com.caucho.es
Class Script

java.lang.Object
  |
  +--com.caucho.es.Script

public abstract class Script
extends java.lang.Object

The Script object represents a compiled JavaScript. Executing it is thread safe. To create a Script, use the Parser class to parse a file.

Java programs set JavaScript Global properties by adding objects to a HashMap. Typically you will at least assign the 'File' and the 'out' objects. The running script will see these objects as properties of the Global object. If you set the 'out' object, the script can use the bare bones 'writeln("foo")' to write to 'out'.


 HashMap map = new HashMap();
 map.put("File", Vfs.lookup());
 map.put("out", System.out);
 map.put("myObject", myObject);

 script.execute(map, null);
 

You can also make any Java object be the global prototype. Essentially, the effect is similar to the HashMap technique, but it's a little simpler.

Scripts are thread-safe. Multiple script instances can safely execute in separate threads. Script.execute creates the entire JavaScript global object hierarchy fresh for each execution. So one Script execution cannot interfere with another, even by doing evil things like modifying the Object prototype.

Of course, wrapped Java objects shared by script invocations must still be synchronized.


Field Summary
protected  Path classDir
           
protected  Path scriptPath
           
 
Constructor Summary
Script()
           
 
Method Summary
 java.lang.String execute(java.util.HashMap properties, java.lang.Object proto)
          Execute the script; the main useful entry.
 ScriptClosure executeClosure(java.util.HashMap properties, java.lang.Object proto)
          Execute the program, returning a closure of the global state.
 void export(ESObject dest, ESObject src)
          Internal method to export objects.
 com.caucho.java.LineMap getLineMap()
          Returns the map from source file line numbers to the generated java line numbers.
abstract  ESGlobal initClass(Global resin)
          Internal method implemented by the generated script for initialization.
 ESGlobal initClass(Global resin, ESObject global)
          Internal method to initialize the script after loading it.
 boolean isModified()
          Internal method to check if the source files have changed.
 void setClassDir(Path classDir)
          Internal method to set the work directory for generated *.java and *.class.
 void setScriptPath(Path scriptPath)
          Internal method to set the script search path for imported scripts.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

scriptPath

protected Path scriptPath

classDir

protected Path classDir
Constructor Detail

Script

public Script()
Method Detail

isModified

public boolean isModified()
Internal method to check if the source files have changed.

setScriptPath

public void setScriptPath(Path scriptPath)
Internal method to set the script search path for imported scripts.

setClassDir

public void setClassDir(Path classDir)
Internal method to set the work directory for generated *.java and *.class.

getLineMap

public com.caucho.java.LineMap getLineMap()
Returns the map from source file line numbers to the generated java line numbers.

execute

public java.lang.String execute(java.util.HashMap properties,
                                java.lang.Object proto)
                         throws java.lang.Exception
Execute the script; the main useful entry.

Calling programs can make Java objects available as properties of the global object by creating a property hash map or assigning a global prototype.


 HashMap map = new HashMap();
 map.put("File", Vfs.lookup());
 map.put("out", System.out);
 map.put("myObject", myObject);
 script.execute(map, null);
 
Then the JavaScript can use the defined objects:

 out.println(myObject.myMethod("foo"));
 
Parameters:
properties - A hash map of global properties.
proto - Global prototype. Gives the script direct access to the java methods of the object.
Returns:
String value of the last expression, like the JavaScript eval. This is useful only for testing.

executeClosure

public ScriptClosure executeClosure(java.util.HashMap properties,
                                    java.lang.Object proto)
                             throws java.lang.Exception
Execute the program, returning a closure of the global state. executeClosure will execute the global script.

Later routines can then call into the closure. The closure is not thread-safe. So only a single thread may execute the closure.

Parameters:
properties - A hash map of global properties.
proto - Global prototype. Gives the script direct access to the java methods of the object.
Returns:
the closure

initClass

public ESGlobal initClass(Global resin,
                          ESObject global)
                   throws java.lang.Exception
Internal method to initialize the script after loading it.

initClass

public abstract ESGlobal initClass(Global resin)
                            throws java.lang.Exception
Internal method implemented by the generated script for initialization.

export

public void export(ESObject dest,
                   ESObject src)
            throws java.lang.Exception
Internal method to export objects.