Spring事物处理（代码实现）

TransactionTemplate这个类是Spring的事务处理模板,在它的execute()方法里定义事务处理的骨架代码.

但execute()方法的TransactionCallback参数倒是个接口,在这接口中定义了doInTransaction()方法

只要实现TransactionCallback接口,并在doInTransaction()方法里编写具体要进行的事务处理的代码就能够 了.

代码截图

 

 

import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowCallbackHandler;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.TransactionCallback;
import org.springframework.transaction.support.TransactionTemplate;

import com.sunflower.entity.People;


public class BankDaoImp implements BankDao {
	private JdbcTemplate jdbcTemplate;
	private TransactionTemplate transactionTemplate;

	public JdbcTemplate getJdbcTemplate() {
		return jdbcTemplate;
	}

	public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
		this.jdbcTemplate = jdbcTemplate;
	}

	public TransactionTemplate getTransactionTemplate() {
		return transactionTemplate;
	}

	public void setTransactionTemplate(TransactionTemplate transactionTemplate) {
		this.transactionTemplate = transactionTemplate;
	}

	@Override
	public double getMoney(final People people) {
		double money = people.getMoney();
		// 开始事务，若是出现情况则回滚
		transactionTemplate.execute(new TransactionCallback<People>() {
			@Override
			public People doInTransaction(TransactionStatus ts) {
				try {
					final People people2 = new People();
					// 使用JdbcTemplate进行持久化层操做
					String sql = "select money from bank where name = ?";
					Object[] params = new Object[] { people.getName() };
					// 查询
					jdbcTemplate.query(sql, params, new RowCallbackHandler() {
						@Override
						public void processRow(ResultSet rs)
								throws SQLException {
							people2.setMoney(rs.getDouble("money"));
							System.out.println(people.getName() + "用户还有"
									+ rs.getDouble("money") + "元余款");
							System.out.println(people.getName() + "要从帐户中取出"
									+ people.getMoney() + "元");
							if (people2.getMoney() < people.getMoney()) {
								System.out.println("余额不足");
								people.setMoney(-1);
								return;
							}
						}
					});

					if (people.getMoney() < 0)
						return null;
					else {
						sql = "update bank set money = ? where name = ?";
						Object[] params2 = new Object[] {
								people2.getMoney() - people.getMoney(),
								people.getName() };
						jdbcTemplate.update(sql, params2);
						System.out.println("剩余余额:"
								+ (people2.getMoney() - people.getMoney()));
					}
				} catch (Exception e) {
					ts.setRollbackOnly();
				}

				// 若是成功，事务被提交
				return people;
			}
		});

		return people.getMoney();
	}
}