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javajspservletsweb.xmlservlet-filters
brain storm
brain storm

Reputation: 31272

filters in Java Servlet not working properly?

I am a beginner in using Java Servlets. I am having some issues with my servlets. my filters are not being applied.

Here is my web.xml:

<web-app>
<display-name>CP130 Assignment 8</display-name>
<filter>
    <description>Filter using XSLT to format servlet response</description>
    <display-name>CP130QuoteTransformFilter</display-name>
    <filter-name>QuoteResponseFormatter</filter-name>
    <filter-class>edu.uw.rgm.web.QuoteTransformFilter</filter-class>
    <init-param>
        <description>HTML transform</description>
        <param-name>html-transform</param-name>
        <param-value>xslt/quote2html.xslt</param-value>
    </init-param>
    <init-param>
        <description>JSON transform</description>
        <param-name>json-transform</param-name>
        <param-value>xslt/quote2json.xslt</param-value>
    </init-param>
    <init-param>
        <description>Plain transform</description>
        <param-name>plain-transform</param-name>
        <param-value>xslt/quote2plain.xslt</param-value>
    </init-param>
</filter>
<servlet>
    <description>Servlet obtaining stock quote from Yahoo Financial Services</description>
    <display-name>CP130QuoteServlet</display-name>
    <servlet-name>StockQuoteJsp</servlet-name>
    <servlet-class>edu.uw.rgm.web.YahooStockQuoteServlet</servlet-class>
    <jsp-file>/Quote.jsp</jsp-file>
</servlet>
<servlet-mapping>
    <servlet-name>StockQuoteJsp</servlet-name>
    <url-pattern>/Quote.jsp</url-pattern>
</servlet-mapping>
<filter-mapping>
    <filter-name>QuoteResponseFormatter</filter-name>
    <servlet-name>StockQuoteJsp</servlet-name>
</filter-mapping>
<filter-mapping>
    <filter-name>QuoteResponseFormatter</filter-name>
    <url-pattern>/Quote.jsp</url-pattern>
</filter-mapping>
<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

I have placed some println statements in the filters I apply for the response. when I run my main app in the console, I see that no print is generated. It probably indicates that my response is not passing through filters. I triple checked the filter names and filter-class and url-patterns and there is no typo in it.

I get the following error:

[WARNING] 
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:297)
    at java.lang.Thread.run(Thread.java:724)
Caused by: java.io.FileNotFoundException: http://localhost:8080/StockQuote/Quote.jsp?symbol=GOOG&rstype=json
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1624)
    at app.QuoteApp.exec(QuoteApp.java:73)
    at app.QuoteApp.main(QuoteApp.java:100)
    ... 6 more
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.820s
[INFO] Finished at: Tue Jun 17 12:49:02 PDT 2014
[INFO] Final Memory: 8M/245M

Does the order of elements in web.xml matter?

why is my filter not applied in response?

Thanks

EDIT:

Here is the latest version of web.xml that I tried. I just moved filter element below servlet element in web.xml I do not any error this time. but again the filter is not applied.

web.xml:

<web-app>
    <display-name>CP130 Assignment 8</display-name>
    <servlet>
        <description>Servlet obtaining stock quote from Yahoo Financial Services</description>
        <display-name>CP130QuoteServlet</display-name>
        <servlet-name>StockQuoteJsp</servlet-name>
        <jsp-file>/Quote.jsp</jsp-file>
    </servlet>
    <servlet-mapping>
        <servlet-name>StockQuoteJsp</servlet-name>
        <servlet-class>edu.uw.rgm.web.YahooStockQuoteServlet</servlet-class>
        <url-pattern>/Quote.jsp</url-pattern>
    </servlet-mapping>
    <filter>
        <description>Filter using XSLT to format servlet response</description>
        <display-name>CP130QuoteTransformFilter</display-name>
        <filter-name>QuoteResponseFormatter</filter-name>
        <filter-class>edu.uw.rgm.web.QuoteTransformFilter</filter-class>
        <init-param>
            <description>HTML transform</description>
            <param-name>html-transform</param-name>
            <param-value>xslt/quote2html.xslt</param-value>
        </init-param>
        <init-param>
            <description>JSON transform</description>
            <param-name>json-transform</param-name>
            <param-value>xslt/quote2json.xslt</param-value>
        </init-param>
        <init-param>
            <description>Plain transform</description>
            <param-name>plain-transform</param-name>
            <param-value>xslt/quote2plain.xslt</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>QuoteResponseFormatter</filter-name>
        <servlet-name>StockQuoteJsp</servlet-name>
    </filter-mapping>
    <filter-mapping>
        <filter-name>QuoteResponseFormatter</filter-name>
        <url-pattern>/Quote.jsp</url-pattern>
    </filter-mapping>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

Upvotes: 0

Views: 873

Answers (1)

Braj
Braj

Reputation: 46881

As per the web-app_2_3.dtd

<!ELEMENT servlet (icon?, servlet-name, display-name?, description?,
(servlet-class|jsp-file), init-param*, load-on-startup?, run-as?, security-role-ref*)>

Use either <jsp-file> or <servlet-class> under <servlet>. Since JSP is finally converted to Servlet class so you can't use both at a time.

<servlet>
    <description>Servlet obtaining stock quote from Yahoo Financial Services</description>
    <display-name>CP130QuoteServlet</display-name>
    <servlet-name>StockQuoteJsp</servlet-name>
    <servlet-class>edu.uw.rgm.web.YahooStockQuoteServlet</servlet-class>
    <jsp-file>/Quote.jsp</jsp-file>
</servlet>

As per the exception FileNotFoundException, Is Quote.jsp placed directly under the webapp/webcontent folder?

EDIT

For a specific URL pattern either you can redirect it to a JSP page or a Servlet class.

In below case the Servlet will be called whenever Quote.jsp is passed in the URL.

<servlet>
    <description>Servlet obtaining stock quote from Yahoo Financial Services</description>
    <display-name>CP130QuoteServlet</display-name>
    <servlet-name>StockQuoteJsp</servlet-name>
    <servlet-class>edu.uw.rgm.web.YahooStockQuoteServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>StockQuoteJsp</servlet-name>
    <url-pattern>/Quote.jsp</url-pattern>
</servlet-mapping>

Upvotes: 1

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