新手上路,弄了将近半天,实在是找不出问题在哪儿了,求大佬们拯救qwq我的开发环境是:8.0.11版本的mysql数据库
驱动:mysql-connector-java-8.0.11.jar
android stdio 3.2
运行时,控制台一直报如下错误:目录结构是这样:
MainActivity 内代码:package com.example.database_test;import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;public class MainActivity extends AppCompatActivity implements View.OnClickListener { @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); Button oBtn = (Button)findViewById(R.id.button_start);
oBtn.setOnClickListener(this); } @Override
public void onClick(View v) {
switch (v.getId()){
case R.id.button_start:
new Thread(new Runnable() {
@Override
public void run() {
try {
DaoTest.gets();
}catch (Exception e){
e.printStackTrace();
}
}
}).start();
break;
default:
break;
}
}
}DaoTest内代码:package com.example.database_test;
import android.util.Log;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class DaoTest { public static void gets() throws SQLException, ClassNotFoundException, InstantiationException, IllegalAccessException {
String driver = "com.mysql.cj.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day14";
String username="xxx";
String password="yyy";
//1:加载驱动
Class.forName(driver).newInstance();
//2:获取连接
Connection conn = DriverManager.getConnection(url,username,password); if(!conn.isClosed())
System.out.println("succeeded to connect database !"); //3:获取向数据库法sql语句的statement对象
Statement st = conn.createStatement(); //4:向数据库法sql语句,获取被封装成结果集的数据(ResultSet)
ResultSet rs = st.executeQuery("select * from users"); //5:从结果集对象中,获取数据
while(rs.next()){
Log.d("id=",(String)rs.getObject("id"));
Log.d("name=",(String)rs.getObject("name"));
Log.d("password=",(String)rs.getObject("password"));
Log.d("email=",(String)rs.getObject("email"));
Log.d("birthday=",(String)rs.getObject("birthday"));
}
//6:释放链接,以及其他资源
rs.close();
st.close();
conn.close(); }}
在 MainFest 里 ,也已经设置过网络权限了
新人实在是找不出问题在哪里了,跪求大佬拯救qwq
驱动:mysql-connector-java-8.0.11.jar
android stdio 3.2
运行时,控制台一直报如下错误:目录结构是这样:
MainActivity 内代码:package com.example.database_test;import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;public class MainActivity extends AppCompatActivity implements View.OnClickListener { @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main); Button oBtn = (Button)findViewById(R.id.button_start);
oBtn.setOnClickListener(this); } @Override
public void onClick(View v) {
switch (v.getId()){
case R.id.button_start:
new Thread(new Runnable() {
@Override
public void run() {
try {
DaoTest.gets();
}catch (Exception e){
e.printStackTrace();
}
}
}).start();
break;
default:
break;
}
}
}DaoTest内代码:package com.example.database_test;
import android.util.Log;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class DaoTest { public static void gets() throws SQLException, ClassNotFoundException, InstantiationException, IllegalAccessException {
String driver = "com.mysql.cj.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/day14";
String username="xxx";
String password="yyy";
//1:加载驱动
Class.forName(driver).newInstance();
//2:获取连接
Connection conn = DriverManager.getConnection(url,username,password); if(!conn.isClosed())
System.out.println("succeeded to connect database !"); //3:获取向数据库法sql语句的statement对象
Statement st = conn.createStatement(); //4:向数据库法sql语句,获取被封装成结果集的数据(ResultSet)
ResultSet rs = st.executeQuery("select * from users"); //5:从结果集对象中,获取数据
while(rs.next()){
Log.d("id=",(String)rs.getObject("id"));
Log.d("name=",(String)rs.getObject("name"));
Log.d("password=",(String)rs.getObject("password"));
Log.d("email=",(String)rs.getObject("email"));
Log.d("birthday=",(String)rs.getObject("birthday"));
}
//6:释放链接,以及其他资源
rs.close();
st.close();
conn.close(); }}
在 MainFest 里 ,也已经设置过网络权限了
新人实在是找不出问题在哪里了,跪求大佬拯救qwq
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注意你的连接地址。