/
public class BatchDemo2 {
public static void main(String[] args) {
String driverClassName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day0528";
String username = "root";
String password = "zh1277718668";
Connection connection = null;
PreparedStatement pstatement = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String deleteSQL = "delete from t_user where id= ?";
pstatement = connection.prepareStatement(deleteSQL);
for (int id = 3; id <= 5; id++) {
pstatement.setInt(1, id);
pstatement.addBatch();
}
int[] nums = pstatement.executeBatch();
System.out.println(Arrays.toString(nums));//[1, 1, 1]
} catch (Exception cause) {
throw new RuntimeException("删除数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
}
结果：
3.大数据处理
（1）CLOB数据处理：文本数据
CREATE TABLE t_clob( id INT PRIMARY KEY AUTO_INCREMENT, readme TEXT ); SELECT * FROM t_clob;
【存数据】
package zh.jdbc.demo;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.Reader;
import java.sql.Connection;
import java.sql.PreparedStatement;
/**
* 存CLOB数据：文本数据
*
* @author ZH
*
*/
public class CLOBDemo1 {
public static void main(String[] args) {
String driverClassName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day0528";
String username = "root";
String password = "zh1277718668";
Connection connection = null;
PreparedStatement pstatement = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String insertSQl = "insert into t_clob(readme) values(?)";
pstatement = connection.prepareStatement(insertSQl);
Reader reader = new BufferedReader(new FileReader(
"F:/day0528//a.txt"));
pstatement.setClob(1, reader);
int num = pstatement.executeUpdate();
System.out.println(num);
} catch (Exception cause) {
throw new RuntimeException("插入数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
}
结果：
【取数据】
package zh.jdbc.demo;
import java.io.BufferedReader;
import java.io.Reader;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
/**
* 取CLOB数据：文本数据
*
* @author ZH
*
*/
public class CLOBDemo2 {
public static void main(String[] args) {
String driverClassName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day0528";
String username = "root";
String password = "zh1277718668";
Connection connection = null;
PreparedStatement pstatement = null;
ResultSet resultSet = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String querySQl = "select * from t_clob where id = ?";
pstatement = connection.prepareStatement(querySQl);
pstatement.setInt(1, 1);
resultSet = pstatement.executeQuery();
resultSet.next();
Clob clob = resultSet.getClob("readme");
Reader reader = clob.getCharacterStream();
BufferedReader bReader = new BufferedReader(reader);
String line = null;
while ((line = bReader.readLine()) != null) {
System.out.println(line);
}
// 静夜思
// 李白
// 床前明月光，
// 疑是地上霜。
// 举头望明月，
// 低头思故乡。
} catch (Exception cause) {
throw new RuntimeException("插入数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
}
（2）BLOB数据处理：二进制数据
CREATE TABLE t_blob( id INT PRIMARY KEY AUTO_INCREMENT, picture BLOB ); SELECT * FROM t_blob;
【存数据】
package zh.jdbc.demo;
import java.io.FileInputStream;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
/**
* 存BLOB数据：二进制数据
*
* @author ZH
*
*/
public class BLOBDemo1 {
public static void main(String[] args) {
String driverClassName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day0528";
String username = "root";
String password = "zh1277718668";
Connection connection = null;
PreparedStatement pstatement = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String insertSQl = "insert into t_blob(picture) values(?)";
pstatement = connection.prepareStatement(insertSQl);
InputStream inputStream = new FileInputStream(
"F://day0528//lyf.jpg");
pstatement.setBlob(1, inputStream);
int num = pstatement.executeUpdate();
System.out.println(num);//1
} catch (Exception cause) {
throw new RuntimeException("插入数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
}
结果：
【取数据】
package zh.jdbc.demo;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
/**
* 取BLOB数据：二进制数据
*
* @author ZH
*
*/
public class BLOBDemo2 {
public static void main(String[] args) {
String driverClassName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day0528";
String username = "root";
String password = "zh1277718668";
Connection connection = null;
PreparedStatement pstatement = null;
ResultSet resultSet = null;
try {
connection = JDBCUtils.getConnection(driverClassName, url,
username, password);
String querySQl = "select * from t_blob where id = ?";
pstatement = connection.prepareStatement(querySQl);
pstatement.setInt(1, 1);
resultSet = pstatement.executeQuery();
resultSet.next();
Blob blob = resultSet.getBlob("picture");
InputStream in = blob.getBinaryStream();
OutputStream out = new FileOutputStream("F://day0528//神仙姐姐.jpg");
byte[] buff = new byte[1024];
int len = 0;
while ((len = in.read(buff)) != -1) {
out.write(buff, 0, len);
}
out.flush();
out.close();
in.close();
} catch (Exception cause) {
throw new RuntimeException("插入数据失败", cause);
} finally {
JDBCUtils.close(pstatement, connection);
}
}
}
结果：
