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package com.fasterxml.jackson.jr.ob.impl;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Map;
import java.util.TreeMap;
import com.fasterxml.jackson.jr.ob.JSON;
import com.fasterxml.jackson.jr.ob.impl.POJODefinition.Prop;
import com.fasterxml.jackson.jr.ob.impl.POJODefinition.PropBuilder;
/**
* Helper class that jackson-jr uses by default to introspect POJO properties
* (represented as {@link POJODefinition}) to build general POJO readers
* (deserializers) and writers (serializers).
*
* Note that most of the usage is via {@link ValueReaderLocator} and
* {@link ValueWriterLocator}
*
* @since 2.11
*/
public class BeanPropertyIntrospector
{
protected final static Prop[] NO_PROPS = new Prop[0];
private final static BeanPropertyIntrospector INSTANCE = new BeanPropertyIntrospector();
public BeanPropertyIntrospector() { }
public static BeanPropertyIntrospector instance() { return INSTANCE; }
public POJODefinition pojoDefinitionForDeserialization(JSONReader r, Class pojoType) {
return _construct(pojoType, r.features());
}
public POJODefinition pojoDefinitionForSerialization(JSONWriter w, Class pojoType) {
return _construct(pojoType, w.features());
}
/*
/**********************************************************************
/* Internal methods
/**********************************************************************
*/
private POJODefinition _construct(Class beanType, int features)
{
Map propsByName = new TreeMap();
_introspect(beanType, propsByName, features);
Constructor defaultCtor = null;
Constructor stringCtor = null;
Constructor longCtor = null;
for (Constructor ctor : beanType.getDeclaredConstructors()) {
Class[] argTypes = ctor.getParameterTypes();
if (argTypes.length == 0) {
defaultCtor = ctor;
} else if (argTypes.length == 1) {
Class argType = argTypes[0];
if (argType == String.class) {
stringCtor = ctor;
} else if (argType == Long.class || argType == Long.TYPE) {
longCtor = ctor;
} else {
continue;
}
} else {
continue;
}
}
final int len = propsByName.size();
Prop[] props;
if (len == 0) {
props = NO_PROPS;
} else {
props = new Prop[len];
int i = 0;
for (PropBuilder builder : propsByName.values()) {
props[i++] = builder.build();
}
}
return new POJODefinition(beanType, props, defaultCtor, stringCtor, longCtor);
}
private static void _introspect(Class currType, Map props,
int features)
{
if (currType == null || currType == Object.class) {
return;
}
// First, check base type
_introspect(currType.getSuperclass(), props, features);
final boolean noStatics = JSON.Feature.INCLUDE_STATIC_FIELDS.isDisabled(features);
// then public fields (since 2.8); may or may not be ultimately included
// but at this point still possible
for (Field f : currType.getDeclaredFields()) {
if (!Modifier.isPublic(f.getModifiers())
|| f.isEnumConstant() || f.isSynthetic()) {
continue;
}
// Only include static members if (a) inclusion feature enabled and
// (b) not final (cannot deserialize final fields)
if (Modifier.isStatic(f.getModifiers())
&& (noStatics || Modifier.isFinal(f.getModifiers()))) {
continue;
}
_propFrom(props, f.getName()).withField(f);
}
// then get methods from within this class
for (Method m : currType.getDeclaredMethods()) {
final int flags = m.getModifiers();
// 13-Jun-2015, tatu: Skip synthetic, bridge methods altogether, for now
// at least (add more complex handling only if absolutely necessary)
if (Modifier.isStatic(flags)
|| m.isSynthetic() || m.isBridge()) {
continue;
}
Class argTypes[] = m.getParameterTypes();
if (argTypes.length == 0) { // getter?
// getters must be public to be used
if (!Modifier.isPublic(flags)) {
continue;
}
Class resultType = m.getReturnType();
if (resultType == Void.class) {
continue;
}
String name = m.getName();
if (name.startsWith("get")) {
if (name.length() > 3) {
name = decap(name.substring(3));
_propFrom(props, name).withGetter(m);
}
} else if (name.startsWith("is")) {
if (name.length() > 2) {
// May or may not be used, but collect for now all the same:
name = decap(name.substring(2));
_propFrom(props, name).withIsGetter(m);
}
}
} else if (argTypes.length == 1) { // setter?
// Non-public setters are fine if we can force access, don't yet check
// let's also not bother about return type; setters that return value are fine
String name = m.getName();
if (!name.startsWith("set") || name.length() == 3) {
continue;
}
name = decap(name.substring(3));
_propFrom(props, name).withSetter(m);
}
}
}
private static PropBuilder _propFrom(Map props, String name) {
PropBuilder prop = props.get(name);
if (prop == null) {
prop = Prop.builder(name);
props.put(name, prop);
}
return prop;
}
private static String decap(String name) {
char c = name.charAt(0);
char lowerC = Character.toLowerCase(c);
if (c != lowerC) {
// First: do NOT lower case if more than one leading upper case letters:
if ((name.length() == 1)
|| !Character.isUpperCase(name.charAt(1))) {
char chars[] = name.toCharArray();
chars[0] = lowerC;
return new String(chars);
}
}
return name;
}
}