[ch03] Apply template method pattern. (deleteAll).

src/main/java/ch03/springbook/user/dao/UserDao.java

@@ -0,0 +1,118 @@
+package ch03.springbook.user.dao;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import javax.sql.DataSource;
+
+import org.springframework.dao.EmptyResultDataAccessException;
+
+import ch01.springbook.user.dao.ConnectionMaker;
+import ch01.springbook.user.domain.User;
+
+public abstract class UserDao {
+
+	private ConnectionMaker connectionMaker;
+	private DataSource dataSource;
+
+	public UserDao() {
+
+	}
+
+	public UserDao(ConnectionMaker connectionMaker) {
+		this.connectionMaker = connectionMaker;
+	}
+
+	public void setDataSource(DataSource dataSource) {
+		this.dataSource = dataSource;
+	}
+
+	public void setConnectionMaker(ConnectionMaker connectionMaker) {
+		this.connectionMaker = connectionMaker;
+	}
+
+	public void add(User user) throws ClassNotFoundException, SQLException {
+		Connection c = dataSource.getConnection();
+
+		PreparedStatement ps = c.prepareStatement(
+			"INSERT INTO users(id, name, password) VALUES(?, ?, ?)");
+		ps.setString(1, user.getId());
+		ps.setString(2, user.getName());
+		ps.setString(3, user.getPassword());
+
+		ps.executeUpdate();
+
+		ps.close();
+		c.close();
+	}
+
+	public User get(String id) throws ClassNotFoundException, SQLException {
+		Connection c = dataSource.getConnection();
+
+		PreparedStatement ps = c.prepareStatement(
+			"SELECT * FROM users WHERE id = ?");
+		ps.setString(1, id);
+
+		ResultSet rs = ps.executeQuery();
+
+		User user = null;
+
+		if (rs.next()) {
+			user = new User();
+			user.setId(rs.getString("id"));
+			user.setName(rs.getString("name"));
+			user.setPassword(rs.getString("password"));
+		}
+
+		rs.close();
+		ps.close();
+		c.close();
+
+		if (user == null) {
+			throw new EmptyResultDataAccessException(1);
+		}
+
+		return user;
+	}
+
+	public void deleteAll() throws SQLException {
+
+		Connection c = null;
+		PreparedStatement ps = null;
+
+		try {
+
+			c = dataSource.getConnection();
+			ps = makeStatement(c);
+
+			ps.executeUpdate();
+
+		} catch (SQLException e) {
+			throw e;
+		} finally {
+			if (ps != null) { try { ps.close(); } catch (SQLException e) {} }
+			if (c != null) { try { c.close(); } catch (SQLException e) {} }
+		}
+	}
+
+	public int getCount() throws SQLException {
+		Connection c = dataSource.getConnection();
+
+		PreparedStatement ps = c.prepareStatement("select count(*) from users");
+
+		ResultSet rs = ps.executeQuery();
+		rs.next();
+
+		int count = rs.getInt(1);
+
+		rs.close();
+		ps.close();
+		c.close();
+
+		return count;
+	}
+
+	abstract protected PreparedStatement makeStatement(Connection c) throws SQLException;
+}

src/main/java/ch03/springbook/user/dao/UserDaoDeleteAll.java

@@ -0,0 +1,14 @@
+package ch03.springbook.user.dao;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+
+public class UserDaoDeleteAll extends UserDao {
+
+	protected PreparedStatement makeStatement(Connection c) throws SQLException {
+		PreparedStatement ps;
+		ps = c.prepareStatement("delete from users");
+		return ps;
+	}
+}