JDBC 利用propertise简单例子
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2022-03-24 09:02:30
1、db.propertise文件driver=com.mysql.jdbc.Driverurl=jdbc:mysql://localhost:3306/schoolusername=rootpassword=1234562、JdbcUtil类文件package JDBC_Test;import java.io.IOException;import java.io.InputStream;import java.sql.*;import java.util.Pro......
1、db.propertise文件
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/school
username=root
password=123456
2、JdbcUtil类文件
package JDBC_Test;
import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;
public class JdbcUtils {
private static String strDriver = null;
private static String strUrl = null;
private static String strUserName = null;
private static String strPassword = null;
static{
try {
InputStream in = JdbcUtils.class.getClassLoader().getResourceAsStream("db.properties");
Properties properties = new Properties();
properties.load(in);
strDriver = properties.getProperty("driver");
strUrl = properties.getProperty("url");
strUserName = properties.getProperty("username");
strPassword = properties.getProperty("password");
Class.forName(strDriver);
} catch (Exception e) {
e.printStackTrace();
}
}
//获取连接
public static Connection getConnection() throws SQLException {
return DriverManager.getConnection(strUrl, strUserName, strPassword);
}
//释放资源
public static void release(Connection conn, Statement state, ResultSet rs){
if(null != rs){
try {
rs.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
if(null != state){
try {
state.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
if(null != conn){
try {
conn.close();
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
}
}
3、测试类
package JDBC_Test;
import com.sun.scenario.effect.impl.sw.java.JSWBlend_SRC_OUTPeer;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import static JDBC_Test.JdbcUtils.*;
public class demo2 {
public static void main(String[] args) {
Connection connection = null;
Statement statement = null;
ResultSet resultSet = null;
try {
connection = JdbcUtils.getConnection();//获取连接
statement = connection.createStatement();
//?useUnicode=true&characterEncoding=utf8&useSSL=true
//增加语句
String strInsertSql = "INSERT INTO student(`studentno`, `loginpwd`,`studentname`,`sex`,`gradeid`,`phone`,`address`,`borndate`,`email`,`identitycard`)\n" +
"VALUES(1009,'123456','ke',1,3,'123456789','金华','1994-12-16','2123456@qq.com','1324546878454')";
//删除语句
String strDeleteSql = "DELETE FROM student WHERE `studentname`='aaa';";
//更新语句
string strUpdateSql = "UPDATE student \n" +
"SET `studentname`='bbb', `sex`=1\n" +
"WHERE `studentno`=1009 \n";
//查询语句
String strQuerySql = "SELECT * FROM student \n" +
"WHERE `studentname`='ke'";
int iRow = statement.executeUpdate(strInsertSql);
if (iRow > 0) {
System.out.println("插入成功");
}
bbb
resultSet = statement.executeQuery(strQuerySql);
while (resultSet.next()) {
System.out.println("id= " + resultSet.getObject("studentno"));
System.out.println("name= " + resultSet.getObject("studentname"));
System.out.println("sex= " + resultSet.getObject("sex"));
System.out.println("gradeid= " + resultSet.getObject("gradeid"));
System.out.println("phone= " + resultSet.getObject("phone"));
}
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
JdbcUtils.release(connection, statement, resultSet);
}
}
}
JDBC事务操作
package JDBC_Test;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class JDBC_TransAction {
public static void main(String[] args) {
Connection connection = null;
PreparedStatement preSt = null;
ResultSet resultSet = null;
try {
connection = JdbcUtils.getConnection();
connection.setAutoCommit(false);//取消自动提交 并且开始事务
String strSql1 = "UPDATE bank SET money=money + 100 WHERE `name`='A';";
preSt = connection.prepareStatement(strSql1);
int iRow1 = preSt.executeUpdate();
if(iRow1 <= 0){
System.out.println("strSql1执行失败,iRow1:" + iRow1);
}
String strSql2 = "UPDATE bank SET money=money - 100 WHERE `name`='B'";
preSt = connection.prepareStatement(strSql2);
int iRow2 = preSt.executeUpdate();
if(iRow2 <= 0){
System.out.println("strSql2执行失败,iRow2:" + iRow2);
}
connection.commit();
System.out.println("转账成功");
String strSelect = "select * from bank";
preSt = connection.prepareStatement(strSelect);
resultSet = preSt.executeQuery();
while (resultSet.next()){
System.out.println("name: " + resultSet.getObject("name") + "money: " + resultSet.getObject("money"));
}
} catch (SQLException throwables) {
throwables.printStackTrace();
try {
connection.rollback();
} catch (SQLException e) {
e.printStackTrace();
}
}finally {
try {
connection.setAutoCommit(true);
} catch (SQLException throwables) {
throwables.printStackTrace();
}
JdbcUtils.release(connection,preSt,resultSet);
}
}
}
JDBC_PerpareStatement 安全的方法(防止注入攻击)
package JDBC_Test; import java.sql.*; import java.util.Date; public class JDBC_PerpareStatement { public static void main(String[] args) { Connection connection = null; PreparedStatement preparedStatement = null; ResultSet resultSet = null; try { connection = JdbcUtils.getConnection(); String strInsertSql = "INSERT INTO result(`studentno`,`subjectno`,`examdate`,`studentresult`) VALUES(?,?,?,?)"; preparedStatement = connection.prepareStatement(strInsertSql); preparedStatement.setInt(1, 1006); preparedStatement.setInt(2, 3); preparedStatement.setDate(3, new java.sql.Date(new Date().getTime())); preparedStatement.setInt(4, 77); int iRow = preparedStatement.executeUpdate(); if(iRow > 0){ System.out.println("perpareStatement mysql 执行成功!"); } } catch (SQLException throwables) { throwables.printStackTrace(); }finally { JdbcUtils.release(connection, preparedStatement, resultSet); } } }
本文地址:https://blog.csdn.net/qq_34600513/article/details/110999954