android studio mysql database using JDBC access (Kotlin method)

Tools: mysql-connector-java-5.1.48.jar, mysql version 5.6.19, android studio built simulator

1.connection

import java.sql.DriverManager

interface Connection {
     fun init(){
        var driver="com.mysql.jdbc.Driver"
        var url="jdbc:mysql://10.0.2.2:3306/test"
        var user="root"
        var psd="rs123456"
        try {
            Class.forName(driver).newInstance()
            println ( "a successful connection 1" )
        }catch (e:Exception){
            e.printStackTrace ()
            println ( "Connection failed" )
        }

        try{
            Thread({
                DriverManager.getConnection(url,user,psd)
                println ( "a successful connection 2" )
            }).start()

        }catch (e:Exception) {
            e.printStackTrace ()
            the println ( "connection failed 2" )
        }

    }
}

View Code

Note: android studio built simulator must be set to the ip address 10.0.2.2

Reference https://blog.csdn.net/qq_37141773/article/details/84326163 connection problems

2.PreparedStatement

【Ready to work】

In the data table to establish the test

 use test;

create table stuinfo(id int,name varchar(20));

 

 <1>

import java.lang.Exception
import java.sql.Driver
import java.sql.DriverManager
import java.sql.PreparedStatement

interface Connection {
     fun init(){
        var driver="com.mysql.jdbc.Driver"
        var url="jdbc:mysql://10.0.2.2:3306/test"
        var user="root"
        var psd="rs123456"
        try {
            Class.forName(driver).newInstance()
            println ( "a successful connection 1" )
        }catch (e:Exception){
            e.printStackTrace ()
            println ( "Connection failed" )
        }

        try{
            Thread({
                val conn=DriverManager.getConnection(url,user,psd)

                var sql:String="insert into stuinfo(id,name)values(?,?)"
                val ps:PreparedStatement=conn.prepareStatement(sql)
                ps.setString(1,"3")
                ps.setString(2,"vocus")
                ps.execute()
            }).start()

        }catch (e:Exception) {
            e.printStackTrace ()
            the println ( "connection failed 2" )
        }

    }
}

 <2> Util class

class DbUtil {
    fun updateDatabase(sql:String,vararg args:Any) {
        var driver = "com.mysql.jdbc.Driver"
        var url = "jdbc:mysql://10.0.2.2:3306/test"
        var user = "root"
        var psd = "rs123456"

        //var sql = "insert into stuinfo(id,name) values(?,?)"
        try {
            Class.forName(driver).newInstance()
            println ( "Database connection was successful ..." )
        } catch (e: Exception) {
            e.printStackTrace ()
        }
        try {
            Thread({
                var conn = DriverManager.getConnection(url, user, psd)
                var ps = conn!!.prepareStatement(sql)
                for(i in 0 until args.size){
                    ps.setObject(i+1,args[i])
                }
                ps.execute()
                println ( "Operation successful data ..." )
            }).start()

        } catch (e: Exception) {
            e.printStackTrace ()
        }
    }
}