[ch03] Use JdbcTemplate.

src/main/java/ch01/springbook/user/dao/UserDao.java

@@ -7,92 +7,75 @@
 
 import javax.sql.DataSource;
 
-import org.springframework.dao.EmptyResultDataAccessException;
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.core.PreparedStatementCreator;
+import org.springframework.jdbc.core.ResultSetExtractor;
+import org.springframework.jdbc.core.RowMapper;
 
 import ch01.springbook.user.domain.User;
-import ch03.springbook.user.dao.JdbcContext;
-import ch03.springbook.user.dao.StatementStrategy;
 
 public class UserDao {
 
-	private JdbcContext jdbcContext;
+	private JdbcTemplate jdbcTemplate;
 	private DataSource dataSource;
 
 	public UserDao() {
 
 	}
 
-	public void setJdbcContext(JdbcContext jdbcContext) {
-		this.jdbcContext = jdbcContext;
-	}
-
 	public void setDataSource(DataSource dataSource) {
+		this.jdbcTemplate = new JdbcTemplate(dataSource);
 		this.dataSource = dataSource;
 	}
 
 	public void add(User user) throws ClassNotFoundException, SQLException {
-
-		this.jdbcContext.workWithStatementStrategy(new StatementStrategy() {
-			@Override
-			public PreparedStatement makePreparedStatement(Connection c) throws SQLException {
-				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());
-
-				return ps;
-			}
-		});
+		this.jdbcTemplate.update("INSERT INTO users(id, name, password) VALUES(?, ?, ?)",
+			user.getId(), user.getName(), user.getPassword());
 	}
 
 	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;
+		return this.jdbcTemplate.queryForObject(
+			"SELECT * FROM users WHERE id = ?",
+			new Object[] {id},
+			new RowMapper<User>() {
+				@Override
+				public User mapRow(ResultSet resultSet, int i) throws SQLException {
 
-		if (rs.next()) {
-			user = new User();
-			user.setId(rs.getString("id"));
-			user.setName(rs.getString("name"));
-			user.setPassword(rs.getString("password"));
-		}
+					User user = new User();
+					user.setId(resultSet.getString("id"));
+					user.setName(resultSet.getString("name"));
+					user.setPassword(resultSet.getString("password"));
 
-		rs.close();
-		ps.close();
-		c.close();
-
-		if (user == null) {
-			throw new EmptyResultDataAccessException(1);
-		}
-
-		return user;
+					return user;
+				}
+			}
+		);
 	}
 
 	public void deleteAll() throws SQLException {
-		this.jdbcContext.executeSql("delete from users");
+		this.jdbcTemplate.update("delete from users");
 	}
 
 	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 this.jdbcTemplate.query(
+			new PreparedStatementCreator() {
+				@Override
+				public PreparedStatement createPreparedStatement(Connection connection) throws SQLException {
+					return connection.prepareStatement("select count(*) from users");
+				}
+			},
+			new ResultSetExtractor<Integer>() {
+				@Override
+				public Integer extractData(ResultSet resultSet) throws SQLException, DataAccessException {
+					resultSet.next();
+					return resultSet.getInt(1);
+				}
+			}
+		);
 
-		return count;
+		// this.jdbcTemplate.queryForInt("select count(*) from users");
 	}
 }

src/main/resources/applicationContext.xml

@@ -18,7 +18,6 @@
     </bean>
 
     <bean id="userDao" class="ch01.springbook.user.dao.UserDao">
-        <property name="jdbcContext" ref="jdbcContext" />
         <property name="dataSource" ref="dataSource" />
     </bean>