src/main/java/org/onap/dmaap/dbcapi/database/TableHandler.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * org.onap.dmaap
   4  * ================================================================================
   5  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=========================================================
  19  */
  20
  21 package org.onap.dmaap.dbcapi.database;
  22
  23 import java.lang.reflect.*;
  24
  25 import java.sql.Connection;
  26 import java.sql.DatabaseMetaData;
  27 import java.sql.ResultSet;
  28 import java.sql.SQLException;
  29 import java.util.HashMap;
  30 import java.util.Map;
  31 import java.util.Vector;
  32
  33 class TableHandler<C>   {
  34         protected ConnectionFactory cf;
  35         protected boolean       haskey;
  36         protected String        delstmt;
  37         protected String        insorreplstmt;
  38         protected String        getstmt;
  39         protected String        liststmt;
  40         protected String        initstmt;
  41         protected Class<C>      cls;
  42         protected DBFieldHandler[] fields;
  43         private static Map<String, Map<String, DBFieldHandler.SqlOp>> exceptions = new HashMap<>();
  44         private String select = "SELECT ";
  45         private String from = " FROM ";
  46
  47         protected TableHandler(Class<C> cls, String tabname, String keyname) throws Exception {
  48                 this(ConnectionFactory.getDefaultInstance(), cls, tabname, keyname);
  49         }
  50         protected TableHandler(ConnectionFactory cf, Class<C> cls, String tabname, String keyname) throws Exception {
  51                 this.cf = cf;
  52                 Connection c = null;
  53                 try {
  54                         c = cf.get(false);
  55                         setup(c.getMetaData(), cls, tabname, keyname);
  56                 } finally {
  57                         if (c != null) {
  58                                 cf.release(c);
  59                         }
  60                 }
  61         }
  62
  63         public static void setSpecialCase(String dbtabname, String dbfldname, DBFieldHandler.SqlOp handler) {
  64                 Map<String, DBFieldHandler.SqlOp> m = exceptions.get(dbtabname);
  65                 if (m == null) {
  66                         m = new HashMap<>();
  67                         exceptions.put(dbtabname, m);
  68                 }
  69                 m.put(dbfldname, handler);
  70         }
  71         public static DBFieldHandler.SqlOp getSpecialCase(String dbtabname, String dbfldname) {
  72                 Map<String, DBFieldHandler.SqlOp> m = exceptions.get(dbtabname);
  73                 if (m != null) {
  74                         return(m.get(dbfldname));
  75                 }
  76                 return(null);
  77         }
  78
  79         private void setup(DatabaseMetaData dmd, Class<C> cls, String tabname, String keyname) throws Exception {
  80                 this.cls = cls;
  81                 Vector<DBFieldHandler> h = new Vector<>();
  82                 String qualifiedTableName = String.format( "%s.%s", cf.getSchema(), tabname );
  83                 ResultSet rs = dmd.getColumns("", cf.getSchema(), tabname, null);
  84                 StringBuilder sb1 = new StringBuilder();
  85                 StringBuilder sb2 = new StringBuilder();
  86                 StringBuilder sb3 = new StringBuilder();
  87                 int     count = 0;
  88                 while (rs.next()) {
  89                         if (!rs.getString(3).equals(tabname)) {
  90                                 continue;
  91                         }
  92                         String cname = rs.getString(4);
  93                         if (cname.equals(keyname)) {
  94                                 haskey = true;
  95                                 continue;
  96                         }
  97                         sb1.append(", ").append(cname);
  98                         sb2.append(", ?");
  99                         sb3.append(", EXCLUDED.").append(cname);
 100                         count++;
 101                         h.add(new DBFieldHandler(cls, cname, count, getSpecialCase(tabname, cname)));
 102                 }
 103                 if (count == 0) {
 104                         throw new SQLException("Table " + tabname + " not found");
 105                 }
 106                 String clist = sb1.substring(2);
 107                 String qlist = sb2.substring(2);
 108                 String elist = sb3.substring(2);
 109                 if (keyname != null && !haskey) {
 110                         throw new SQLException("Table " + tabname + " does not have key column " + keyname + " not found");
 111                 }
 112                 if (haskey) {
 113                         count++;
 114                         h.add(new DBFieldHandler(cls, keyname, count, getSpecialCase(tabname, keyname)));
 115                         delstmt = "DELETE FROM " + qualifiedTableName + " WHERE " + keyname + " = ?";
 116                         insorreplstmt = "INSERT INTO " + qualifiedTableName + " (" + clist + ", " + keyname + ") VALUES (" + qlist + ", ?) ON CONFLICT(" + keyname + ") DO UPDATE SET (" + clist + ") = (" + elist + ")";
 117                         getstmt = select + clist + ", " + keyname + from + qualifiedTableName + " WHERE " + keyname + " = ?";
 118                         liststmt = select + clist + ", " + keyname + from + qualifiedTableName;
 119                 } else {
 120                         delstmt = "DELETE FROM " + qualifiedTableName;
 121                         initstmt = "INSERT INTO " + qualifiedTableName + " (" + clist + ") VALUES (" + qlist + ")";
 122                         insorreplstmt = "UPDATE " + qualifiedTableName + " SET (" + clist + ") = (" + qlist + ")";
 123                         getstmt = select + clist + ", " + keyname + from + qualifiedTableName;
 124                 }
 125                 fields = h.toArray(new DBFieldHandler[h.size()]);
 126         }
 127 }