Category: java

  • How to read the files placed in WEB-INF from JSF

    Reading files from WEB-INF in JSF

    This no different than reading files from a Servlet except it involves a extra step of getting ServletContext from FacesContext

    FacesContext context = FacesContext.getCurrentInstance();
    ExternalContext externalContext = context.getExternalContext();
    ServletContext sc = (ServletContext)externalContext.getContext();
    String sc.getRealPath("/WEB-INF/somefile.xml");
    

    Here we are getting the path to the file but you could read it if you like.

  • UnsatisfiedLinkError: javaxpcomglue.dll: Can’t find dependent libraries

    While playing around with JavaXPCOM I have run into couple issues. I am running on window 7 64 bit.

    When trying to initialize my GRE (Gecko Runtime Environment) I got following exception

    Exception in thread "main" java.lang.UnsatisfiedLinkError: D:\xulrunner-sdk\bin\javaxpcomglue.dll: Can't find dependent libraries
    	at java.lang.ClassLoader$NativeLibrary.load(Native Method)
    	at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1803)
    	at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1699)
    	at java.lang.Runtime.load0(Runtime.java:770)
    	at java.lang.System.load(System.java:1003)
    	at org.mozilla.xpcom.internal.JavaXPCOMMethods.registerJavaXPCOMMethods(JavaXPCOMMethods.java:57)
    	at org.mozilla.xpcom.internal.MozillaImpl.initialize(MozillaImpl.java:48)
    	at org.mozilla.xpcom.Mozilla.initialize(Mozilla.java:668)
    	at SampleBroswer.init(SampleBroswer.java:69)
    	at SampleBroswer.main(SampleBroswer.java:45)
    

    What is strange on my other dev machine same configuration I don’t have this problem, very strange.

    Problem is that the file mozcrt19.dll can’t be found. So what I did is that I copied that file from xulrunner-sdk\bin to my C:\Windows\SysWOW64 folder and that fixed the problem. Still little puzzled over why my other machine is not throwing this exception.

  • Use argument in EL expression

    There is couple ways about doing that, you could use JBoss EL expression implementation they support method calls with parameters check out Seam, or use similar approach as @digitaljoel suggested.
    This is what I created for that purpose, you can call static and static methods, not a great solution but it does the job.

        
              Hello Panel    
          
    

    @Util is just an alias to com.mycomp.util where

    **Example 2**

                        
            #{t:call(session, 'org.apache.catalina.session.StandardSessionFacade', 'removeAttribute', t:params(t:param(item,'')))}      
        
    

    t:call, t:params, t:param are function defined in project-taglib.xml as so

        	
    		call
    		util.Functions
    		java.lang.Object call(java.lang.Object, java.lang.String, java.lang.String, java.lang.Object[])
    	
    	
    		param
    		.util.Functions
    		java.lang.String param(java.lang.Object, java.lang.String)
    		
    	
    	
    		params
    		util.Functions
    		java.lang.Object[] params(java.lang.String)
    		
    

    Here is the implementation

        package mycompany.web.util;
    
    import java.beans.XMLDecoder;
    import java.beans.XMLEncoder;
    import java.io.BufferedOutputStream;
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.ObjectOutputStream;
    import java.io.StringWriter;
    import java.lang.reflect.Array;
    import java.lang.reflect.InvocationTargetException;
    import java.lang.reflect.Method;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.List;
    
    import javax.el.MethodNotFoundException;
    
    
    public class Functions {
    	
    	private  static HashMap alliasMap;
    	static{
    		alliasMap=new HashMap();
    		alliasMap.put("@DateUtil", "com.americanbanksystems.compliance.util.DateUtil");
    		//Match anything following the dot(.)
    		alliasMap.put("@Util.*", "com.americanbanksystems.compliance.util");
    		
    		alliasMap.put("@Application.*", "com.americanbanksystems.compliance.application");
    		
    	}
    	
    
    
    	
    	public static String param(Object obj, String cls) {	
    		//make sure that passed in object is not null
    		if(obj==null){
    			obj="";
    		}
    	
    		ByteArrayOutputStream baut=new ByteArrayOutputStream();
    		XMLEncoder encoder=new XMLEncoder( baut );
    		//Bug in the JDK
    		//http://bugs.sun.com/bugdatabase/view_bug.do;jsessionid=c993c9a3160fd7de44075a2a1fa?bug_id=6525396
    		if(obj instanceof java.sql.Timestamp){
    			Date o = new Date(((java.sql.Timestamp)obj).getTime());
    			obj=o;
    		}		
    		//Checking if this is possible 
    		if(String.class.isAssignableFrom(obj.getClass())){
    			//removed trailing +" " because it was causing indexOf return invalid value
    			//Unknown side effects
    			obj=FacesUtil.get(obj.toString());			
    		}
    			encoder.writeObject( obj );
    		encoder.close();
    		return new String(baut.toByteArray());
    	}
    	
    	private static Object decode(String str){
    		ByteArrayInputStream bais=new ByteArrayInputStream(str.getBytes());
    		XMLDecoder decoder=new XMLDecoder(bais);
    		return decoder.readObject();
    	}
    	
    	public static Object[] params(String str){
    		// (?<=)\s*(?=)\\s*(?=-1){
    			String subpackage=qualifiedClassname;
    			String originalClass=qualifiedClassname;
    			//Split at the dot
    			boolean isPackageAllias=false;
    			String[] sp=subpackage.split("\\.");	
    			if(sp.length>1){
    				subpackage=sp[0]+".*";
    				isPackageAllias=true;
    			}
    			if(alliasMap.containsKey(subpackage)){
    				String value = alliasMap.get(subpackage);
    				if(isPackageAllias){
    					qualifiedClassname=subpackage.replace(sp[0], value);
    					qualifiedClassname=qualifiedClassname.replace(".*", originalClass.replace(sp[0],""));
    				}else{
    					qualifiedClassname=value;
    				}
    			}else{
    				throw new IllegalArgumentException("Allias name '"+qualifiedClassname+"' not found");
    			}
    		}
    		Class clazz;
    		try {
    			clazz = Class.forName(qualifiedClassname);
    			//Find method by methodName,Argument Types
    			Class[] argumentTypes=new Class[methodArguments.length];	
    
    			for(int i=0;i -1) {
    					String arg = methodArguments[i].toString();
    					arg = arg.substring(2, arg.length());
    					try {
    						int outchar = Integer.parseInt(arg, 16);
    						if (Character.isDefined(outchar)) {
    							methodArguments[i] = String.valueOf((char) outchar);
    						}
    					} catch (NumberFormatException nfe) {
    						// Suppress error and continue assuming this is a regular string
    					}
    				}
    			}
    			
    			Method methodToInvoke = null;
    			try{
    				methodToInvoke  = clazz.getMethod(methodName, argumentTypes);
    			}catch(NoSuchMethodException nsm){//Find by method name/ argument count
    				for (Method method : clazz.getMethods()) {
    					if (method.getName().equals(methodName)  && method.getParameterTypes().length == methodArguments.length) {
    						if (null == owningObject) {
    							owningObject = clazz.newInstance();
    						}
    						methodToInvoke=method;
    						break;
    					}
    				}
    			}
    		
    			if(methodToInvoke!=null){								
    				return methodToInvoke.invoke(owningObject, methodArguments);
    			}else{
    				throw new InstantiationException("method not found :" + methodName);	
    			}
    
    		} catch (ClassNotFoundException e) {
    			e.printStackTrace();
    		} catch (IllegalArgumentException e) {
    			e.printStackTrace();
    		} catch (IllegalAccessException e) {
    			e.printStackTrace();
    		} catch (InvocationTargetException e) {
    			e.printStackTrace();
    		} catch (InstantiationException e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
    
    
    	public static void main(String[] arg) {
    		// StringBuffer buff=new StringBuffer();
    		// buff.append("Gregs init");
    		// Functions.call(java.lang.Class, T, java.lang.String, java.lang.String, java.lang.Object...)
    		/*
    		 * Functions.call(StringBuffer.class, buff, "java.lang.StringBuffer","append"," Init ");
    		 * Functions.call(StringBuffer.class, buff, "java.lang.StringBuffer","append"," greg ");
    		 * System.out.println("output="+ buff);
    		 */
    
    		//#{t:call(null, ".util.DateUtil", "normalizeDate", t:parametize(editRiskActionPlan.riskActionPlan.completionDate,",","java.lang.Object"))}
    	//	c(call(null, "util.DateUtil", "normalizeDate", new Date()));
    		
    		//	#{t:parametize(editRiskActionPlan.riskActionPlan.completionDate,",","java.lang.Object")}
    		//parametize((new Date()).toString(),",","java.lang.Object");
    		Date a=new Date();
    		
    		Date b=new Date();
    		
    		String rawString=param((Date)b, Date.class.toString() );					
    		//System.out.println(rawString);
    		
    		//Replaced=#{t:call("Gregs ' car", 'java.lang.String', 'replace', t:params( parameter ))}
    		
    		String paramA=param("\\u0027","");
    		String paramB=param("\\u0022","");
    		String params=paramA+paramB;
    		String in="I need to ' have a replaced single quote with double";
    		String out=(String)call(in, "java.lang.String", "replace", params(params));
    		
    		System.out.println(out);
    		
    		
    		/*
    		Object[] obj=params(rawString);
    		for(Object o:obj){
    			System.out.println(o);
    		}
    		//c(call(null, "@DateUtil", "normalizeDate", obj));
    		
    		*/
    		
    	}
    
    }
    

    I hope this helps, btw this was copied/pasted from my project so not sure if I missed anything.

  • TabWidget demo project

    Sorry it took little longer than expected, run in some issues with cupcake (SDK 1.5)
    I have attached a Demo project for all interested with  some screenshots and modified .project for TabWidget Project(fixes cupcake problem ref http://groups.google.com/group/android-developers/browse_thread/thread/5537ae10e4143240) if you use eclipse.

    1. My env:
    Eclipse Version: 3.4.2
    Android SDK 1.5
    Windows

    2.After you import the TabWidgedDemo project you will probably need to fix your buildpath.
    Make sure to add TabWidet as a reference to TabWidgedDemo.

    3.In TabWidged project you will need to update the .project file otherwise you will get Verify error when deploying to the device.

    If you have any questions let me know, I hope you enjoy the project, more improvements to come

    Download tabwidgetdemo for eclipse

  • Carme GPS Tracker for Android

    My frist Android app, this is simple GPS tracker program that let us record our tracks, store  and share them.

    This project uses my custom TabWidget for Android.

    Main features

    • Record
    • Playback
    • Share via Email (Google Earth)
    • Share via Twitter  (in progress)
    • Exporting to SD Card
    • Tagging (in progress)

    I use icon from http://www.dryicons.com , love their methodology give the little guys an edge by providing free high quality designs.

    Screenshots

    [nggallery id=2]

    To Come

    Here are some other features that I will implement soon

    • Altitude profiler
    • Photos
    • Profiles

    Download Carme source code

  • Custom Android Tabs

    Due to limitation of Android Tab component I created a custom TabWidget that I am using in couple different projects already. The widget allows us to  add custom background and use custom icons, tabs   can be Top/Bottom aligned.

    Currently tabs can launch new Activity and  Dialog , when starting new Activity we can use  “startActivityForResult” so our tab will get a notification when other activity have finished.

    (more…)