package org.jtester.bytecode.reflector.helper;
import static java.util.Arrays.asList;
import java.lang.reflect.Field;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.jtester.bytecode.reflector.FieldAccessor;
import org.jtester.exception.NoSuchFieldRuntimeException;
@SuppressWarnings({ "rawtypes" })
public final class FieldHelper {
/**
* jTester method to search for a field starting from the specified class
* and going up the hierarchy until the field is found or the {@link Object}
* class is reached.
*
* @param cls
* the class from which to start
* @param name
* the field name
* @return the {@link Field} found
* @throws NoSuchFieldException
* if the field cannot be found within the specified class
* hierarchy.
*/
public static Field getField(Class cls, String name) {
while (cls != Object.class) {
try {
Field field = cls.getDeclaredField(name);
field.setAccessible(true);
return field;
} catch (NoSuchFieldException e) {
cls = cls.getSuperclass();
}
}
throw new NoSuchFieldRuntimeException("No such field: " + name);
}
/**
* 设置实例target的字段值
*
* @param target
* @param fieldName
* @param fieldValue
*/
public static void setFieldValue(Object target, String fieldName, Object fieldValue) {
if (target == null) {
throw new RuntimeException("the target object can't be null.");
}
FieldAccessor accessor = new FieldAccessor(target.getClass(), fieldName);
accessor.set(target, fieldValue);
}
public static void setFieldValue(Object target, Field field, Object fieldValue) {
if (target == null) {
throw new RuntimeException("the target object can't be null.");
}
if (field == null) {
throw new RuntimeException("the field can't be null.");
}
boolean isAccessible = field.isAccessible();
try {
field.setAccessible(true);
field.set(target, fieldValue);
} catch (Exception e) {
String info = String.format("to set field[%s] value into target[%s] error.", field.getName(), target
.getClass().getName());
throw new RuntimeException(info, e);
} finally {
field.setAccessible(isAccessible);
}
}
/**
* Returns the value of the given field (may be private) in the given object<br>
* 获得对象obj的属性名为fieldname的字段值
*
* @param target
* The object containing the field, null for static fields
* @param fieldName
* The field, not null
* @return The value of the given field in the given object
*/
public static Object getFieldValue(Object target, String fieldName) {
if (target == null) {
throw new RuntimeException("the target object can't be null.");
}
FieldAccessor accessor = new FieldAccessor(target.getClass(), fieldName);
Object o = accessor.get(target);
return o;
}
public static Object getStaticFieldValue(Class claz, String fieldName) {
if (claz == null) {
throw new RuntimeException("the target class can't be null.");
}
FieldAccessor accessor = new FieldAccessor(claz, fieldName);
Object o = accessor.getStatic();
return o;
}
public static Object getFieldValue(Object target, Field field) {
if (target == null) {
throw new RuntimeException("the target object can't be null.");
}
if (field == null) {
throw new RuntimeException("the field can't be null.");
}
boolean isAccessible = field.isAccessible();
try {
field.setAccessible(true);
Object o = field.get(target);
return o;
} catch (Exception e) {
String info = String.format("to get field[%s] value from target[%s] error.", field.getName(), target
.getClass().getName());
throw new RuntimeException(info, e);
} finally {
field.setAccessible(isAccessible);
}
}
/**
* 返回类所有的字段（包括父类的）<br>
* Gets all fields of the given class and all its super-classes.
*
* @param clazz
* The class
* @return The fields, not null
*/
public static List<Field> getAllFields(final Class clazz) {
List<Field> result = new ArrayList<Field>();
if (clazz == null || clazz.equals(Object.class)) {
return result;
}
Class type = clazz;
while (type != Object.class && type != null) {
// add all fields of this class
Field[] declaredFields = type.getDeclaredFields();
result.addAll(asList(declaredFields));
type = type.getSuperclass();
}
return result;
}
/**
* Returns all declared fields of the given class that are assignable from
* the given type.
*
* @param clazz
* The class to get fields from, not null
* @param type
* The type, not null
* @param isStatic
* True if static fields are to be returned, false for non-static
* @return A list of Fields, empty list if none found
*/
public static Set<Field> getFieldsAssignableFrom(Class clazz, Type type) {
Set<Field> fieldsOfType = new HashSet<Field>();
List<Field> allFields = getAllFields(clazz);
for (Field field : allFields) {
boolean isAssignFrom = ClazzHelper.isAssignable(type, field.getGenericType());
if (isAssignFrom) {
fieldsOfType.add(field);
}
}
return fieldsOfType;
}
/**
* Returns the fields in the given class that have the exact given type. The
* class's superclasses are also investigated.
*
* @param clazz
* The class to get the field from, not null
* @param type
* The type, not null
* @param isStatic
* True if static fields are to be returned, false for non-static
* @return The fields with the given type
*/
public static Set<Field> getFieldsOfType(Class clazz, Type type) {
Set<Field> fields = new HashSet<Field>();
List<Field> allFields = getAllFields(clazz);
for (Field field : allFields) {
boolean isTypeEquals = field.getType().equals(type);
if (isTypeEquals) {
fields.add(field);
}
}
return fields;
}
}