Question

import java.sql.SQLException;

public class JDBC {

    public void create(User user) throws SQLException {

        try (
            Connection connection = dataSource.getConnection();
            PreparedStatement statement = connection.prepareStatement(SQL_INSERT,Statement.RETURN_GENERATED_KEYS);
        ) {
            statement.setString(1, user.getName());
            statement.setString(2, user.getPassword());
            statement.setString(3, user.getEmail());
            // ...

            int affectedRows = statement.executeUpdate();

            if (affectedRows == 0) {
                throw new SQLException("Creating user failed, no rows affected.");
            }

            try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
                if (generatedKeys.next()) {
                    user.setId(generatedKeys.getLong(1));
                }
                else {
                    throw new SQLException("Creating user failed, no ID obtained.");
                }
            }
        }
    }
}

Answer 1

异常处理是处理错误的唯一方法。根据所编写的应用程序类型，您可以使用Spring的AOP为例。这将需要付出额外的努力来理解面向方面的编程。

这些评论非常相关，也许您可以详细说明您要实现的目标。解释这是找到答案的最佳方法；您很有可能会被带到一个全新的解决方案。

Answer 2

try-with-resources代码很好，尽管在语法上确实有些参差不齐。

您可能只包装了代码以供重用：

public <DTO> void create(DTO dto, DataSource dataSource, String insertSQL,
        BiConsumer<PreparedStatement, DTO> paramSetter,
        BiConsumer<DTO, Long> primaryKeySetter) throws SQLException {
    try (
        Connection connection = dataSource.getConnection();
        PreparedStatement statement = connection.prepareStatement(insertSQL,
                                      Statement.RETURN_GENERATED_KEYS);
    ) {
        parameterSetter.apply(statement, dto);
        int affectedRows = statement.executeUpdate();

        if (affectedRows == 0) {
            throw new SQLException("Creating failed, no rows affected.");
        }

        try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
            if (generatedKeys.next()) {
                primaryKeySetter.apply(dto, generatedKeys.getLong(1));
            }
            else {
                throw new SQLException("Creating user failed, no ID obtained.");
            }
        }
    }
}


create(user, dataSource, SQL_INSERT,
    statement -> {
        statement.setString(1, user.getName());
        statement.setString(2, user.getPassword());
        statement.setString(3, user.getEmail());
    },
    (dto, id) -> dto.setId(id));

是否有另一种方式来处理异常而不是“异常处理”？

2 个答案: