com.nhncorp.neptune.client.procedure
Class CharSequenceCompiler<T>

java.lang.Object
  com.nhncorp.neptune.client.procedure.CharSequenceCompiler<T>

public class CharSequenceCompiler<T>
extends java.lang.Object

Compile a String or other CharSequence, returning a Java Class instance that may be instantiated. This class is a Facade around JavaCompiler for a narrower use case, but a bit easier to use.

To compile a String containing source for a Java class which implements MyInterface:

 ClassLoader classLoader = MyClass.class.getClassLoader(); // optional; null is also OK 
 List<Diagnostic> diagnostics = new ArrayList<Diagnostic>(); // optional; null is also OK
 JavaStringCompiler<Object> compiler = new JavaStringCompiler<MyInterface>(classLoader,
       null);
 try {
    Class<MyInterface> newClass = compiler.compile("com.mypackage.NewClass",
          stringContaininSourceForNewClass, diagnostics, MyInterface);
    MyInterface instance = newClass.newInstance();
    instance.someOperation(someArgs);
 } catch (JavaStringCompilerException e) {
    handle(e);
 } catch (IllegalAccessException e) {
    handle(e);
 }
 

The source can be in a String, StringBuffer, or your own class which implements CharSequence. If you implement your own, it must be thread safe (preferably, immutable.)

Author:

David J. Biesack

Constructor Summary

CharSequenceCompiler(java.lang.ClassLoader loader, java.lang.Iterable<java.lang.String> options)
Construct a new instance which delegates to the named class loader.

Method Summary

java.util.Map<java.lang.String,java.lang.Class<T>>	compile(java.util.Map<java.lang.String,java.lang.CharSequence> classes, javax.tools.DiagnosticCollector<javax.tools.JavaFileObject> diagnosticsList) Compile multiple Java source strings and return a Map containing the resulting classes.
java.lang.Class<T>	compile(java.lang.String qualifiedClassName, java.lang.CharSequence javaSource, javax.tools.DiagnosticCollector<javax.tools.JavaFileObject> diagnosticsList, java.lang.Class<?>... types) Compile Java source in javaSource and return the resulting class.
java.lang.ClassLoader	getClassLoader()
java.lang.Class<T>	loadClass(java.lang.String qualifiedClassName) Load a class that was generated by this instance or accessible from its parent class loader.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CharSequenceCompiler

public CharSequenceCompiler(java.lang.ClassLoader loader,
                            java.lang.Iterable<java.lang.String> options)

Construct a new instance which delegates to the named class loader.

Parameters:

loader - the application ClassLoader. The compiler will look through to this // class loader for dependent classes

options - The compiler options (such as "-target" "1.5"). See the usage for javac

Throws:

java.lang.IllegalStateException - if the Java compiler cannot be loaded.

Method Detail

compile

public java.lang.Class<T> compile(java.lang.String qualifiedClassName,
                                  java.lang.CharSequence javaSource,
                                  javax.tools.DiagnosticCollector<javax.tools.JavaFileObject> diagnosticsList,
                                  java.lang.Class<?>... types)
                           throws CharSequenceCompilerException,
                                  java.lang.ClassCastException

Compile Java source in javaSource and return the resulting class.

Thread safety: this method is thread safe if the javaSource and diagnosticsList are isolated to this thread.

Parameters:

qualifiedClassName - The fully qualified class name.

javaSource - Complete java source, including a package statement and a class, interface, or annotation declaration.

diagnosticsList - Any diagnostics generated by compiling the source are added to this collector.

types - zero or more Class objects representing classes or interfaces that the resulting class must be assignable (castable) to.

Returns:

a Class which is generated by compiling the source

Throws:

CharSequenceCompilerException - if the source cannot be compiled - for example, if it contains syntax or semantic errors or if dependent classes cannot be found.

java.lang.ClassCastException - if the generated class is not assignable to all the optional types.

compile

public java.util.Map<java.lang.String,java.lang.Class<T>> compile(java.util.Map<java.lang.String,java.lang.CharSequence> classes,
                                                                  javax.tools.DiagnosticCollector<javax.tools.JavaFileObject> diagnosticsList)
                                                           throws CharSequenceCompilerException

Compile multiple Java source strings and return a Map containing the resulting classes.

Thread safety: this method is thread safe if the classes and diagnosticsList are isolated to this thread.

Parameters:

classes - A Map whose keys are qualified class names and whose values are the Java source strings containing the definition of the class. A map value may be null, indicating that compiled class is expected, although no source exists for it (it may be a non-public class contained in one of the other strings.)

diagnosticsList - Any diagnostics generated by compiling the source are added to this list.

Returns:

A mapping of qualified class names to their corresponding classes. The map has the same keys as the input classes; the values are the corresponding Class objects.

Throws:

CharSequenceCompilerException - if the source cannot be compiled

loadClass

public java.lang.Class<T> loadClass(java.lang.String qualifiedClassName)
                             throws java.lang.ClassNotFoundException

Load a class that was generated by this instance or accessible from its parent class loader. Use this method if you need access to additional classes compiled by compile(), for example if the primary class contained nested classes or additional non-public classes.

Parameters:

qualifiedClassName - the name of the compiled class you wish to load

Returns:

a Class instance named by qualifiedClassName

Throws:

java.lang.ClassNotFoundException - if no such class is found.

getClassLoader

public java.lang.ClassLoader getClassLoader()

Returns:

This compiler's class loader.