Java Code Examples for java.lang.reflect.Field#trySetAccessible()

/**
 * 设置目标实体的指定字段的值
 * @param isExact value的类型是否匹配,如果匹配请选择true,速度更快
 * @author Frodez
 * @date 2019-12-29
 */
@SuppressWarnings("deprecation")
@SneakyThrows
public static void set(Class<?> klass, String fieldName, Object target, @Nullable Object value) {
	Assert.notNull(klass, "klass must not be null");
	Assert.notNull(fieldName, "fieldName must not be null");
	Assert.notNull(target, "target must not be null");
	Field field = klass.getDeclaredField(fieldName);
	if (!field.isAccessible()) {
		//暂时使用isAccessible api,因为可以减少判断次数提高性能
		field.trySetAccessible();
	}
	String identifier = StrUtil.concat(klass.getCanonicalName(), DefStr.POINT_SEPERATOR, fieldName);
	MethodHandle handle = SETTER_CACHE.get(identifier);
	if (handle == null) {
		handle = MethodHandles.lookup().unreflectSetter(field);
		SETTER_CACHE.put(identifier, handle);
	}
	handle.invoke(target, value);
}
 

/**
 * 设置目标实体的指定字段的值
 * @param isExact value的类型是否匹配,如果匹配请选择true,速度更快
 * @author Frodez
 * @date 2019-12-29
 */
@SuppressWarnings("deprecation")
@SneakyThrows
public static void set(Field field, Object target, @Nullable Object value) {
	Assert.notNull(field, "field must not be null");
	Assert.notNull(target, "target must not be null");
	if (!field.isAccessible()) {
		//暂时使用isAccessible api,因为可以减少判断次数提高性能
		field.trySetAccessible();
	}
	String identifier = StrUtil.concat(field.getDeclaringClass().getCanonicalName(), DefStr.POINT_SEPERATOR, field.getName());
	MethodHandle handle = SETTER_CACHE.get(identifier);
	if (handle == null) {
		handle = MethodHandles.lookup().unreflectGetter(field);
		GETTER_CACHE.put(identifier, handle);
	}
	handle.invoke(target, value);
}
 

/**
 * 获取目标实体的指定字段
 * @author Frodez
 * @date 2019-12-29
 */
@SuppressWarnings("deprecation")
@SneakyThrows
public static Object get(Class<?> klass, String fieldName, Object target) {
	Assert.notNull(klass, "klass must not be null");
	Assert.notNull(fieldName, "fieldName must not be null");
	Assert.notNull(target, "target must not be null");
	Field field = klass.getDeclaredField(fieldName);
	if (!field.isAccessible()) {
		//暂时使用isAccessible api,因为可以减少判断次数提高性能
		field.trySetAccessible();
	}
	String identifier = StrUtil.concat(klass.getCanonicalName(), DefStr.POINT_SEPERATOR, fieldName);
	MethodHandle handle = GETTER_CACHE.get(identifier);
	if (handle == null) {
		handle = MethodHandles.lookup().unreflectGetter(field);
		GETTER_CACHE.put(identifier, handle);
	}
	return handle.invoke(target);
}
 

/**
 * 获取目标实体的指定字段
 * @author Frodez
 * @date 2019-12-29
 */
@SuppressWarnings("deprecation")
@SneakyThrows
public static Object get(Field field, Object target) {
	Assert.notNull(field, "field must not be null");
	Assert.notNull(target, "target must not be null");
	if (!field.isAccessible()) {
		//暂时使用isAccessible api,因为可以减少判断次数提高性能
		field.trySetAccessible();
	}
	String identifier = StrUtil.concat(field.getDeclaringClass().getCanonicalName(), DefStr.POINT_SEPERATOR, field.getName());
	MethodHandle handle = GETTER_CACHE.get(identifier);
	if (handle == null) {
		handle = MethodHandles.lookup().unreflectGetter(field);
		GETTER_CACHE.put(identifier, handle);
	}
	return handle.invoke(target);
}
 

public <T> void inject(T instance) {
    try {
        Class<?> visitorType = instance.getClass();
        while (!visitorType.equals(Object.class)) {
            for (Field field : visitorType.getDeclaredFields()) {
                if (field.isAnnotationPresent(Inject.class)) {
                    if (Modifier.isStatic(field.getModifiers()))
                        throw new Error("static field must not have @Inject, field=" + Fields.path(field));
                    if (field.trySetAccessible()) {
                        field.set(instance, lookupValue(field));
                    } else {
                        throw new Error("failed to inject field, field=" + Fields.path(field));
                    }
                }
            }
            visitorType = visitorType.getSuperclass();
        }
    } catch (IllegalAccessException e) {
        throw new Error(e);
    }
}
 

@Override
@SuppressWarnings("unchecked")
public Object handleType(ResultSet resultSet, Class<?> type) throws SQLException {
    try {
        var instance = type.getDeclaredConstructor().newInstance();
        var fields = Util.fieldsOf(type);

        var metaData = resultSet.getMetaData();
        for (int i = 1; i <= metaData.getColumnCount(); i++) {
            var columnName = metaData.getColumnLabel(i);

            Field f = findField(fields, columnName);
            if(isNull(f)) {
                LOGGER.debug("There is no field with name {} on Type {}",  columnName, type.getName());
                continue;
            }
            if(f.trySetAccessible()) {
                var handler = TypeHandler.MAP.getOrDefault(f.getType().isEnum() ? "enum" : f.getType().getName(), TypeHandler.MAP.get(Object.class.getName()));
                f.set(instance, handler.handleColumn(resultSet, i, f.getType()));
            } else {
                throw new SQLException("No accessible field " + f.getName() + " On type " + type );
            }
        }
        return instance;
    } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
        throw new SQLException(e);
    }
}
 

private static boolean isPrivateAndNotNullField(Field field, Object bean) throws IllegalArgumentException, IllegalAccessException {
	return Modifier.PRIVATE == field.getModifiers() && field.trySetAccessible() && field.get(bean) != null;
}