32) Tomcat's JDBC PoolTomcat jdbc pool的使用仅需2个jar包，分别为tomcat-jdbc.jar和tomcat-juli.jar，这两个jar包都可以在tomcat7中找到，tomcat-jdbc.jar在tomcat的lib目录下，tomcat-juli.jar在bin目录下。http://svn.apache.org/viewvc/tomcat/trunk/modules/jdbc-pool/org.apache.tomcat.jdbc.pool  import java.sql.Connection;  import java.sql.ResultSet;  import java.sql.Statement;  import org.apache.tomcat.jdbc.pool.DataSource;  import org.apache.tomcat.jdbc.pool.PoolProperties;  public class SimplePOJOExample {      public static void main(String[] args) throws Exception {          PoolProperties p = new PoolProperties();          p.setUrl("jdbc:mysql://localhost:3306/mysql");          p.setDriverClassName("com.mysql.jdbc.Driver");          p.setUsername("root");          p.setPassword("password");          p.setJmxEnabled(true);          p.setTestWhileIdle(false);          p.setTestOnBorrow(true);          p.setValidationQuery("SELECT 1");          p.setTestOnReturn(false);          p.setValidationInterval(30000);          p.setTimeBetweenEvictionRunsMillis(30000);          p.setMaxActive(100);          p.setInitialSize(10);          p.setMaxWait(10000);          p.setRemoveAbandonedTimeout(60);          p.setMinEvictableIdleTimeMillis(30000);          p.setMinIdle(10);          p.setLogAbandoned(true);          p.setRemoveAbandoned(true);          p.setJdbcInterceptors(            "org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;"+            "org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");          DataSource datasource = new DataSource();          datasource.setPoolProperties(p);          Connection con = null;          try {            con = datasource.getConnection();            Statement st = con.createStatement();            ResultSet rs = st.executeQuery("select * from user");            int cnt = 1;            while (rs.next()) {                System.out.println((cnt++)+". Host:" +rs.getString("Host")+                  " User:"+rs.getString("User")+" Password:"+rs.getString("Password"));            }            rs.close();            st.close();          } finally {            if (con!=null) try {con.close();}catch (Exception ignore) {}          }      }  }ProxyConnectionProxyConnectionPooledConnection con = idle.poll();ProxyConnection[PooledConnection[null]]00 00 00 00 03 73 65 6c     . . . . . s e l65 63 74 20 2a 20 46 52     e c t . * . F R4f 4d 20 74 63 5f 63 6f     O M . t c _ c o64 65 20 57 48 45 52 45     d e . W H E R E20 43 4f 44 45 5f 49 44     . C O D E _ I D3d 27 31 30 30 35 31 30     = ' 1 0 0 5 1 0 0 2 '30 32 27EscapeProcessorObject escapedSqlResult = EscapeProcessor.escapeSQL(sql, serverSupportsConvertFn(), getMultiHostSafeProxy()); EscapeTokenizer escapeTokenizer = new EscapeTokenizer(sql);[49, 48, 48, 53, 49, 48, 48, 50][39, 49, 48, 48, 53, 49, 48, 48, 50, 39][39, 49, 48, 48, 53, 49, 48, 48, 50, 39][[39, 49, 48, 48, 53, 49, 48, 48, 50, 39]]Buffer sendPacket = fillSendPacket();Buffer sendPacket = this.connection.getIO().getSharedSendPacket();this.position = MysqlIO.HEADER_LENGTH;this.results = executeInternal(this.maxRows, sendPacket, createStreamingResultSet(), true, metadataFromCache, false);Buffer getSharedSendPacket() {    if (this.sharedSendPacket == null) {        this.sharedSendPacket = new Buffer(INITIAL_PACKET_SIZE);    }    return this.sharedSendPacket;}protected MySQLConnection checkClosed() throws SQLException {    MySQLConnection c = this.connection;    if (c == null) {        throw SQLError.createSQLException(Messages.getString("Statement.49"), SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());    }    return c;}public ResultSetInternalMethods execSQL(StatementImpl callingStatement, String sql, int maxRows, Buffer packet, int resultSetType, int resultSetConcurrency,            boolean streamResults, String catalog, Field[] cachedMetadata, boolean isBatch) throws SQLException return this.io.sqlQueryDirect(callingStatement, null, null, packet, maxRows, resultSetType, resultSetConcurrency, streamResults, catalog,                        cachedMetadata);StatementImplBuffer resultPacket = sendCommand(MysqlDefs.QUERY, null, queryPacket, false, null, 0);