IDEA中使用properties连接mysql8.0.13

旧城等待， 2022-04-11 02:40 538阅读 0赞

### IDEA中使用properties连接mysql8.0.13 ###

1.IDEA下导入mysql-connector-java-8.0.13.jar,并添加到Modules中

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2.在项目下新建一个目录(Directory)，一般properties文件夹命名应为resoures

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjAzOTY5OQ_size_16_color_FFFFFF_t_70 1][]

3.右键新建的resources文件夹，选择Mark Dictory as >>Resources Root将文件夹定义为配置文件夹

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4.右键resources类型的文件夹选择Resource Bundle，就能创建properties文件了

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjAzOTY5OQ_size_16_color_FFFFFF_t_70 3][]

5.mysql8.0.13的properties文件内容为：

注意：配置文件是以键值对形式来进行存/读取的，一个对象占用一行，行末不能添加分号

driver=com.mysql.cj.jdbc.Driver
    url=jdbc:mysql://localhost:3306/goods?useSSL=false&serverTimezone=UTC
    username=root
    password=123456

![20181204130158231.png][]

6.properties使用的静态代码块有两种:

第一种：Properties

public static String driver;
        public static String url;
        public static String username;
        public static String password;
        static {
            Properties pt = new Properties();
            try{
                FileInputStream in = new FileInputStream("resources/db.properties");
                pt.load(in);
                driver = pt.getProperty("driver");
                url = pt.getProperty("url");
                username = pt.getProperty("username");
                password = pt.getProperty("password");
            }catch (IOException e){
                e.printStackTrace();
            }
        }

public static String driver;
        public static String url;
        public static String username;
        public static String password;
        static {
            try{
                ClassLoader classLoader = JDBCUtils.class.getClassLoader();
                InputStream is = classLoader.getResourceAsStream("db.properties");
                Properties pt = new Properties();
                pt.load(is);
                driver = pt.getProperty("driver");
                url = pt.getProperty("url");
                username = pt.getProperty("username");
                password = pt.getProperty("password");
            }catch (IOException e){
                e.printStackTrace();
            }
        }

第二种：ResourceBundle

private static String driver;
        private static String url;
        private static String username;
        private static String password;
        static{
            ResourceBundle bundle = ResourceBundle.getBundle("db");
            driver = bundle.getString("driver");
            url = bundle.getString("url");
            username = bundle.getString("username");
            password = bundle.getString("password");
        }

7.具体测试代码：

JDBCUtils.java

package pers.wpc.jdbc;
    
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.sql.*;
    import java.util.Properties;
    import java.util.ResourceBundle;
    
    public class JDBCUtils {
        public static String driver;
        public static String url;
        public static String username;
        public static String password;
        static {
            Properties pt = new Properties();
            try{
                FileInputStream in = new FileInputStream("resources/db.properties");
                pt.load(in);
                driver = pt.getProperty("driver");
                url = pt.getProperty("url");
                username = pt.getProperty("username");
                password = pt.getProperty("password");
            }catch (IOException e){
                e.printStackTrace();
            }
        }
        /**
        *Properties
        public static String driver;
        public static String url;
        public static String username;
        public static String password;
        static {
            try{
                ClassLoader classLoader = JDBCUtils.class.getClassLoader();
                InputStream is = classLoader.getResourceAsStream("db.properties");
                Properties pt = new Properties();
                pt.load(is);
                driver = pt.getProperty("driver");
                url = pt.getProperty("url");
                username = pt.getProperty("username");
                password = pt.getProperty("password");
            }catch (IOException e){
                e.printStackTrace();
            }
        }*/
        /**
        *ResourceBundle
        private static String driver;
        private static String url;
        private static String username;
        private static String password;
        static{
            ResourceBundle bundle = ResourceBundle.getBundle("db");
            driver = bundle.getString("driver");
            url = bundle.getString("url");
            username = bundle.getString("username");
            password = bundle.getString("password");
        }*/
        public static Connection getConnection(){
            Connection conn = null;
            try {
                Class.forName(driver);
                conn= DriverManager.getConnection(url,username,password);
            }catch (Exception e){
                e.printStackTrace();
            }
            return conn;
        }
        public static void release(Connection conn, PreparedStatement pstmt, ResultSet rs){
            if (rs!=null){
                try {
                    rs.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
            }
            if (pstmt!=null){
                try {
                    pstmt.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
            }
            if (conn!=null){
                try {
                    conn.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
            }
        }
    }

TestUtils.java

package pers.wpc.jdbc;
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    public class TestUtils {
        public static void main(String[] args) {
            Connection conn=null;
            PreparedStatement pstmt=null;
            ResultSet rs=null;
            try {
                conn =JDBCUtils.getConnection();
                String sql = "select * from t_book where bid=?";
                pstmt = conn.prepareStatement(sql);
                pstmt.setInt(1,2);
                rs = pstmt.executeQuery();
                while (rs.next()){
                    System.out.print(rs.getString(2)+"----"+rs.getString("author"));
                }
            }catch (SQLException e){
                e.printStackTrace();
            } finally {
                JDBCUtils.release(conn,pstmt,rs);
            }
        }
    }

[20181204131442100.png]: /images/20220411/a0416e1561154870ad9fad51ff19269c.png
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[20181204130158231.png]: /images/20220411/d656fce3761946c0976ac496762ce928.png