You can call Java stored procedures from any PL/SQL block, subprogram, or package. For example, assume that the executable for the following Java class is stored in Oracle Database:

import java.sql.*;
import oracle.jdbc.*;

public class Adjuster
{
  public static void raiseSalary (int empNo, float percent) throws SQLException
  {
    Connection conn = DriverManager.getConnection("jdbc:default:connection:");
    String sql = "UPDATE employees SET salary = salary * ? WHERE employee_id = ?";
    try
    {
      PreparedStatement pstmt = conn.prepareStatement(sql);
      pstmt.setFloat(1, (1 + percent / 100));
      pstmt.setInt(2, empNo);
      pstmt.executeUpdate();
      pstmt.close();
    }
    catch (SQLException e)
    {
      System.err.println(e.getMessage());
    }
  }
}

The Adjuster class has one method, which raises the salary of an employee by a given percentage. Because raiseSalary() is a void method, you must publish it as a procedure, as follows:

CREATE OR REPLACE PROCEDURE raise_salary (empno NUMBER, pct NUMBER)
AS LANGUAGE JAVA
NAME 'Adjuster.raiseSalary(int, float)';

In the following example, you call the raise_salary procedure from an anonymous PL/SQL block:

DECLARE
emp_id NUMBER;
percent NUMBER;
BEGIN
-- get values for emp_id and percent
raise_salary(emp_id, percent);
...
END;

In the following example, you call the row_count function, which defined in Example 7-3, from a standalone PL/SQL stored procedure:

CREATE PROCEDURE calc_bonus (emp_id NUMBER, bonus OUT NUMBER) AS
emp_count NUMBER;
...
BEGIN
emp_count := row_count('employees');
...
END;

In the following example, you call the raise_sal method of the Employee object type, which is defined in "Implementing Object Type Methods", from an anonymous PL/SQL block:

DECLARE
emp_id NUMBER(4);
v emp_type;
BEGIN
-- assign a value to emp_id
SELECT VALUE(e) INTO v FROM emps e WHERE empno = emp_id;
v.raise_sal(500);
UPDATE emps e SET e = v WHERE empno = emp_id;
...
END;