从一个类到另一个类的方法的依赖注入

Question

Suppose we have the following class, which defines three values:

public class DataForOperations {
    public static Serialization serialize = new Serialization();

    String user_id = serialize.serialization(new TypeRef<User>() {
    }).getUsername();
    int update_id = serialize.serialization(new TypeRef<Result>() {
    }).getUpdate_id();
    String user_message = serialize.serialization(new TypeRef<Message>() {
    }).getText();
}

Then now, in another class, I'd like to call this three values into a method:

public void InsertDataToDatabase(String user_id, String user_message, int update_id) throws SQLException {
    final Connection connection = DriverManager.getConnection(url, userlogin, password);
    try (Statement statement = connection.createStatement()) {
        statement.executeUpdate("INSERT INTO telegramapitest " + id + update_id + user_id + user_message, statement.RETURN_GENERATED_KEYS);
    }
}

How can i do this? I've read quite a few articles, but they all address dependencies in the same class.

Answer 1

Welcome HearthWarrio at stackoverflow!

I see three points here:

1. Dependency Injection (DI) is a different thing, you like to do old-school object-orientated-programming (OOP).

2. DataForOperations is a class having non-static fields. So in order to access theese 3 values you need to create an instance of the class DataForOperations. You can do this by using

   DataForOperations myObject = new DataForOperations(); AnotherClass anotherClassInstance = new AnotherClass(); anotherClassInstance.InsertDataToDatabase(myObject.user_id, myObject.user_message, myObject.update_id);

3. The syntax of the insert-statement is wrong. Do you need support for the correct syntax?