mysql的PreparedStatement

环境为
mysql 5.1.39
mysql-connector-j  5.1.11
测试代码

public static void main(String[] args) throws Exception {
Connection conn = getConnection();

PreparedStatement ps = conn
.prepareStatement("select * from test where name=?");
ps.setInt(1, 1);
ps.execute();

Statement stmt = conn.createStatement();

stmt.execute("select * from test where name=1");

conn.commit();
conn.close();

}

private static Connection getConnection() throws Exception {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/db_test?useServerPrepStmts=false",
"db_test", "db_test");
conn.setAutoCommit(false);
return conn;
}

在mysql驱动url中如果设置useServerPrepStmts=false,那么上面两条语句执行时，向服务器发送的数据包一样（用wireshark抓包工具加断点看到）。
如果设置useServerPrepStmts=true，那么执行conn.prepareStatement("select * from test where name=?");语句时，会向服务器发送命令，告知这条语句，执行ps.execute();时则只发送参数和语句编号。此时在服务器端
mysql> show global status like 'Com_stmt%' ;
可以看到 Com_stmt_prepare数量增加。