feat: Add Account POJO and AccountHandler with JDBC connection and query methods

sql/java/Account.java

@@ -0,0 +1,73 @@
+/**
+ * Account POJO representing a row in the accounts table.
+ * Mirrors the COBOL ws-account-record structure.
+ */
+public class Account {
+
+    private int id;
+    private String firstName;
+    private String lastName;
+    private String phone;
+    private String address;
+    private String isEnabled;
+    private String createDt;
+    private String modDt;
+
+    public Account(int id, String firstName, String lastName, String phone,
+                   String address, String isEnabled, String createDt, String modDt) {
+        this.id = id;
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.phone = phone;
+        this.address = address;
+        this.isEnabled = isEnabled;
+        this.createDt = createDt;
+        this.modDt = modDt;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public String getPhone() {
+        return phone;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public String getIsEnabled() {
+        return isEnabled;
+    }
+
+    public String getCreateDt() {
+        return createDt;
+    }
+
+    public String getModDt() {
+        return modDt;
+    }
+
+    @Override
+    public String toString() {
+        return "Account{" +
+                "id=" + id +
+                ", firstName='" + firstName + '\'' +
+                ", lastName='" + lastName + '\'' +
+                ", phone='" + phone + '\'' +
+                ", address='" + address + '\'' +
+                ", isEnabled='" + isEnabled + '\'' +
+                ", createDt='" + createDt + '\'' +
+                ", modDt='" + modDt + '\'' +
+                '}';
+    }
+}

sql/java/AccountHandler.java

@@ -0,0 +1,164 @@
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Manages PostgreSQL JDBC connection and provides query methods
+ * for the accounts table. Mirrors the COBOL program's SQL operations.
+ */
+public class AccountHandler {
+
+    private static final String DB_URL = "jdbc:postgresql://localhost:5432/cobol_db_example";
+    private static final String DB_USER = "postgres";
+    private static final String DB_PASSWORD = "password";
+
+    private Connection connection;
+
+    /**
+     * Establishes a JDBC connection to the PostgreSQL database.
+     * On failure, prints SQL error details and exits.
+     */
+    public void connect() {
+        try {
+            connection = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
+            System.out.println("Connected to database.");
+        } catch (SQLException e) {
+            System.out.println("SQL Error:");
+            System.out.println("SQL State: " + e.getSQLState());
+            System.out.println("Error Code: " + e.getErrorCode());
+            System.out.println("Error Message: " + e.getMessage());
+            System.exit(1);
+        }
+    }
+
+    /**
+     * Closes the database connection if it is open.
+     */
+    public void disconnect() {
+        try {
+            if (connection != null && !connection.isClosed()) {
+                connection.close();
+                System.out.println("Disconnected.");
+            }
+        } catch (SQLException e) {
+            System.out.println("SQL Error:");
+            System.out.println("SQL State: " + e.getSQLState());
+            System.out.println("Error Code: " + e.getErrorCode());
+            System.out.println("Error Message: " + e.getMessage());
+        }
+    }
+
+    /**
+     * Returns all accounts ordered by ID.
+     */
+    public List<Account> getAllAccounts() {
+        String sql = "SELECT ID, FIRST_NAME, LAST_NAME, PHONE, ADDRESS, IS_ENABLED, CREATE_DT, MOD_DT " +
+                     "FROM ACCOUNTS ORDER BY ID";
+        List<Account> accounts = new ArrayList<>();
+        try (PreparedStatement stmt = connection.prepareStatement(sql);
+             ResultSet rs = stmt.executeQuery()) {
+            while (rs.next()) {
+                accounts.add(mapRowToAccount(rs));
+            }
+        } catch (SQLException e) {
+            System.out.println("SQL Error:");
+            System.out.println("SQL State: " + e.getSQLState());
+            System.out.println("Error Code: " + e.getErrorCode());
+            System.out.println("Error Message: " + e.getMessage());
+        }
+        return accounts;
+    }
+
+    /**
+     * Returns all disabled accounts (IS_ENABLED = 'N') ordered by ID.
+     */
+    public List<Account> getDisabledAccounts() {
+        String sql = "SELECT ID, FIRST_NAME, LAST_NAME, PHONE, ADDRESS, IS_ENABLED, CREATE_DT, MOD_DT " +
+                     "FROM ACCOUNTS WHERE IS_ENABLED = 'N' ORDER BY ID";
+        List<Account> accounts = new ArrayList<>();
+        try (PreparedStatement stmt = connection.prepareStatement(sql);
+             ResultSet rs = stmt.executeQuery()) {
+            while (rs.next()) {
+                accounts.add(mapRowToAccount(rs));
+            }
+        } catch (SQLException e) {
+            System.out.println("SQL Error:");
+            System.out.println("SQL State: " + e.getSQLState());
+            System.out.println("Error Code: " + e.getErrorCode());
+            System.out.println("Error Message: " + e.getMessage());
+        }
+        return accounts;
+    }
+
+    /**
+     * Searches accounts by matching the search term against
+     * FIRST_NAME, LAST_NAME, PHONE, or ADDRESS using LIKE wildcards.
+     */
+    public List<Account> searchAccounts(String searchTerm) {
+        String sql = "SELECT ID, FIRST_NAME, LAST_NAME, PHONE, ADDRESS, IS_ENABLED, CREATE_DT, MOD_DT " +
+                     "FROM ACCOUNTS " +
+                     "WHERE FIRST_NAME LIKE ? OR LAST_NAME LIKE ? OR PHONE LIKE ? OR ADDRESS LIKE ? " +
+                     "ORDER BY ID";
+        List<Account> accounts = new ArrayList<>();
+        String wrappedTerm = "%" + searchTerm + "%";
+        try (PreparedStatement stmt = connection.prepareStatement(sql)) {
+            stmt.setString(1, wrappedTerm);
+            stmt.setString(2, wrappedTerm);
+            stmt.setString(3, wrappedTerm);
+            stmt.setString(4, wrappedTerm);
+            try (ResultSet rs = stmt.executeQuery()) {
+                while (rs.next()) {
+                    accounts.add(mapRowToAccount(rs));
+                }
+            }
+        } catch (SQLException e) {
+            System.out.println("SQL Error:");
+            System.out.println("SQL State: " + e.getSQLState());
+            System.out.println("Error Code: " + e.getErrorCode());
+            System.out.println("Error Message: " + e.getMessage());
+        }
+        return accounts;
+    }
+
+    /**
+     * Displays accounts in a tabular format matching the COBOL output.
+     */
+    public void displayAccounts(List<Account> accounts) {
+        System.out.println();
+        System.out.println("ACCOUNTS:");
+        System.out.println();
+        System.out.printf(" %-5s | %-8s | %-8s | %-10s | %-22s | %-7s%n",
+                "ID", "First", "Last", "Phone", "Address", "Enabled");
+        System.out.println("------|----------|----------|------------|------------------------|---------");
+
+        for (Account account : accounts) {
+            System.out.printf(" %-5d | %-8s | %-8s | %-10s | %-22s | %s%n",
+                    account.getId(),
+                    account.getFirstName(),
+                    account.getLastName(),
+                    account.getPhone(),
+                    account.getAddress(),
+                    account.getIsEnabled());
+        }
+    }
+
+    /**
+     * Maps a ResultSet row to an Account object.
+     */
+    private Account mapRowToAccount(ResultSet rs) throws SQLException {
+        return new Account(
+                rs.getInt("ID"),
+                rs.getString("FIRST_NAME"),
+                rs.getString("LAST_NAME"),
+                rs.getString("PHONE"),
+                rs.getString("ADDRESS"),
+                rs.getString("IS_ENABLED"),
+                rs.getString("CREATE_DT"),
+                rs.getString("MOD_DT")
+        );
+    }
+}