jdbc连接数据库，并封装成数据库工具类
import java.io.BufferedOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Properties;
import java.util.Vector;
import server.bean.Book;
public class DBTools {
private static String driver;
private static String url;
private static String user;
private static String password;
private static InputStream is;
private static Connection conn;
static {
Properties pt = new Properties();
is = DBTools.class.getClassLoader().getResourceAsStream("jdbc.properties");
try {
pt.load(is);
driver = pt.getProperty("driver");
url = pt.getProperty("url");
user = pt.getProperty("user");
password = pt.getProperty("password");
IOUtils.close(is);
} catch (IOException e) {
IOUtils.close(is);
log("/n读取数据库配置文件失败/n " + e);
}
}
// log
public static void log(String str) {
DateFormat df = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String time = df.format(System.currentTimeMillis());
str = time + " " + str;
FileOutputStream fos = null;
BufferedOutputStream bos = null;
try {
fos = new FileOutputStream("DBErroLog.txt");
bos = new BufferedOutputStream(fos);
byte[] b = str.getBytes();
bos.write(b);
bos.flush();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
IOUtils.close(fos, bos);
}
}
// 获取连接
public static Connection getConnection() {
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, user, password);
return conn;
} catch (ClassNotFoundException e) {
log("加载驱动失败，没有找到类！！！\n" + e);
} catch (SQLException e) {
e.printStackTrace();
log("数据库连接失败，请检查ip地址，端口号,账号及密码是否有误！！！\n" + e);
}
return null;
}
// 登录验证 SELECT NAME,pwd,is_manager FROM usr WHERE NAME='tan' AND
// pwd='123456';
public static int loginCheck(String usr, String pwd) throws SQLException {
String sql = " SELECT is_manager FROM usr WHERE name=? AND pwd=?;";
PreparedStatement ps = getConnection().prepareStatement(sql);
ps.setString(1, usr);
ps.setString(2, pwd);
ResultSet rs = ps.executeQuery();
// 判断账号密码是否正确
if (rs.next()) {
// 判断是管理员还是学生
if (rs.getBoolean(1)) {
close();
return 1;
} else {
close();
return 0;
}
}
close();
return -1;
}
// 改密码
public static boolean changePwd(String usr, String pwd) {
String sql = " UPDATE usr SET pwd=? WHERE NAME=?;";
PreparedStatement ps;
try {
ps = getConnection().prepareStatement(sql);
ps.setString(1, pwd);
ps.setString(2, usr);
int n = ps.executeUpdate();
System.out.println(n);
if (n > 0) {
close();
return true;
}
} catch (SQLException e) {
}
close();
return false;
}
// 按id查询书籍
public static Vector selectByid(String book_id) throws SQLException {
// SELECT book_id,book_name,book_info,book_total FROM book WHERE
// book_id='1111';
Vector books = null;
String sql = "SELECT book_id,book_name,book_info,book_total,book_num FROM book WHERE book_id=?";
PreparedStatement ps = getConnection().prepareStatement(sql);
ps.setString(1, book_id);
ResultSet rs = ps.executeQuery();
while (rs.next()) {
if (books == null) {
books = new Vector();
}
Book book = new Book();
String id = rs.getString(1);
String name = rs.getString(2);
String info = rs.getString(3);
int total = rs.getInt(4);
int num = rs.getInt(5);
book.setBook_id(id);
book.setBook_name(name);
book.setBook_info(info);
book.setBook_total(total);
book.setBook_num(num);
books.add(book);
}
close();
return books;
}
// 按名字匹配书籍
public static Vector selectByName(String book_name) throws SQLException {
// SELECT book_id,book_name,book_info,book_total FROM book WHERE
// book_name LIKE '%编程%';
Vector books = null;
String sql = " SELECT book_id,book_name,book_info,book_total,book_num FROM book WHERE book_name LIKE ?";
PreparedStatement ps = getConnection().prepareStatement(sql);
ps.setString(1, "%" + book_name + "%");
ResultSet rs = ps.executeQuery();
while (rs.next()) {
if (books == null) {
books = new Vector();
}
Book book = new Book();
String id = rs.getString(1);
String name = rs.getString(2);
String info = rs.getString(3);
int total = rs.getInt(4);
int num = rs.getInt(5);
book.setBook_id(id);
book.setBook_name(name);
book.setBook_info(info);
book.setBook_total(total);
book.setBook_num(num);
books.add(book);
}
close();
return books;
}
// 添加书籍
public static boolean addBook(String bookId, String bookName, String bookInfo, int bookTotal, int bookNum) {
String sql = "insert book values(?,?,?,?,?);";
PreparedStatement ps;
try {
ps = getConnection().prepareStatement(sql);
ps.setString(1, bookId);
ps.setString(2, bookName);
ps.setString(3, bookInfo);
ps.setInt(4, bookTotal);
ps.setInt(5, bookNum);
int n = ps.executeUpdate();
System.out.println(n);
if (n > 0) {
close();
return true;
}
} catch (SQLException e) {
}
close();
return false;
}
// 批量删除书籍DELETE FROM book WHERE book_id='123';
public static boolean deleteBooks(String[] array) {
String sql = "DELETE FROM book WHERE book_id=?;";
PreparedStatement ps;
int n = 0;
try {
ps = getConnection().prepareStatement(sql);
for (String string : array) {
ps.setString(1, string);
n += ps.executeUpdate();
}
} catch (SQLException e) {
}
if (n > 0) {
return true;
} else {
return false;
}
}
// 修改书籍UPDATE book SET
// book_name='java编程',book_info='java编程思想',book_total='20',book_num='20'
// WHERE book_id='23d3';
public static boolean updateBook(Book book) {
if (book == null) {
return false;
}
String sql = "UPDATE book SET book_name=?,book_info=?,book_total=?,book_num=? WHERE book_id=?;";
PreparedStatement ps;
int n = 0;
try {
ps = getConnection().prepareStatement(sql);
ps.setString(1, book.getBook_name());
ps.setString(2, book.getBook_info());
ps.setInt(3, book.getBook_total());
ps.setInt(4, book.getBook_num());
ps.setString(5, book.getBook_id());
n = ps.executeUpdate();
} catch (SQLException e) {
}
if (n > 0) {
return true;
} else {
return false;
}
}
// 关闭连接
public static void close() {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
log("数据库连接关闭失败\n" + e);
}
}
}
public static void main(String[] args) throws SQLException {// 测试
/*
* String sql = "select * from usr;";
* try {
* PreparedStatement ps = getConnection().prepareStatement(sql);
* ResultSet rs = ps.executeQuery();
* while (rs.next()) {
* System.out.println(rs.getString(1));
* System.out.println(rs.getString(2));
* }
* } catch (SQLException e) {
*
* e.printStackTrace();
* }
*/
// changePwd("tan", "123");
// Vector books = selectByid("1111");
// System.out.println(books.size());
// Vector books1 = selectByName("编程");
// System.out.println(books1.size());
// addBook("123456789", "c语音", "c语言详解", 10, 5);
String[] str = { "233", "5" };
System.out.println(deleteBooks(str));
}
}
