Package org.springframework.batch.item.database.support

Class AbstractSqlPagingQueryProvider

  • All Implemented Interfaces:
    PagingQueryProvider
    Direct Known Subclasses:
    H2PagingQueryProvider, HsqlPagingQueryProvider, MySqlPagingQueryProvider, OraclePagingQueryProvider, PostgresPagingQueryProvider, SqlitePagingQueryProvider, SqlWindowingPagingQueryProvider
    public abstract class AbstractSqlPagingQueryProvider
extends java.lang.Object
implements PagingQueryProvider
    Abstract SQL Paging Query Provider to serve as a base class for all provided SQL paging query providers. Any implementation must provide a way to specify the select clause, from clause and optionally a where clause. In addition a way to specify a single column sort key must also be provided. This sort key will be used to provide the paging functionality. It is recommended that there should be an index for the sort key to provide better performance. Provides properties and preparation for the mandatory "selectClause" and "fromClause" as well as for the optional "whereClause". Also provides property for the mandatory "sortKeys". Note: The columns that make up the sort key must be a true key and not just a column to order by. It is important to have a unique key constraint on the sort key to guarantee that no data is lost between executions.
    Since:
    2.0
    Author:
    Thomas Risberg, Dave Syer, Michael Minella, Mahmoud Ben Hassine, Benjamin Hetz

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and TypeMethodDescription
      abstract java.lang.StringgenerateFirstPageQuery​(int pageSize)
      Method generating the query string to be used for retrieving the first page.
      abstract java.lang.StringgenerateJumpToItemQuery​(int itemIndex, int pageSize)
      Method generating the query string to be used for jumping to a specific item position.
      abstract java.lang.StringgenerateRemainingPagesQuery​(int pageSize)
      Method generating the query string to be used for retrieving the pages following the first page.
      protected java.lang.StringgetFromClause() 
      java.lang.StringgetGroupClause()
      The getter for the group by clause
      intgetParameterCount()
      The number of parameters that are declared in the query
      protected java.lang.StringgetSelectClause() 
      java.lang.StringgetSortKeyPlaceHolder​(java.lang.String keyName)
      The sort key placeholder will vary depending on whether named parameters or traditional placeholders are used in query strings.
      java.util.Map<java.lang.String,​Order>getSortKeys()
      A Map<String, Boolean> of sort columns as the key and boolean for ascending/descending (ascending = true).
      java.util.Map<java.lang.String,​Order>getSortKeysWithoutAliases()
      The sort key (unique single column name) without alias.
      protected java.lang.StringgetWhereClause() 
      voidinit​(javax.sql.DataSource dataSource)
      Check mandatory properties.
      booleanisUsingNamedParameters()
      Indicate whether the generated queries use named parameter syntax.
      voidsetFromClause​(java.lang.String fromClause) 
      voidsetGroupClause​(java.lang.String groupClause)
      The setter for the group by clause
      voidsetSelectClause​(java.lang.String selectClause) 
      voidsetSortKeys​(java.util.Map<java.lang.String,​Order> sortKeys) 
      voidsetWhereClause​(java.lang.String whereClause) 

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • AbstractSqlPagingQueryProvider

        public AbstractSqlPagingQueryProvider()

    • Method Detail

      • setGroupClause

        public void setGroupClause​(java.lang.String groupClause)
        The setter for the group by clause
        Parameters:
        groupClause - SQL GROUP BY clause part of the SQL query string

      • getGroupClause

        public java.lang.String getGroupClause()
        The getter for the group by clause
        Returns:
        SQL GROUP BY clause part of the SQL query string

      • setSelectClause

        public void setSelectClause​(java.lang.String selectClause)
        Parameters:
        selectClause - SELECT clause part of SQL query string

      • getSelectClause

        protected java.lang.String getSelectClause()
        Returns:
        SQL SELECT clause part of SQL query string

      • setFromClause

        public void setFromClause​(java.lang.String fromClause)
        Parameters:
        fromClause - FROM clause part of SQL query string

      • getFromClause

        protected java.lang.String getFromClause()
        Returns:
        SQL FROM clause part of SQL query string

      • setWhereClause

        public void setWhereClause​(java.lang.String whereClause)
        Parameters:
        whereClause - WHERE clause part of SQL query string

      • getWhereClause

        protected java.lang.String getWhereClause()
        Returns:
        SQL WHERE clause part of SQL query string

      • setSortKeys

        public void setSortKeys​(java.util.Map<java.lang.String,​Order> sortKeys)
        Parameters:
        sortKeys - key to use to sort and limit page content

      • getSortKeys

        public java.util.Map<java.lang.String,​Order> getSortKeys()
        A Map<String, Boolean> of sort columns as the key and boolean for ascending/descending (ascending = true).
        Specified by:
        getSortKeys in interface PagingQueryProvider
        Returns:
        sortKey key to use to sort and limit page content

      • isUsingNamedParameters

        public boolean isUsingNamedParameters()
        Description copied from interface: PagingQueryProvider
        Indicate whether the generated queries use named parameter syntax.
        Specified by:
        isUsingNamedParameters in interface PagingQueryProvider
        Returns:
        true if named parameter syntax is used

      • getSortKeyPlaceHolder

        public java.lang.String getSortKeyPlaceHolder​(java.lang.String keyName)
        The sort key placeholder will vary depending on whether named parameters or traditional placeholders are used in query strings.
        Specified by:
        getSortKeyPlaceHolder in interface PagingQueryProvider
        Parameters:
        keyName - The sort key name
        Returns:
        place holder for sortKey.

      • init

        public void init​(javax.sql.DataSource dataSource)
          throws java.lang.Exception
        Check mandatory properties.
        Specified by:
        init in interface PagingQueryProvider
        Parameters:
        dataSource - DataSource to use for any initialization
        Throws:
        java.lang.Exception - for errors when initializing
        See Also:
        InitializingBean.afterPropertiesSet()

      • generateFirstPageQuery

        public abstract java.lang.String generateFirstPageQuery​(int pageSize)
        Method generating the query string to be used for retrieving the first page. This method must be implemented in sub classes.
        Specified by:
        generateFirstPageQuery in interface PagingQueryProvider
        Parameters:
        pageSize - number of rows to read per page
        Returns:
        query string

      • generateRemainingPagesQuery

        public abstract java.lang.String generateRemainingPagesQuery​(int pageSize)
        Method generating the query string to be used for retrieving the pages following the first page. This method must be implemented in sub classes.
        Specified by:
        generateRemainingPagesQuery in interface PagingQueryProvider
        Parameters:
        pageSize - number of rows to read per page
        Returns:
        query string

      • generateJumpToItemQuery

        public abstract java.lang.String generateJumpToItemQuery​(int itemIndex,
                                                         int pageSize)
        Method generating the query string to be used for jumping to a specific item position. This method must be implemented in sub classes.
        Specified by:
        generateJumpToItemQuery in interface PagingQueryProvider
        Parameters:
        itemIndex - the index of the item to jump to
        pageSize - number of rows to read per page
        Returns:
        query string

      • getSortKeysWithoutAliases

        public java.util.Map<java.lang.String,​Order> getSortKeysWithoutAliases()
        Description copied from interface: PagingQueryProvider
        The sort key (unique single column name) without alias.
        Specified by:
        getSortKeysWithoutAliases in interface PagingQueryProvider
        Returns:
        sortKey key to use to sort and limit page content (without alias)