FileDocCategorySizeDatePackage
ChainedParamReader.javaAPI DocApache Axis 1.44527Sat Apr 22 18:57:28 BST 2006org.apache.axis.utils.bytecode

ChainedParamReader

public class ChainedParamReader extends Object
Description: In ParamReader class, user can not get inherited method parameter from the class they passed in. This is done because of performance. This class is intended to setup the inheritant chain. If the method could not be found in the derived class, it will try to search it from super class, if not in the immedidate super class it will search super class's super class, until it reaches the root which is java.lang.Object. This is not an eager load since it only start searching the super class when it is asked to User: pengyu Date: Sep 6, 2003 Time: 11:43:24 PM

Fields Summary
private List
chain
private List
clsChain
private Map
methodToParamMap
Constructors Summary
public ChainedParamReader(Class cls)
Process a given class's parameter names

param
cls the class which user wants to get parameter info from
throws
IOException


                             
         
        ParamReader reader = new ParamReader(cls);
        chain.add(reader);
        clsChain.add(cls);
Methods Summary
public java.lang.String[]getParameterNames(java.lang.reflect.Constructor ctor)
return the names of the declared parameters for the given constructor. If we cannot determine the names, return null. The returned array will have one name per parameter. The length of the array will be the same as the length of the Class[] array returned by Constructor.getParameterTypes().

param
ctor
return
array of names, one per parameter, or null

        //there is no need for the constructor chaining.
        return ((ParamReader) chain.get(0)).getParameterNames(ctor);
public java.lang.String[]getParameterNames(java.lang.reflect.Method method)
return the names of the declared parameters for the given method. If we cannot determine the names in the current class, we will try to search its parent class until we reach java.lang.Object. If we still can not find the method we will return null. The returned array will have one name per parameter. The length of the array will be the same as the length of the Class[] array returned by Method.getParameterTypes().

param
method
return
String[] array of names, one per parameter, or null

        //go find the one from the cache first
        if (methodToParamMap.containsKey(method)) {
            return (String[]) methodToParamMap.get(method);
        }

        String[] ret = null;
        for (Iterator it = chain.iterator(); it.hasNext();) {
            ParamReader reader = (ParamReader) it.next();
            ret = reader.getParameterNames(method);
            if (ret != null) {
                methodToParamMap.put(method, ret);
                return ret;
            }
        }
        //if we here, it means we need to create new chain.
        Class cls = (Class) clsChain.get(chain.size() - 1);
        while (cls.getSuperclass() != null) {
            Class superClass = cls.getSuperclass();
            try {
                ParamReader _reader = new ParamReader(superClass);
                chain.add(_reader);
                clsChain.add(cls);
                ret = _reader.getParameterNames(method);
                if (ret != null) { //we found it so just return it.
                    methodToParamMap.put(method, ret);
                    return ret;
                }
            } catch (IOException e) {
                //can not find the super class in the class path, abort here
                return null;
            }
        }
        methodToParamMap.put(method, ret);
        return null;