用java判断数据库表是否被创建

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session=HibernateSessionFactory.getSession();
Connection conn=session.connection();
//判断数据库中是否存在表RiseNet_file
DatabaseMetaData dmd=conn.getMetaData();
/**
               *DatabaseMetaData.getTablesgetTables(String catalog,
                           String schemaPattern,
                           String tableNamePattern,
                           String[] types)
                    throws SQLException
*参数一:表种类,这个我没有找到是什么意思,如果是null的话,则为全部
*参数二:为当前用户的名字,如果不写则为查找所有用户
*参数三:表名称,可以使用正则表达式,
*参数四:表类型:主要包括:"TABLE", "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY", "LOCAL TEMPORARY", "ALIAS", "SYNONYM".
ResultSet 中取得的结果包括以下内容:

TABLE_CAT String => table catalog (may be null)
TABLE_SCHEM String => table schema (may be null)
TABLE_NAME String => table name
TABLE_TYPE String => table type. Typical types are "TABLE", "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY", "LOCAL TEMPORARY", "ALIAS", "SYNONYM".
REMARKS String => explanatory comment on the table
TYPE_CAT String => the types catalog (may be null)
TYPE_SCHEM String => the types schema (may be null)
TYPE_NAME String => type name (may be null)
SELF_REFERENCING_COL_NAME String => name of the designated "identifier" column of a typed table (may be null)
REF_GENERATION String => specifies how values in SELF_REFERENCING_COL_NAME are created. Values are "SYSTEM", "USER", "DERIVED". (may be null)

**/
ResultSet rs=dmd.getTables("", "RISEAPPROVE", "RISENET_FILE", (new String[]{"TABLE"}));
//ResultSetMetaData meta = rs.getMetaData();
//System.out.println(meta.getColumnCount());
// (int i = 1; i <= meta.getColumnCount(); i++) {
//System.out.println("---"+meta.getCatalogName(i)+"---");
//}
while(rs.next()){
System.out.println("表存在,删除表");
System.out.println("TABLE_CAT:"+rs.getString("TABLE_CAT"));
System.out.println("TABLE_SCHEM:"+rs.getString("TABLE_SCHEM"));
System.out.println("TABLE_NAME:"+rs.getString("TABLE_NAME"));
System.out.println("TABLE_TYPE:"+rs.getString("TABLE_TYPE"));

System.out.println("END");
// Transaction tx = session.beginTransaction();
// RiseFile risefile=newRiseFile();
// //添加数据,或者用session.saveOrUpdate(risefile);
//
// session.save(risefile);
// //在提交以前会把title变成第二次测试
//
// List list=session.find("from RiseFile where fileguid='{09A26D19-FFFF-FFFF-E0D7-FF4100000001}'");
// if(list!=null&&list.size()>0){
// RiseFile file=(RiseFile)list.get(0);
// System.out.println(file.getAppName());
// System.out.println(file.getTitile());
// }
// session.delete("from RiseFile where fileguid='{09A26D19-FFFF-FFFF-E0D7-FF4100000001}'");
//
// risefile.setTitile("第N次测试");
//
// tx.commit();
// //删除表
//operateTable(true);
}//else{
//创建表
// System.out.println("表不存在,创建表");
//operateTable(false);
//}