Using GWT with mysql

Question

I am new to GWT. I am trying to connect to it with mysql server.

Below is my project hierarchy:

The name of the project hello, and the name of the package com.hello. By default, GWT creates 3 folders that

• com.hello.client
• com.hello.server
• com.hello.shared

The main java file containing the entry point for GWT is located in the com.hello.client folder named hello.java

I created the db_conn class (the file name is db_conn.java), which contains all the necessary code to connect to the mysql database. This file is placed in a folder com.hello.server. Below is the code

package com.hello.server;

import java.sql.Connection;
import java.sql.DriverManager;

public class db_conn 
{
    public Connection con;

    public db_conn()
    {

    }

    public String ConnectToDB()
    {
        try
        {
            String host          = "localhost";
            String db           = "test";
            String driver       = "com.mysql.jdbc.Driver";
            String user         = "root";
            String pass         = "pwd";

            Class.forName(driver).newInstance();
            con = DriverManager.getConnection(host+db, user, pass);

            return "Connected to Database";
        }
        catch(Exception ex)
        {
            return ex.toString();
        }

    }
}

In the hello.java file (which is located in the com.hello.client folder and contains the main entry point for GWT), I imported the class above import com.hello.server.*;

ConnectToDB() db_conn onModuleLoad() hello.java, :

com.hello.server.db_conn can not be found in source packages. Check the inheritance chain from your module; it may not be inheriting a required module or a module may not be adding its source path entries properly.

db_conn, , . . , .

Answer 1

, GWT JavaScript.

import com.hello.server. *

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• ( JavaScript)

  ///HelloService.java
  ///HelloServiceAsync.java

• RPC, ( JavaScript)

  ///HelloModel.java

• , HelloService HelloModel ( MySQL).

  ///HelloServiceImpl.java

Answer 2

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Answer 3

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Answer 4

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• , Eclipse IDE, , GWT, , , , "TICK OFF" Google APPLICATION - Google KIT ( , - ).

• / ( ), , jar SQL. :

  go to: WAR → WEBINF → lib → insert the SQL connector files inside lib, this will solve the class not found.