Package org.apache.commons.beanutils2.sql

Class RowSetDynaClass

java.lang.Object
org.apache.commons.beanutils2.sql.RowSetDynaClass
All Implemented Interfaces:
DynaClass
public class RowSetDynaClass extends Object

Implements DynaClass to create an in-memory collection of DynaBeans representing the results of an SQL query. Once the DynaClass instance has been created, the JDBC ResultSet and Statement on which it is based can be closed, and the underlying Connection can be returned to its connection pool (if you are using one).

The normal usage pattern is something like: 

   Connection conn = ...;  // Acquire connection from pool
   Statement stmt = conn.createStatement();
   ResultSet rs = stmt.executeQuery("SELECT ...");
   RowSetDynaClass rsdc = new RowSetDynaClass(rs);
   rs.close();
   stmt.close();
   ...;                    // Return connection to pool
   List rows = rsdc.getRows();
   ...;                   // Process the rows as desired

Each column in the result set will be represented as a DynaBean property of the corresponding name (optionally forced to lower case for portability). There will be one DynaBean in the List</code> returned by <code>getRows() for each row in the original ResultSet.

In general, instances of RowSetDynaClass can be serialized and deserialized, which will automatically include the list of DynaBeans representing the data content. The only exception to this rule would be when the underlying property values that were copied from the ResultSet originally cannot themselves be serialized. Therefore, a RowSetDynaClass makes a very convenient mechanism for transporting data sets to remote Java-based application components.

  • Field Details

    • limit

      protected int limit

      Limits the size of the returned list. The call to getRows() will return at most limit number of rows. If less than or equal to 0, does not limit the size of the result.

    • rows

      protected List<DynaBean> rows

      The list of DynaBeans representing the contents of the original ResultSet on which this RowSetDynaClass was based.

    • lowerCase

      protected boolean lowerCase

      Flag defining whether column names should be lower cased when converted to property names.

    • properties

      protected DynaProperty[] properties

      The set of dynamic properties that are part of this DynaClass.

    • propertiesMap

      protected Map<String,DynaProperty> propertiesMap

      The set of dynamic properties that are part of this DynaClass, keyed by the property name. Individual descriptor instances will be the same instances as those in the properties list.

  • Constructor Details

    • RowSetDynaClass

      public RowSetDynaClass(ResultSet resultSet) throws SQLException

      Constructs a new RowSetDynaClass for the specified ResultSet. The property names corresponding to column names in the result set will be lower cased.

      Parameters:
      resultSet - The result set to be wrapped
      Throws:
      NullPointerException - if resultSet is null
      SQLException - if the metadata for this result set cannot be introspected

    • RowSetDynaClass

      public RowSetDynaClass(ResultSet resultSet, boolean lowerCase) throws SQLException

      Constructs a new RowSetDynaClass for the specified ResultSet. The property names corresponding to the column names in the result set will be lower cased or not, depending on the specified lowerCase value.

      If limit</code> is not less than 0, max <code>limit number of rows will be copied into the resultset.
      Parameters:
      resultSet - The result set to be wrapped
      lowerCase - Should property names be lower cased?
      Throws:
      NullPointerException - if resultSet is null
      SQLException - if the metadata for this result set cannot be introspected

    • RowSetDynaClass

      public RowSetDynaClass(ResultSet resultSet, boolean lowerCase, boolean useColumnLabel) throws SQLException

      Constructs a new RowSetDynaClass for the specified ResultSet. The property names corresponding to the column names in the result set will be lower cased or not, depending on the specified lowerCase value.

      WARNING - If you specify false for lowerCase, the returned property names will exactly match the column names returned by your JDBC driver. Because different drivers might return column names in different cases, the property names seen by your application will vary depending on which JDBC driver you are using.

      Parameters:
      resultSet - The result set to be wrapped
      lowerCase - Should property names be lower cased?
      useColumnLabel - true if the column label should be used, otherwise false
      Throws:
      NullPointerException - if resultSet is null
      SQLException - if the metadata for this result set cannot be introspected
      Since:
      1.8.3

    • RowSetDynaClass

      public RowSetDynaClass(ResultSet resultSet, boolean lowerCase, int limit) throws SQLException

      Constructs a new RowSetDynaClass for the specified ResultSet. The property names corresponding to the column names in the result set will be lower cased or not, depending on the specified lowerCase value.

      WARNING - If you specify false for lowerCase, the returned property names will exactly match the column names returned by your JDBC driver. Because different drivers might return column names in different cases, the property names seen by your application will vary depending on which JDBC driver you are using.

      Parameters:
      resultSet - The result set to be wrapped
      lowerCase - Should property names be lower cased?
      limit - Maximum limit for the List of DynaBean
      Throws:
      NullPointerException - if resultSet is null
      SQLException - if the metadata for this result set cannot be introspected

    • RowSetDynaClass

      public RowSetDynaClass(ResultSet resultSet, boolean lowerCase, int limit, boolean useColumnLabel) throws SQLException

      Constructs a new RowSetDynaClass for the specified ResultSet. The property names corresponding to the column names in the result set will be lower cased or not, depending on the specified lowerCase value.

      WARNING - If you specify false for lowerCase, the returned property names will exactly match the column names returned by your JDBC driver. Because different drivers might return column names in different cases, the property names seen by your application will vary depending on which JDBC driver you are using.

      Parameters:
      resultSet - The result set to be wrapped
      lowerCase - Should property names be lower cased?
      limit - Maximum limit for the List of DynaBean
      useColumnLabel - true if the column label should be used, otherwise false
      Throws:
      NullPointerException - if resultSet is null
      SQLException - if the metadata for this result set cannot be introspected
      Since:
      1.8.3

    • RowSetDynaClass

      public RowSetDynaClass(ResultSet resultSet, int limit) throws SQLException

      Constructs a new RowSetDynaClass for the specified ResultSet. The property names corresponding to column names in the result set will be lower cased.

      If limit</code> is not less than 0, max <code>limit number of rows will be copied into the list.
      Parameters:
      resultSet - The result set to be wrapped
      limit - The maximum for the size of the result.
      Throws:
      NullPointerException - if resultSet is null
      SQLException - if the metadata for this result set cannot be introspected

  • Method Details

    • copy

      protected void copy(ResultSet resultSet) throws SQLException

      Copy the column values for each row in the specified ResultSet into a newly created DynaBean, and add this bean to the list of DynaBeans that will later by returned by a call to getRows().

      Parameters:
      resultSet - The ResultSet whose data is to be copied
      Throws:
      SQLException - if an error is encountered copying the data

    • createDynaBean

      protected DynaBean createDynaBean()

      Create and return a new DynaBean instance to be used for representing a row in the underlying result set.

      Returns:
      A new DynaBean instance

    • getRows

      public List<DynaBean> getRows()

      Gets a List containing the DynaBeans that represent the contents of each Row from the ResultSet that was the basis of this RowSetDynaClass instance. These DynaBeans are disconnected from the database itself, so there is no problem with modifying the contents of the list, or the values of the properties of these DynaBeans. However, it is the application's responsibility to persist any such changes back to the database, if it so desires.

      Returns:
      A List of DynaBean instances

    • createDynaProperty

      protected DynaProperty createDynaProperty(ResultSetMetaData metadata, int i) throws SQLException

      Factory method to create a new DynaProperty for the given index into the result set metadata.

      Parameters:
      metadata - is the result set metadata
      i - is the column index in the metadata
      Returns:
      the newly created DynaProperty instance
      Throws:
      SQLException - If an error occurs accessing the SQL metadata

    • getColumnName

      protected String getColumnName(String name)
      Gets the table column name for the specified property name.
      Parameters:
      name - The property name
      Returns:
      The column name (which can be different if the lowerCase option is used).

    • getDynaProperties

      public DynaProperty[] getDynaProperties()

      Gets an array of PropertyDescriptor for the properties currently defined in this DynaClass. If no properties are defined, a zero-length array will be returned.

      Specified by:
      getDynaProperties in interface DynaClass
      Returns:
      the set of properties for this DynaClass

    • getDynaProperty

      public DynaProperty getDynaProperty(String name)

      Gets a property descriptor for the specified property, if it exists; otherwise, return null.

      Specified by:
      getDynaProperty in interface DynaClass
      Parameters:
      name - Name of the dynamic property for which a descriptor is requested
      Returns:
      The descriptor for the specified property
      Throws:
      IllegalArgumentException - if no property name is specified

    • getName

      public String getName()

      Gets the name of this DynaClass (analogous to the getName()</code> method of <code>java.lang.Class, which allows the same DynaClass implementation class to support different dynamic classes, with different sets of properties.

      Specified by:
      getName in interface DynaClass
      Returns:
      the name of the DynaClass

    • getObject

      protected Object getObject(ResultSet resultSet, String name) throws SQLException
      Gets a column value from a ResultSet for the specified name.
      Parameters:
      resultSet - The result set
      name - The property name
      Returns:
      The value
      Throws:
      SQLException - if an error occurs

    • introspect

      protected void introspect(ResultSet resultSet) throws SQLException

      Introspect the metadata associated with our result set, and populate the properties</code> and <code>propertiesMap instance variables.

      Parameters:
      resultSet - The resultSet whose metadata is to be introspected
      Throws:
      SQLException - if an error is encountered processing the result set metadata

    • loadClass

      protected Class<?> loadClass(String className) throws SQLException

      Loads and returns the Class of the given name. By default, a load from the thread context class loader is attempted. If there is no such class loader, the class loader used to load this class will be utilized.

      Parameters:
      className - The name of the class to load
      Returns:
      The loaded class
      Throws:
      SQLException - if an exception was thrown trying to load the specified class

    • newInstance

      public DynaBean newInstance() throws IllegalAccessException, InstantiationException

      Instantiate and return a new DynaBean instance, associated with this DynaClass. NOTE - This operation is not supported, and throws an exception.

      Specified by:
      newInstance in interface DynaClass
      Returns:
      A new DynaBean instance
      Throws:
      IllegalAccessException - if the Class or the appropriate constructor is not accessible
      InstantiationException - if this Class represents an abstract class, an array class, a primitive type, or void; or if instantiation fails for some other reason

    • setUseColumnLabel

      public void setUseColumnLabel(boolean useColumnLabel)
      Sets whether the column label or name should be used for the property name.
      Parameters:
      useColumnLabel - true if the column label should be used, otherwise false