CleverGWT

From PlcWiki

Contents 1 Installation 2 ClvListGrid - Extension of ListGrid 3 SecuredServiceServlet 4 JettyLauncher 5 DocumentServlet and UploadServlet 6 StringUtil 7 ParserCSV 8 BCrypt

Installation

Repository: svn+ssh://username@oko.clever.cz

Path: /java/CleverGWT

...gwt.xml:

 <inherits name="cz.clever.gwt.ext.Module" />

ClvListGrid - Extension of ListGrid

Simplification of CRUD usage:

ListGrid grid = new ClvListGrid(new ClvListGrid.Delegate() {
 
			@Override
			public void executeUpdate(ClvListGridResponse response) {
				// Map<String, Object> reqMap = response.getRequestMap();
				// response.response(...
			}
 
			@Override
			public void executeRemove(ClvListGridResponse response) {}
 
			@Override
			public void executeFetch(ClvListGridResponse response) {}
 
			@Override
			public void executeAdd(ClvListGridResponse response) {}
 
			@Override
			public DataSourceField[] createFields() {
				return new DataSourceField[] { new DataSourceTextField("Field Name") };
			}
		});

Note: If you are implementing executeRemove/Add/Fetch you must call response.response(...). Not in executeUpdate.

SecuredServiceServlet

Benefits:

• Request without GWT permutation header will be blocked (potential CSRF attack)
• Authorization check before the servlet methods are called from client (methods must be annotated as Secured)

 public class MyGWTServiceImpl extends SecuredServiceServlet implements ...
 
 @Override
 protected boolean isInRole(String user, String method, Object value, Integer position) {
		// check for permission
 }

JettyLauncher

Allow you to set custom logging and configuration.

Example of startup arguments:

-startupUrl Entrypoint.html ... -server cz.clever.gwt.ext.server.JettyLauncher  ...

Inside a class:

 wac.setConfigurationClasses(new String[] { 
        "org.mortbay.jetty.webapp.WebInfConfiguration", 
        "org.mortbay.jetty.plus.webapp.EnvConfiguration",//jetty-env 
        "org.mortbay.jetty.plus.webapp.Configuration", //web.xml 
        "org.mortbay.jetty.webapp.JettyWebXmlConfiguration",//jettyWeb 
 });

DocumentServlet and UploadServlet

HttpServlet solution for uploading and downloading documents.

Example of upload servlet configuration:

 <servlet>
		<servlet-name>MaterialUpload</servlet-name>
		<servlet-class>cz.clever.cct.gwt.app.server.MyUploadServlet</servlet-class>
		<init-param>
	        <param-name>repository</param-name>
			<param-value>/tmp</param-value>
        </init-param>
        <init-param>
	        <param-name>maxMemSize</param-name>
			<param-value>2147483646</param-value>
        </init-param>
        <init-param>
	        <param-name>maxFileSize</param-name>
			<param-value>2147483646</param-value>
        </init-param>
	</servlet>

StringUtil

java.util.StringTokenizer is prohibited in the GWT client side. Here is my substitution:

 StringUtil.tokenizer("Jirka, Petr, Honza", ",", new ValueCallback() {
 
	@Override
	public void execute(String token) {
		// Your code
	}
 });

Way how to build delimiter separated string from collection:

 ToString<MaterialOption> toStr = new ToString<MaterialOption>() {
 
	@Override
	public String get(MaterialOption obj) { //make a token from object
		return obj.toString();
		// or if you want: return obj == null? null:obj.getOptionString();
	}
 };
 // collection with filling of course
 Collection<MaterialOption> myCollection = new ArrayList<MaterialOption>();
 
 String result = StringUtil.toString(myCollection, ", ", toStr);

ParserCSV

 new ParserCSV(new ParserCSV.Delegate() {
 
			@Override
			public void token(String token, int position) {
				// working with parsed tokens
			}
 
			@Override
			public String getPath() { return "MyTable.csv"; }
 
			@Override
			public String getDelimeter() { return ";";}
 
			@Override
			public String getCharsetName() { return "UTF-16"; }
 });

BCrypt

String hashed = BCrypt.hashpw("password", BCrypt.gensalt());
boolean verified = BCrypt.checkpw("password", hashed);