package org.nutz.json.entity;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.nutz.json.JsonException;
import org.nutz.json.JsonField;
import org.nutz.json.JsonFormat;
import org.nutz.json.ToJson;
import org.nutz.lang.Lang;
import org.nutz.lang.Mirror;
import org.nutz.lang.Strings;
import org.nutz.lang.born.Borning;
import org.nutz.lang.born.BorningException;
import org.nutz.lang.util.Callback;
import org.nutz.lang.util.Callback3;
/**
* 记录一个Java如何映射 JSON 字符串的规则
*
* @author zozoh(zozohtnt@gmail.com)
*/
public class JsonEntity {
private List<JsonEntityField> fields;
private Map<String, JsonEntityField> fieldMap = new HashMap<String, JsonEntityField>();
private Borning<?> borning;
private BorningException err;
private Map<String, Integer> typeParams; // 如果本类型是范型，存放范型标识的下标
private Method toJsonMethod;
public JsonEntity(Mirror<?> mirror) {
// 处理范型
Type type = mirror.getActuallyType();
typeParams = new HashMap<String, Integer>();
if (type instanceof ParameterizedType) {
ParameterizedType pmType = (ParameterizedType) type;
int i = 0;
for (Type pmA : pmType.getActualTypeArguments()) {
typeParams.put(pmA.toString(), i++);
}
}
// 开始解析
Field[] flds = mirror.getFields();
fields = new ArrayList<JsonEntityField>(flds.length);
for (Field fld : flds) {
JsonEntityField ef = JsonEntityField.eval(mirror, fld);
if (null == ef) {
continue;
}
fields.add(ef);
fieldMap.put(ef.getName(), ef);
}
for (Method m : mirror.getMethods()) {
final JsonField jf = m.getAnnotation(JsonField.class);
// 忽略方法
if (null == jf || jf.ignore())
continue;
// 如果有，尝试作新的 Entity
final Method method = m;
Callback<Method> whenError = new Callback<Method>() {
// 给定方法即不是 getter 也不是 setter，靠！玩我!
public void invoke(Method m) {
throw Lang.makeThrow(JsonException.class,
"JsonField '%s' should be getter/setter pair!",
m);
}
};
Callback3<String, Method, Method> whenOk = new Callback3<String, Method, Method>() {
public void invoke(String name, Method getter, Method setter) {
// 防止错误
if (null == getter || null == setter || Strings.isBlank(name)) {
throw Lang.makeThrow(JsonException.class,
"JsonField '%s' should be getter/setter pair!",
method);
}
// 加入字段表
JsonEntityField ef = JsonEntityField.eval(Strings.sBlank(jf.value(), name),
getter,
setter);
fields.add(ef);
fieldMap.put(ef.getName(), ef);
}
};
Mirror.evalGetterSetter(m, whenOk, whenError);
}
try {
borning = mirror.getBorning();
}
catch (BorningException e) {
err = e;
}
Class<? extends Object> klass = mirror.getType();
ToJson tj = klass.getAnnotation(ToJson.class);
String myMethodName = Strings.sNull(null == tj ? null : tj.value(), "toJson");
try {
/*
* toJson()
*/
try {
Method myMethod = klass.getMethod(myMethodName);
if (!myMethod.isAccessible())
myMethod.setAccessible(true);
toJsonMethod = myMethod;
}
/*
* toJson(JsonFormat fmt)
*/
catch (NoSuchMethodException e1) {
try {
Method myMethod = klass.getMethod(myMethodName, JsonFormat.class);
if (!myMethod.isAccessible())
myMethod.setAccessible(true);
toJsonMethod = myMethod;
}
catch (NoSuchMethodException e) {}
}
}
catch (Exception e) {
throw Lang.wrapThrow(e);
}
}
public List<JsonEntityField> getFields() {
return fields;
}
public Object born() {
if (null == borning)
throw err;
return borning.born(new Object[0]);
}
public JsonEntityField getField(String name) {
return fieldMap.get(name);
}
public Method getToJsonMethod() {
return toJsonMethod;
}
}