package com.revolsys.jdbc.io;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.annotation.PreDestroy;
import com.revolsys.collection.ResultPager;
import com.revolsys.io.FileUtil;
import com.revolsys.jdbc.JdbcConnection;
import com.revolsys.jdbc.JdbcUtils;
import com.revolsys.record.Record;
import com.revolsys.record.RecordFactory;
import com.revolsys.record.query.Query;
import com.revolsys.record.schema.RecordDefinition;
import com.revolsys.util.Booleans;
public class JdbcQueryResultPager implements ResultPager<Record> {
private JdbcConnection connection;
/** The number of pages. */
private int numPages;
/** The total number of results. */
private int numResults;
/** The current page number. */
private int pageNumber = -1;
/** The number of objects in a page. */
private int pageSize = 10;
private final Query query;
private RecordDefinition recordDefinition;
private RecordFactory recordFactory;
private JdbcRecordStore recordStore;
/** The objects in the current page. */
private List<Record> results;
private ResultSet resultSet;
private final String sql;
private PreparedStatement statement;
public JdbcQueryResultPager(final JdbcRecordStore recordStore,
final Map<String, Object> properties, final Query query) {
final boolean autoCommit = Booleans.getBoolean(properties.get("autoCommit"));
this.connection = recordStore.getJdbcConnection(autoCommit);
this.recordFactory = recordStore.getRecordFactory();
this.recordStore = recordStore;
this.query = query;
final String tableName = query.getTypeName();
this.recordDefinition = query.getRecordDefinition();
if (this.recordDefinition == null) {
this.recordDefinition = recordStore.getRecordDefinition(tableName);
query.setRecordDefinition(this.recordDefinition);
}
this.sql = JdbcUtils.getSelectSql(query);
}
@Override
@PreDestroy
public void close() {
JdbcUtils.close(this.statement, this.resultSet);
FileUtil.closeSilent(this.connection);
this.connection = null;
this.recordFactory = null;
this.recordStore = null;
this.recordDefinition = null;
this.results = null;
this.resultSet = null;
this.statement = null;
}
@Override
protected void finalize() throws Throwable {
super.finalize();
close();
}
/**
* Get the index of the last object in the current page.
*
* @return The index of the last object in the current page.
*/
@Override
public int getEndIndex() {
if (this.pageNumber == getNumPages()) {
return getNumResults();
} else {
return (this.pageNumber + 1) * this.pageSize;
}
}
/**
* Get the list of objects in the current page.
*
* @return The list of objects in the current page.
*/
@Override
public List<Record> getList() {
if (this.results == null) {
throw new IllegalStateException("The page number must be set using setPageNumber");
}
return this.results;
}
/**
* Get the page number of the next page.
*
* @return Thepage number of the next page.
*/
@Override
public int getNextPageNumber() {
return this.pageNumber + 2;
}
/**
* Get the number of pages.
*
* @return The number of pages.
*/
@Override
public int getNumPages() {
return this.numPages + 1;
}
/**
* Get the total number of results returned.
*
* @return The total number of results returned.
*/
@Override
public int getNumResults() {
return this.numResults;
}
/**
* Get the page number of the current page. Index starts at 1.
*
* @return The page number of the current page.
*/
@Override
public int getPageNumber() {
return this.pageNumber + 1;
}
/**
* Get the number of objects to display in a page.
*
* @return The number of objects to display in a page.
*/
@Override
public int getPageSize() {
return this.pageSize;
}
/**
* Get the page number of the previous page.
*
* @return Thepage number of the previous page.
*/
@Override
public int getPreviousPageNumber() {
return this.pageNumber;
}
public Query getQuery() {
return this.query;
}
public RecordDefinition getRecordDefinition() {
return this.recordDefinition;
}
public RecordFactory getRecordFactory() {
return this.recordFactory;
}
public JdbcRecordStore getRecordStore() {
return this.recordStore;
}
protected String getSql() {
return this.sql;
}
/**
* Get the index of the first object in the current page. Index starts at 1.
*
* @return The index of the first object in the current page.
*/
@Override
public int getStartIndex() {
if (getNumResults() == 0) {
return 0;
} else {
return this.pageNumber * this.pageSize + 1;
}
}
/**
* Check to see if there is a next page.
*
* @return True if there is a next page.
*/
@Override
public boolean hasNextPage() {
return this.pageNumber < getNumPages();
}
/**
* Check to see if there is a previous page.
*
* @return True if there is a previous page.
*/
@Override
public boolean hasPreviousPage() {
return this.pageNumber > 0;
}
private void initResultSet() {
if (this.resultSet == null) {
try {
this.statement = this.connection.prepareStatement(this.sql, ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_READ_ONLY);
this.statement.setFetchSize(this.pageSize);
this.resultSet = JdbcQueryIterator.getResultSet(this.recordDefinition, this.statement,
this.query);
this.resultSet.last();
this.numResults = this.resultSet.getRow();
} catch (final SQLException e) {
JdbcUtils.close(this.statement, this.resultSet);
throw new RuntimeException("Error executing query:" + this.sql, e);
}
}
}
public boolean isClosed() {
return this.recordStore == null;
}
/**
* Check to see if this is the first page.
*
* @return True if this is the first page.
*/
@Override
public boolean isFirstPage() {
return this.pageNumber == 0;
}
/**
* Check to see if this is the last page.
*
* @return True if this is the last page.
*/
@Override
public boolean isLastPage() {
return this.pageNumber == getNumPages();
}
protected void setNumResults(final int numResults) {
this.numResults = numResults;
}
/**
* Set the current page number.
*
* @param pageNumber The current page number.
*/
@Override
public void setPageNumber(final int pageNumber) {
if (pageNumber > getNumPages()) {
this.pageNumber = getNumPages() - 1;
} else if (pageNumber <= 0) {
this.pageNumber = 0;
} else {
this.pageNumber = pageNumber - 1;
}
updateResults();
}
@Override
public void setPageNumberAndSize(final int pageSize, final int pageNumber) {
if (pageNumber <= 0) {
this.pageNumber = 0;
} else {
this.pageNumber = pageNumber - 1;
}
this.pageSize = pageSize;
updateNumPages();
updateResults();
}
/**
* Set the number of objects per page.
*
* @param pageSize The number of objects per page.
*/
@Override
public void setPageSize(final int pageSize) {
this.pageSize = pageSize;
updateNumPages();
updateResults();
}
protected void setResults(final List<Record> results) {
this.results = results;
}
protected void updateNumPages() {
this.numPages = Math.max(0, (getNumResults() - 1) / getPageSize());
}
/**
* Update the cached results for the current page.
*/
protected void updateResults() {
this.results = new ArrayList<>();
try {
initResultSet();
if (this.pageNumber != -1 && this.resultSet != null) {
if (this.resultSet.absolute(this.pageNumber * this.pageSize + 1)) {
int i = 0;
do {
final Record object = JdbcQueryIterator.getNextRecord(this.recordStore,
this.recordDefinition, this.recordDefinition.getFields(), this.recordFactory,
this.resultSet);
this.results.add(object);
i++;
} while (this.resultSet.next() && i < this.pageSize);
}
}
} catch (final SQLException e) {
this.connection.getException("updateResults", this.sql, e);
} catch (final RuntimeException e) {
close();
} catch (final Error e) {
close();
}
}
}