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GroovyResult - Groovy scripts as a view

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Here's the code of the actual GroovyResult. This is a verbose version, with a lot of error checking.

• source code

  Code Block
  java java title GroovyResult.java
  public class GroovyResult implements Result { public final static String GROOVY_DIR_NAME = "groovy"; private final static Logger logger = Logger.getLogger(GroovyResult.class); //our groovy source file name private String file; //a groovy shell private GroovyShell shell; //our parsed script private Script script; //the outputstream that will replace the 'out' in our groovy stream private OutputStream out; //directory containing groovy scripts private String scriptDirectory; /* * (non-Javadoc) * * @see com.opensymphony.xwork.Result#execute(com.opensymphony.xwork.ActionInvocation) */ public void execute(ActionInvocation inv) { //check the scriptDirectory - if it doesn't exists, use the default one //WEBAPP + Groovy files directory if (scriptDirectory == null) { //not pretty, but this allows us to get the app root directory String base = ServletActionContext.getServletContext().getRealPath( "/"); //if for some reason (.war, apache connector, ..) we can't get the // base path if (base == null) { logger .warn("Could not translate the virtual path \"/\" to set the default groovy script directory"); return; } scriptDirectory = base + GROOVY_DIR_NAME; //issue a warning that this directory should NOT be world readable // !! logger .warn("Please make sure your script directory is NOT world readable !"); } // first of all, make sure our groovy file exists, is readable, and is // an actual file File groovyFile = new File(scriptDirectory, file); if (!groovyFile.exists()) { //log an error and return logger.warn("Could not find destination groovy file: " + groovyFile.getAbsolutePath()); return; } if (!groovyFile.isFile()) { //log an error and return logger.warn("Destination is not a file: " + groovyFile.getAbsolutePath()); return; } if (!groovyFile.canRead()) { //log an error and return logger.warn("Can not read file: " + groovyFile.getAbsolutePath()); return; } if (logger.isDebugEnabled()) logger.debug("File " + groovyFile.getPath() + " found, going to parse it .."); /* * Here we create a Binding object which we populate with the webwork * stack */ Binding binding = new Binding(); binding.setVariable("context", ActionContext.getContext()); /* * We replace the standard OutputStream with our own, in this case the * OutputStream from our httpResponse */ try { //the out will be stored in an OutputStream out = ServletActionContext.getResponse().getOutputStream(); } catch (IOException e1) { logger.error("Could not open outputstream", e1); } if (out != null){ binding.setVariable("out", out); } else { logger .warn("OutputStream not available, using default System.out instead"); binding.setVariable("out", System.out); } //create a new shell to parse and run our groovy file shell = new GroovyShell(binding); try { //try to parse the script - the returned script could be cached for //performance improvent script = shell.parse(groovyFile); } catch (CompilationFailedException e) { logger.error("Could not parse groovy script", e); return; } catch (IOException e) { logger.error("Error reading groovy script", e); return; } //the binding is set, now run the script Object result = script.run(); if (logger.isDebugEnabled()) { logger.debug("Script " + groovyFile.getName() + " executed, and returned: " + result); } try { out.flush(); } catch (IOException e2) { logger.error("Could not flush the outputstream", e2); } } /** * @return Returns the script. */ public Script getScript() { return script; } /** * @param file * The file to set. */ public void setFile(String file) { this.file = file; } /** * @param out * The out to set. */ public void setOut(OutputStream out) { this.out = out; }

Explanation

The first part of the result is little more than:

• determining the script directory - defaults to MYWEBAPP/groovy/
• checking the file - make sure it exists, is readable, ..

  Note
  Make sure the groovy scripts directory is not world readable !

Binding binding = new Binding();
binding.setVariable("context", ActionContext.getContext());

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