File	Doc	Category	Size	Date	Package
ReflectionUtils.java	API Doc	Apache Lucene 2.1.0	6666	Wed Feb 14 10:46:04 GMT 2007	org.apache.lucene.gdata.utils

ReflectionUtils

• java.lang.Object

Fields Summary

Constructors Summary

Methods Summary
public static boolean	canCreateInstance(java.lang.Class clazz) This method calls {@link Class#newInstance()} to get a new instance. Use with care! param clazz - the class to instantiate return true if an instance could be created, otherwise false; if(clazz == null) return false; if(clazz.isPrimitive()) clazz = getPrimitiveWrapper(clazz); try{ Object o = clazz.newInstance(); return o != null; }catch (Throwable e) { return false; }
public static boolean	extendsType(java.lang.Class typeToCheck, java.lang.Class superType) Check if the given type extends a given super type param typeToCheck - type supposed to extend an specific type param superType - the type to be extended by the type to check return true if and only if the super type is above in the type hierarchy of the given type, otherwise false if (typeToCheck == null) return false; if (typeToCheck.equals(Object.class)) return false; if (typeToCheck.equals(superType)) return true; return extendsType(typeToCheck.getSuperclass(),superType);
public static T	getDefaultInstance(java.lang.Class clazz) param the type of the class to instantiate param clazz - class object of the type return a new instance of T if(clazz == null) throw new ReflectionException("class must not be null"); try{ Constructor constructor = clazz.getConstructor(new Class[]{}); return (T) constructor.newInstance(new Object[]{}); }catch (Exception e) { throw new ReflectionException("can not instantiate type of class "+clazz.getName(),e); }
public static final java.lang.Class	getPrimitiveWrapper(java.lang.Class primitive) Returns the wrapper type for the given primitive type. Wrappers can be easily instantiated via reflection and will be boxed by the VM param primitive - the primitive type return - the corresponding wrapper type if(primitive == null ) throw new ReflectionException("primitive must not be null"); if(!primitive.isPrimitive()) throw new ReflectionException("given class is not a primitive"); if (primitive == Integer.TYPE) return Integer.class; if (primitive == Float.TYPE) return Float.class; if (primitive == Long.TYPE) return Long.class; if (primitive == Short.TYPE) return Short.class; if (primitive == Byte.TYPE) return Byte.class; if (primitive == Double.TYPE) return Double.class; if (primitive == Boolean.TYPE) return Boolean.class; return primitive;
public static boolean	hasDesiredConstructor(java.lang.Class type, java.lang.Class[] parameter) param type - the type to check param parameter - the constructor parameter return true if and only if the type has a visible constructor with the desired parameters try{ return type.getConstructor(parameter) != null; }catch (Exception e) { return false; }
public static boolean	implementsType(java.lang.Class typeToCheck, java.lang.Class superType) Check if the given type implements a given super type param typeToCheck - type supposed to implement an interface param superType - the interface to be implemented by the type to check return true if and only if the super type is above in the type hierarchy of the given type, otherwise false if(superType == null) return false; if(!superType.isInterface()) return false; if (typeToCheck == null) return false; if (typeToCheck.equals(Object.class)) return false; if (typeToCheck.equals(superType)) return true; Class[] interfaces = typeToCheck.getInterfaces(); for (int i = 0; i < interfaces.length; i++) { if (implementsType(interfaces[i], superType)) return true; } return implementsType(typeToCheck.getSuperclass(),superType);
public static boolean	isTypeOf(java.lang.Class typeToCheck, java.lang.Class superType) This method combines the extendsType and implementsType and checks interfaces and classes param typeToCheck - type supposed to extend / implement an specific type param superType - the type to be extended / implemented by the type to check return true if and only if the super type is above in the type hierarchy of the given type, otherwise false return extendsType(typeToCheck,superType)||implementsType(typeToCheck,superType);