Question

我实际上是在android应用中的数据库上工作（使用android studio）。我坚持这个错误说：

java.lang.NoSuchMethodError: No virtual method group(Ljava/lang/String;)Ljava/lang/String; in class Ljava/util/regex/Matcher; or its super classes (declaration of 'java.util.regex.Matcher' appears in /system/framework/core-libart.jar)

Full error logs

所以，问题是，我的代码可以编译，我可以编译所有内容，但是当我执行此部分时，它将关闭我的应用程序。由于Java / android studio中的DB是我的新手，所以我将为您提供所有技巧。

老实说，我不明白我该怎么做...

这是我使用并在代码中调用的类：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MySQLConnector {
    private static final String url = "jdbc:mysql://localhost:3306/mydb";
    private static final String user = "root";
    private static final String password = "password";

    private  Connection con;
    private  Statement stmt;
    private  ResultSet rs;

    public MySQLConnector() throws SQLException {
        try { 
            Class.forName("com.mysql.cj.jdbc.Driver").newInstance();
            con = DriverManager.getConnection(url, user, password);
            stmt = con.createStatement();

        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    void sendUpdate(String req) throws SQLException {
        stmt.executeUpdate(req);
        System.out.println("Command executed");

    }
    public void sendRequest(String req) throws SQLException {
        rs = stmt.executeQuery(req);
        System.out.println("Command executed");

    }
}

这是我的代码中的一个使用示例：

public class Check extends AppCompatActivity {
    private Button finApp ;
    private Intent intent;
    private String sessionID;
    private MySQLConnector connector;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_check);
        intent = getIntent();
        sessionID = intent.getStringExtra("SessionID");
        System.out.println("oncreatebutton");
        finApp=findViewById(R.id.button);
        try {
            connector = new MySQLConnector();
            connector.sendRequest("Select * from users");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        finApp.setOnClickListener(v -> {
            try {
                connector.sendUpdate("INSERT INTO users (first_name,last_name," +
                        "date_created,is_admin,num_points) VALUES('name','lastname',now(),0,6)");
            } catch (SQLException e) {
                e.printStackTrace();
            }
            System.out.println("test");

            System.out.println("Session id is :" + sessionID);
            finish();
        });
    }
}

connector = new MySQLConnector();
connector.sendRequest("Select * from users");

是失败的人

非常感谢任何尝试提供帮助的人。

java.lang.NoSuchMethodError：与虚拟方法组（Ljava / lang / String;）没有JDBC相关

0 个答案: