Java Web-based JdbcUtils tool class final and javawebjdbcutils

Java Web-based JdbcUtils tool class final and javawebjdbcutils

The final version of JdbcUtils tool class 3.0 adds transaction-related functions and release links. The final version can be directly packaged into a jar package, which will be used in subsequent basic projects.

1. JdbcUtils code

1/** 2 * Final Version 3 * @ author hui. zhang 4*5 */6 public class JdbcUtils {7 // default configuration file, must be given c3p0-config.xml 8 private static combooleddatasource dataSource = new combooleddatasource (); 9 10 // transaction dedicated Connection 11 private static ThreadLocal <Connection> tl = new ThreadLocal <Connection> (); 12/** 13 * use the Connection pool to return a Connection object 14 * @ return15 * @ throws SQLException16 */17 public static Connection getConnection () throws SQLExc Eption {18 Connection con = tl. get (); 19 // when con ratio is null, transaction 20 if (con! = Null) return con; 21 return dataSource. getConnection (); 22} 23 24/** 25 * returned connection pool object 26 * @ return27 */28 public static DataSource getDataSource () {29 return dataSource; 30} 31 32/** 33 * Start transaction 34*1. get a Connection and set its setAutoCommit (false) 35*2. make sure that the Connection used in dao is the 36 * @ throws SQLException 37 */38 public static void beginTransaction () throws SQLException {39 Connection con = tl. get (); 40 if (con! = Null) throw new SQLException ("the transaction has been enabled. Please do not enable it again! "); 41 con = getConnection (); 42 con. setAutoCommit (false); 43 tl. set (con); 44} 45 46/** 47 * commit transaction 48*1. obtain the Connection provided by beginTransaction, and then call the commit method 49 * @ throws SQLException 50 */51 public static void commitTransaction () throws SQLException {52 Connection con = tl. get (); 53 if (con = null) throw new SQLException ("the transaction has not been started and cannot be committed! "); 54 con. commit (); 55 con. close (); 56 tl. remove (); 57} 58 59/** 60 * roll back transaction 61*1. obtain the Connection provided by beginTransaction, and then call the rollback method 62 * @ throws SQLException 63 */64 public static void rollbackTransaction () throws SQLException {65 Connection con = tl. get (); 66 if (con = null) throw new SQLException ("the transaction has not been started and cannot be rolled back! "); 67 con. rollback (); 68 con. close (); 69 tl. remove (); 70} 71 72/** 73 * release Connection 74 * @ param connection75 * @ throws SQLException 76 */77 public static void releaseConnection (connection Connection) throws SQLException {78 Connection con = tl. get (); 79 // determines whether it is a dedicated transaction connection. if it is not necessary to close 80 if (con = null) 81 connection. close (); 82 // If con! = Null indicates that a transaction exists. You need to determine whether the parameter connection is the same as con! = Connection) 85 connection. close (); 86} 87}

2. Give the c3p0-config.xml configuration file under src

<? Xml version = "1.0" encoding = "UTF-8"?> <C3p0-config> <! -- Default configuration information --> <default-config> <! -- Four major connection parameters --> <property name = "user"> root </property> <property name = "password"> 123 </property> <property name = "driverClass"> com. mysql. jdbc. driver </property> <property name = "jdbcUrl"> jdbc: mysql: // mydb </property> <! -- Pool parameter configuration --> <property name = "acquireIncrement"> 3 </property> <property name = "initialPoolSize"> 10 </property> <property name = "minPoolSize"> 2 </property> <property name = "maxPoolSize"> 10 </property> </default-config> </c3p0-config>

3. Summary

From the first basic version 1.0 to the connection pool 2.0 to the current transaction, one step at a time. Every version should be left... Let us know new things !!!