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DataSourceUtil.javaAPI DocGlassfish v2 API5837Sat May 05 19:17:54 BST 2007org.apache.taglibs.standard.tag.common.sql

DataSourceUtil

public class DataSourceUtil extends Object

A simple DataSource utility for the standard DriverManager class. TO DO: need to cache DataSource

author
Justyna Horwat

Fields Summary
private static final String
ESCAPE
private static final String
TOKEN
Constructors Summary
Methods Summary
static javax.sql.DataSourcegetDataSource(java.lang.Object rawDataSource, javax.servlet.jsp.PageContext pc)
If dataSource is a String first do JNDI lookup. If lookup fails parse String like it was a set of JDBC parameters Otherwise check to see if dataSource is a DataSource object and use as is


                                             
         
	 
    
	DataSource dataSource = null;

        if (rawDataSource == null) {
            rawDataSource = Config.find(pc, Config.SQL_DATA_SOURCE);
        }

	if (rawDataSource == null) {
	    return null;
	}

        /*
	 * If the 'dataSource' attribute's value resolves to a String
	 * after rtexpr/EL evaluation, use the string as JNDI path to
	 * a DataSource
	 */
        if (rawDataSource instanceof String) {
            try {
                Context ctx = new InitialContext();
                // relative to standard JNDI root for J2EE app
                Context envCtx = (Context) ctx.lookup("java:comp/env");
                dataSource = (DataSource) envCtx.lookup((String) rawDataSource);
            } catch (NamingException ex) {
                dataSource = getDataSource((String) rawDataSource);
            }
        } else if (rawDataSource instanceof DataSource) {
            dataSource = (DataSource) rawDataSource;
        } else {
	    throw new JspException(
                Resources.getMessage("SQL_DATASOURCE_INVALID_TYPE"));
	}

	return dataSource;
private static javax.sql.DataSourcegetDataSource(java.lang.String params)
Parse JDBC parameters and setup dataSource appropriately

        DataSourceWrapper dataSource = new DataSourceWrapper();

        String[] paramString = new String[4];
        int escCount = 0; 
        int aryCount = 0; 
        int begin = 0;

        for(int index=0; index < params.length(); index++) {
            char nextChar = params.charAt(index);
            if (TOKEN.indexOf(nextChar) != -1) {
                if (escCount == 0) {
                    paramString[aryCount] = params.substring(begin,index).trim();
                    begin = index + 1;
                    if (++aryCount > 4) {
                        throw new JspTagException(
                            Resources.getMessage("JDBC_PARAM_COUNT"));
                    }
                }
            }
            if (ESCAPE.indexOf(nextChar) != -1) {
                escCount++;
            }
            else {
                escCount = 0;
            }
        }
        paramString[aryCount] = params.substring(begin).trim();

	// use the JDBC URL from the parameter string
        dataSource.setJdbcURL(paramString[0]);

	// try to load a driver if it's present
        if (paramString[1] != null) {
            try {
                dataSource.setDriverClassName(paramString[1]);
            } catch (Exception ex) {
                throw new JspTagException(
                    Resources.getMessage("DRIVER_INVALID_CLASS",
					 ex.toString()), ex);
            }
	}

	// set the username and password
        dataSource.setUserName(paramString[2]);
        dataSource.setPassword(paramString[3]);

	return dataSource;