📄 usetran.jsp

📁 此资源是jsp应用开发邓子云等编写的一书里的源代码

💻 JSP

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<%@ page language="java" contentType="text/html; charset=GBK"%>
<%@ page import="java.sql.*,javax.naming.*,javax.sql.*" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>    
    <title>使用数据库事务</title>
  </head>  
  <body>
  <%
   Connection con = null;
	try {
			// 通过连接池来获得一个连接
			Context initContext = new InitialContext();
			Context envContext  = (Context)initContext.lookup("java:/comp/env");
			DataSource ds = (DataSource)envContext.lookup("jdbc/sqlserver");
			con = ds.getConnection();
			PreparedStatement updateAge = null;
			String updateString = "update student "
					+ "set age = ? where name like ?";			
		
			updateAge = con.prepareStatement(updateString);
			int[] age = { 45, 39, 25, 96 };
			String[] names = { "梁朝伟%", "贝壳汗母%", "小罗%", "霍元甲%" };
			int len = age.length;

			// 设置事务提交模式为非自动提交
			con.setAutoCommit(false);

			for (int i = 0; i < len; i++) {
				updateAge.setInt(1, age[i]);
				updateAge.setString(2, names[i]);
				updateAge.executeUpdate();
			}
			// 上面执行的语句，如果不出现异常则提交 SQL 语句
			con.commit();
			out.println("<h1>修改成功，事务执行完毕</h1>");

		} catch (NamingException ex) {
			System.out.println("Name Not Bound : " + ex.getMessage());
		} catch (SQLException ex) {
			System.out.println("SQLException: " + ex.getMessage());
			if (con != null) {
				try {
					System.out.print("Transaction is being ");
					System.out.println("rolled back");
					// 如果出现异常则事务回滚
					con.rollback();
				} catch (SQLException excep) {
					System.out.print("SQLException: ");
					System.out.println(excep.getMessage());
				}
			}
		} finally {// 不管发生不发生异常，要关闭连接，释放资源
			try {
				if (con != null) {					
					con.close();
				}

			} catch (Exception e) {
				e.printStackTrace();
			}
		}

   %>    
  </body>
</html>

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