Example usage for java.lang Class forName

List of usage examples for java.lang Class forName

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Introduction

In this page you can find the example usage for java.lang Class forName.

Prototype

@CallerSensitive
public static Class<?> forName(String className) throws ClassNotFoundException

Source Link

Document

Returns the Class object associated with the class or interface with the given string name.

Usage

From source file:Main.java

public static void main(String[] args) throws Exception {
    Connection conn = null;//from  www.  j  a  v  a 2s . co  m
    Statement stmt = null;

    Class.forName(JDBC_DRIVER);
    conn = DriverManager.getConnection(DB_URL, USER, PASS);
    System.out.println("Deleting database...");
    stmt = conn.createStatement();

    conn = DriverManager.getConnection(DB_URL, USER, PASS);

    stmt = conn.createStatement();
    String sql = "SELECT id, first, last, age FROM Person";
    ResultSet rs = stmt.executeQuery(sql);
    while (rs.next()) {
        // Retrieve by column name
        int id = rs.getInt("id");
        int age = rs.getInt("age");
        String first = rs.getString("firstName");
        String last = rs.getString("lastName");

        // Display values
        System.out.print("ID: " + id);
        System.out.print(", Age: " + age);
        System.out.print(", First: " + first);
        System.out.println(", Last: " + last);
    }
    rs.close();
    stmt.close();
    conn.close();
}

From source file:Main.java

public static void main(String... args) {
    String argType = (args.length == 0 ? "" : args[0]);
    try {/*from w w w  .j  ava  2s .c  om*/
        Class<?> c = Class.forName("Main");
        if ("".equals(argType)) {
            // IllegalArgumentException: wrong number of arguments
            Object o = c.getConstructor().newInstance("foo");
        } else if ("int".equals(argType)) {
            // NoSuchMethodException - looking for int, have Integer
            Object o = c.getConstructor(int.class);
        } else if ("Object".equals(argType)) {
            // newInstance() does not perform method resolution
            Object o = c.getConstructor(Object.class).newInstance("foo");
        } else {
            assert false;
        }

        // production code should handle these exceptions more gracefully
    } catch (ClassNotFoundException x) {
        x.printStackTrace();
    } catch (NoSuchMethodException x) {
        x.printStackTrace();
    } catch (InvocationTargetException x) {
        x.printStackTrace();
    } catch (InstantiationException x) {
        x.printStackTrace();
    } catch (IllegalAccessException x) {
        x.printStackTrace();
    }
}

From source file:Main.java

public static void main(String[] args) throws Exception {
    Connection conn = null;/*from   w ww  . ja va2 s.  c  o  m*/
    Statement stmt = null;

    Class.forName(JDBC_DRIVER);
    conn = DriverManager.getConnection(DB_URL, USER, PASS);
    System.out.println("Deleting database...");
    stmt = conn.createStatement();

    conn = DriverManager.getConnection(DB_URL, USER, PASS);

    stmt = conn.createStatement();

    String sql = "UPDATE Registration SET age = 30 WHERE id in (1, 2)";
    stmt.executeUpdate(sql);

    sql = "SELECT id, first, last, age FROM Person";
    ResultSet rs = stmt.executeQuery(sql);
    while (rs.next()) {
        // Retrieve by column name
        int id = rs.getInt("id");
        int age = rs.getInt("age");
        String first = rs.getString("firstName");
        String last = rs.getString("lastName");

        // Display values
        System.out.print("ID: " + id);
        System.out.print(", Age: " + age);
        System.out.print(", First: " + first);
        System.out.println(", Last: " + last);
    }
    rs.close();
    stmt.close();
    conn.close();
}

From source file:Main.java

public static void main(String[] args) throws Exception {

    Class.forName(DRIVER);
    Connection connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);

    Statement statement = connection.createStatement();
    ResultSet resultSet = statement.executeQuery("SELECT * FROM users");

    ResultSetMetaData metadata = resultSet.getMetaData();
    int columnCount = metadata.getColumnCount();

    ArrayList<String> columns = new ArrayList<String>();
    for (int i = 1; i < columnCount; i++) {
        String columnName = metadata.getColumnName(i);
        columns.add(columnName);/*  w  w w .j av a  2 s .c o  m*/
    }

    while (resultSet.next()) {
        for (String columnName : columns) {
            String value = resultSet.getString(columnName);
            System.out.println(columnName + " = " + value);
        }
    }
}

From source file:Main.java

public static void main(String[] args) throws Exception {
    try {//  w w  w .  j  av a  2 s. c  o  m
        String url = "jdbc:odbc:databaseName";
        String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
        String user = "guest";
        String password = "guest";
        FileInputStream fis = new FileInputStream("somefile.txt");
        Class.forName(driver);
        Connection connection = DriverManager.getConnection(url, user, password);
        Statement createTable = connection.createStatement();

        createTable.executeUpdate("CREATE TABLE source_code (name CHAR(20), source LONGTEXT)");

        String ins = "INSERT INTO source_code VALUES(?,?)";
        PreparedStatement statement = connection.prepareStatement(ins);

        statement.setString(1, "TryInputStream"); // Set first field
        statement.setAsciiStream(2, fis, fis.available()); // Stream is source

        int rowsUpdated = statement.executeUpdate();
        System.out.println("Rows affected: " + rowsUpdated);
        connection.close();
    } catch (Exception e) {
        System.err.println(e);
    }
}

From source file:JavaDBDemo.java

public static void main(String[] args) {
    String driver = "org.apache.derby.jdbc.EmbeddedDriver";
    String connectionURL = "jdbc:derby:myDatabase;create=true";
    String createString = "CREATE TABLE Employee (NAME VARCHAR(32) NOT NULL, ADDRESS VARCHAR(50) NOT NULL)";
    try {//from www  . j a  v a2  s  .  co  m
        Class.forName(driver);
    } catch (java.lang.ClassNotFoundException e) {
        e.printStackTrace();
    }
    try {
        conn = DriverManager.getConnection(connectionURL);
        Statement stmt = conn.createStatement();
        stmt.executeUpdate(createString);

        PreparedStatement psInsert = conn.prepareStatement("insert into Employee values (?,?)");

        psInsert.setString(1, args[0]);
        psInsert.setString(2, args[1]);

        psInsert.executeUpdate();

        Statement stmt2 = conn.createStatement();
        ResultSet rs = stmt2.executeQuery("select * from Employee");
        int num = 0;
        while (rs.next()) {
            System.out.println(++num + ": Name: " + rs.getString(1) + "\n Address" + rs.getString(2));
        }
        rs.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

From source file:Main.java

public static void main(String[] args) {
    Connection conn = null;/*from w  ww . ja v  a 2  s.  c  o  m*/
    Statement stmt = null;
    try {
        Class.forName(JDBC_DRIVER);
        conn = DriverManager.getConnection(DB_URL, USER, PASS);
        stmt = conn.createStatement();
        String sql = "SELECT id, first, last, age FROM Employees";
        ResultSet rs = stmt.executeQuery(sql);
        while (rs.next()) {
            int id = rs.getInt("id");
            int age = rs.getInt("age");
            String first = rs.getString("first");
            String last = rs.getString("last");

            System.out.print("ID: " + id);
            System.out.print(", Age: " + age);
            System.out.print(", First: " + first);
            System.out.println(", Last: " + last);
        }
        rs.close();
        stmt.close();
        conn.close();
    } catch (SQLException se) {
        se.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            if (stmt != null)
                stmt.close();
            if (conn != null)
                conn.close();
        } catch (SQLException se) {
            se.printStackTrace();
        }
    }
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Connection dbConnection = null;
    PreparedStatement preparedStatement = null;
    Class.forName(DB_DRIVER);
    dbConnection = DriverManager.getConnection(DB_CONNECTION, DB_USER, DB_PASSWORD);
    String deleteSQL = "DELETE Person WHERE USER_ID = ?";
    preparedStatement = dbConnection.prepareStatement(deleteSQL);
    preparedStatement.setInt(1, 1001);/*from www . j av  a2  s. c o  m*/

    preparedStatement.executeUpdate();
    preparedStatement.close();
    dbConnection.close();

}

From source file:Select.java

public static void main(String args[]) {
    String url = "jdbc:msql://carthage.imaginary.com/ora";
    Connection con = null;/*from ww  w  .  j ava 2 s  .  c  o  m*/

    try {
        String driver = "com.imaginary.sql.msql.MsqlDriver";

        Class.forName(driver).newInstance();
    } catch (Exception e) {
        System.out.println("Failed to load mSQL driver.");
        return;
    }
    try {
        con = DriverManager.getConnection(url, "borg", "");
        Statement select = con.createStatement();
        ResultSet result = select.executeQuery("SELECT test_id, test_val FROM test");

        System.out.println("Got results:");
        while (result.next()) { // process results one row at a time
            int key = result.getInt(1);
            String val = result.getString(2);

            System.out.println("key = " + key);
            System.out.println("val = " + val);
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (con != null) {
            try {
                con.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    Connection dbConnection = null;
    PreparedStatement preparedStatement = null;
    Class.forName(DB_DRIVER);
    dbConnection = DriverManager.getConnection(DB_CONNECTION, DB_USER, DB_PASSWORD);
    String updateTableSQL = "UPDATE Person SET USERNAME = ? " + " WHERE USER_ID = ?";
    preparedStatement = dbConnection.prepareStatement(updateTableSQL);

    preparedStatement.setString(1, "newValue");
    preparedStatement.setInt(2, 1001);/*from  w  w w.  j  av  a2s .  c o  m*/

    preparedStatement.executeUpdate();

    preparedStatement.executeUpdate();
    preparedStatement.close();
    dbConnection.close();

}