/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
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* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
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* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
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* Foundation" must not be used to endorse or promote products derived
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* ====================================================================
*
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package org.apache.commons.jelly.tags.sql;
import java.sql.*;
import java.util.*;
import javax.sql.DataSource;
import javax.servlet.jsp.jstl.sql.Result;
import javax.servlet.jsp.jstl.sql.SQLExecutionTag;
import org.apache.commons.jelly.JellyContext;
import org.apache.commons.jelly.JellyException;
import org.apache.commons.jelly.TagSupport;
import org.apache.commons.jelly.XMLOutput;
import org.apache.commons.jelly.tags.Resources;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* <p>Tag handler for <Query> in JSTL.
*
* @author Hans Bergsten
* @author Justyna Horwat
*/
public class QueryTag extends SqlTagSupport {
/** The Log to which logging calls will be made. */
private static final Log log = LogFactory.getLog(QueryTag.class);
/*
* The following properties take expression values, so the
* setter methods are implemented by the expression type
* specific subclasses.
*/
protected int maxRows = -1;
protected boolean maxRowsSpecified;
protected int startRow;
/*
* Instance variables that are not for attributes
*/
private Connection conn;
//*********************************************************************
// Constructor and initialization
public QueryTag() {
}
//*********************************************************************
// Accessor methods
/**
* The index of the first row returned can be
* specified using startRow.
*/
public void setStartRow(int startRow) {
this.startRow = startRow;
}
/**
* Query result can be limited by specifying
* the maximum number of rows returned.
*/
public void setMaxRows(int maxRows) {
this.maxRows = maxRows;
this.maxRowsSpecified = true;
}
//*********************************************************************
// Tag logic
/**
* <p>Execute the SQL statement, set either through the <code>sql</code>
* attribute or as the body, and save the result as a variable
* named by the <code>var</code> attribute in the scope specified
* by the <code>scope</code> attribute, as an object that implements
* the Result interface.
*
* <p>The connection used to execute the statement comes either
* from the <code>DataSource</code> specified by the
* <code>dataSource</code> attribute, provided by a parent action
* element, or is retrieved from a JSP scope attribute
* named <code>javax.servlet.jstl.sql.dataSource</code>.
*/
public void doTag(XMLOutput output) throws Exception {
if (!maxRowsSpecified) {
Object obj = context.getVariable("org.apache.commons.jelly.sql.maxRows");
if (obj != null) {
if (obj instanceof Integer) {
maxRows = ((Integer) obj).intValue();
}
else if (obj instanceof String) {
try {
maxRows = Integer.parseInt((String) obj);
}
catch (NumberFormatException nfe) {
throw new JellyException(
Resources.getMessage("SQL_MAXROWS_PARSE_ERROR", (String) obj),
nfe);
}
}
else {
throw new JellyException(Resources.getMessage("SQL_MAXROWS_INVALID"));
}
}
}
Result result = null;
String sqlStatement = null;
log.debug( "About to lookup connection" );
try {
conn = getConnection();
/*
* Use the SQL statement specified by the sql attribute, if any,
* otherwise use the body as the statement.
*/
if (sql != null) {
sqlStatement = sql;
}
else {
sqlStatement = getBodyText();
}
if (sqlStatement == null || sqlStatement.trim().length() == 0) {
throw new JellyException(Resources.getMessage("SQL_NO_STATEMENT"));
}
/*
* We shouldn't have a negative startRow or illegal maxrows
*/
if ((startRow < 0) || (maxRows < -1)) {
throw new JellyException(Resources.getMessage("PARAM_BAD_VALUE"));
}
/*
* Note! We must not use the setMaxRows() method on the
* the statement to limit the number of rows, since the
* Result factory must be able to figure out the correct
* value for isLimitedByMaxRows(); there's no way to check
* if it was from the ResultSet.
*/
if ( log.isDebugEnabled() ) {
log.debug( "About to execute query: " + sqlStatement );
}
ResultSet rs = null;
if ( hasParameters() ) {
PreparedStatement ps = conn.prepareStatement(sqlStatement);
setParameters(ps);
rs = ps.executeQuery();
}
else {
Statement statement = conn.createStatement();
rs = statement.executeQuery(sqlStatement);
}
result = new ResultImpl(rs, startRow, maxRows);
context.setVariable(var, result);
}
catch (SQLException e) {
throw new JellyException(sqlStatement + ": " + e.getMessage(), e);
}
finally {
if (conn != null && !isPartOfTransaction) {
try {
conn.close();
}
catch (SQLException e) {
} // Not much we can do
conn = null;
}
clearParameters();
}
}
}