JDBC基础入门（3）

/**
 * @author jifang
 * @since 16/2/19 下午5:02.
 */
public class TransactionClient {
    private Connection connection = ConnectionManger.getConnection("common.properties");
    @Test
    public void noTransaction() throws SQLException {
        try (
                PreparedStatement minusSM = connection.prepareStatement("UPDATE `account` SET `money`=(`money` - ?) WHERE `name`=?");
                PreparedStatement addSM = connection.prepareStatement("UPDATE `account` SET `money`=(`money` + ?) WHERE `name`=?")
        ) {
            // 从feiqing账户转出
            minusSM.setBigDecimal(1, new BigDecimal(100));
            minusSM.setString(2, "feiqing");
            minusSM.execute();
            // 中途抛出异常, 会导致两账户前后不一致
            if (true){
                throw new RuntimeException("no-transaction");
            }
            // 转入xiaofang账户
            addSM.setBigDecimal(1, new BigDecimal(100));
            addSM.setString(2, "xiaofang");
            addSM.execute();
        }
    }
    @After
    public void tearDown() {
        try {
            connection.close();
        } catch (SQLException e) {
        }
    }
}

@Test
public void byTransaction() throws SQLException {
    boolean autoCommitFlag = connection.getAutoCommit();
    // 关闭自动提交, 开启事务
    connection.setAutoCommit(false);
    try (
            PreparedStatement minusSM = connection.prepareStatement("UPDATE `account` SET `money`=(`money` - ?) WHERE `name`=?");
            PreparedStatement addSM = connection.prepareStatement("UPDATE `account` SET `money`=(`money` + ?) WHERE `name`=?")
    ) {
        // 从feiqing账户转出
        minusSM.setBigDecimal(1, new BigDecimal(100));
        minusSM.setString(2, "feiqing");
        minusSM.execute();
        // 中途抛出异常: rollback
        if (true) {
            throw new RuntimeException("no-transaction");
        }
        // 转入xiaofang账户
        addSM.setBigDecimal(1, new BigDecimal(100));
        addSM.setString(2, "xiaofang");
        addSM.execute();
        connection.commit();
    } catch (Throwable e) {
        connection.rollback();
        throw new RuntimeException(e);
    } finally {
        connection.setAutoCommit(autoCommitFlag);
    }
}

public class SQLClient {
    private Connection connection = null;
    private Random random = new Random();
    @Before
    public void setUp() {
        connection = ConnectionManger.getConnectionHikari("common.properties");
    }
    @Test
    public void updateBatch() throws SQLException {
        List<String> sqlList = Lists.newArrayListWithCapacity(10);
        for (int i = 0; i < 10; ++i) {
            sqlList.add("INSERT INTO user(name, password) VALUES('student" + i + "','" + encodeByMd5(random.nextInt() + "") + "')");
        }
        int[] results = update(connection, sqlList);
        for (int result : results) {
            System.out.printf("%d ", result);
        }
    }
    private int[] update(Connection connection, List<String> sqlList) {
        boolean autoCommitFlag = false;
        try {
            autoCommitFlag = connection.getAutoCommit();
            // 关闭自动提交, 打开事务
            connection.setAutoCommit(false);
            // 收集SQL语句
            Statement statement = connection.createStatement();
            for (String sql : sqlList) {
                statement.addBatch(sql);
            }
            // 批量执行 & 提交事务
            int[] result = statement.executeBatch();
            connection.commit();
            return result;
        } catch (SQLException e) {
            try {
                connection.rollback();
            } catch (SQLException ignored) {
            }
            throw new RuntimeException(e);
        } finally {
            try {
                connection.setAutoCommit(autoCommitFlag);
            } catch (SQLException ignored) {
            }
        }
    }
    private String encodeByMd5(String input) {
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            BASE64Encoder base64Encoder = new BASE64Encoder();
            return base64Encoder.encode(md5.digest(input.getBytes("utf-8")));
        } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }
    @After
    public void tearDown() {
        try {
            connection.close();
        } catch (SQLException ignored) {
        }
    }
}

<dependency>
    <groupId>commons-dbutils</groupId>
    <artifactId>commons-dbutils</artifactId>
    <version>1.6</version>
</dependency>

int update(String sql, Object... params);
int update(Connection conn, String sql, Object... params);
/**
 * @author jifang
 * @since 16/2/20 上午10:25.
 */
public class QueryRunnerClient {
    @Test
    public void update() throws SQLException {
        QueryRunner runner = new QueryRunner(ConnectionManger.getDataSourceHikari("common.properties"));
        String sql = "INSERT INTO t_ddl(username, password) VALUES(?, ?)";
        runner.update(sql, "fq", "fq_password");
    }
}

public class QueryRunnerClient {
    // ...
    @Test
    public void select() throws SQLException {
        QueryRunner runner = new QueryRunner();
        String sql = "SELECT * FROM t_ddl WHERE id = ?";
        TDDL result = runner.query(ConnectionManger.getConnectionHikari("common.properties"), sql, rsh, 7);
        System.out.println(result);
    }
    private ResultSetHandler<TDDL> rsh = new ResultSetHandler<TDDL>() {
        @Override
        public TDDL handle(ResultSet rs) throws SQLException {
            TDDL tddl = new TDDL();
            if (rs.next()) {
                tddl.setId(rs.getInt(1));
                tddl.setUsername(rs.getString(2));
                tddl.setPassword(rs.getString(3));
            }
            return tddl;
        }
    };
    private static class TDDL {
        private Integer id;
        private String username;
        private String password;
        public Integer getId() {
            return id;
        }
        public void setId(Integer id) {
            this.id = id;
        }
        public String getUsername() {
            return username;
        }
        public void setUsername(String username) {
            this.username = username;
        }
        public String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }
        @Override
        public String toString() {
            return "TDDL{" +
                    "id=" + id +
                    ", username='" + username + ''' +
                    ", password='" + password + ''' +
                    '}';
        }
    }
}

public class QueryRunnerClient {
    private QueryRunner runner = new QueryRunner(ConnectionManger.getDataSourceHikari("common.properties"));
    @Test
    public void clientBeanHandler() throws SQLException {
        String sql = "SELECT * FROM t_ddl WHERE id = ?";
        TDDL result = runner.query(sql, new BeanHandler<>(TDDL.class), 7);
        System.out.println(result);
    }
    @Test
    public void clientBeanListHandler() throws SQLException {
        String sql = "SELECT * FROM t_ddl";
        List<TDDL> result = runner.query(sql, new BeanListHandler<>(TDDL.class));
        System.out.println(result);
    }
    @Test
    public void clientScalarHandler() throws SQLException {
        String sql = "SELECT COUNT(*) FROM t_ddl";
        Long result = runner.query(sql, new ScalarHandler<Long>());
        System.out.println(result);
    }
    @Test
    public void clientColumnListHandler() throws SQLException {
        String sql = "SELECT * FROM t_ddl";
        List<String> query = runner.query(sql, new ColumnListHandler<String>("username"));
        for (String i : query) {
            System.out.printf("%n%s", i);
        }
    }
}

public class QueryRunnerClient {
    private QueryRunner runner = new QueryRunner(ConnectionManger.getDataSourceHikari("common.properties"));
    private Random random = new Random();
    @Test
    public void clientBeanHandler() throws SQLException {
        String sql = "INSERT INTO t_ddl(username, password) VALUES(?, ?)";
        int count = 46;
        Object[][] params = new Object[count][];
        for (int i = 0; i < count; ++i) {
            params[i] = new Object[]{"student-" + i, "password-" + random.nextInt()};
        }
        runner.batch(sql, params);
    }
}