让我们得到代码:
def some_function():
with transaction.atomic():
# some code which writes to DB
try:
call_method_which_may_raise_exception()
except KnownException as e:
save_some_data_about_exception_to_database(e)
raise
# other code
我有下面的scala代码,它包含密封的特征和case对象。
sealed trait StudentType {
val studentLevel: String
val code: Int
}
case object UnderGradFull extends StudentType {
val studentLevel = "UGF"
val code = 11
}
case object UnderGradPart extends StudentType {
val studentLevel = "UGP"
val code =
缓慢:
SELECT `m`.`id`,
`h`.`number`,
`h`.`message`,
`h`.`code`,
FROM `members` AS `m`
INNER JOIN `history` AS `h` ON `h`.`memb_id` = `m`.`id`
LEFT JOIN `reads` AS `r` ON `r`.`memb_id` = `m`.`id`
LEFT JOIN `writes` AS `w` ON `w`.`memb_id` = `m`.`id`
WHERE `m`.`
我在azure中创建了一个资源作为CosmosDB的MongoDB api。但是当我添加任何集合时。我得到了下面的错误。 OperationFailure: Retryable writes are not supported. Please disable retryable writes by specifying "retrywrites=false" in the connection string or an equivalent driver specific config., full error: {'ok': 0.0, 'errmsg
[ I am out of ideas I need a to write a code that writes and reads text files within theprocessfiles method and a code that counts and print the total number of borrowers As part of my home I need to write a class that writes and reads text files.
public void
processFiles()throws FileNotFound
我有一些类似的东西:
sealed trait Foo
case class Bar(field: ...) extends Foo
case class Baz(otherField: ...) extends Foo
trait JsonFormat {
implicit val barWrites = Json.writes[Bar]
implicit val barReads = Json.reads[Bar]
implicit val bazWrites = Json.writes[Baz]
implicit val bazReads = Json.reads[B
clas=(input("what class are you in?"))
if clas== 1:# this code works only if the users input is 1
file= open("class1.txt", "a")# this creates a text file named class 1 which is created in the location of this program
file.write(name) # this store/writes the user
拥有
ByteArrayOutputStream b = ...;
//some code under test writes to b
Reader result = (convert b to reader);
IOUtils.contentEqualsIgnoreEOL(expected, result);
如何将ByteArrayOutputStream转换为Reader
我正在试验Scala Play,不明白为什么Null json序列化不能发挥作用。我编写了一个简单的类来封装响应中的数据(ServiceResponse),它返回一个参数可空的字段data,并且还隐含了一个WritesNull,我遗漏了什么?编译器建议编写一个可以工作但感觉很麻烦的Writes[ServiceResponseNull],我想知道是否有一种更简洁的方法来解决这个问题。下面是代码和错误。
// <!-- EDIT -->
// The data I want to transfer
case class Person (name: String, age: Int)
我在空间上遇到麻烦了。如何正确打印输出文件?当我运行我的代码,就像.
这是我的主要方法,并生成输出文件.
main()....{
File stats = new File(statFile);
stats.createNewFile();
// my code here.... the stat values change here.
FileWriter statFileWriter = new FileWriter(stats, true);
BufferedWriter statsOutput = new BufferedWriter(statFileW
关于man工具有两个sync页面:
(1) http://man7.org/linux/man-pages/man1/sync.1.html
NAME
sync - Synchronize cached writes to persistent storage
SYNOPSIS top
sync [OPTION] [FILE]...
DESCRIPTION top
Synchronize cached writes to persistent storage
If one or
我必须跟随bulk_write将数据集中的每个文档插入到集合中。
data = [] # list of dicts/documents
mongo = MongoClient('some_host')
db = mongo['some_db']
collection = db['some_collection']
operations = [UpdateOne({'_id': d['_id']}, {'$set': d}, upsert=True) for d in data]
result =
我有以下EJB单例:
@Singleton
public class MySingleton {
@Lock(LockType.WRITE)
public void doSomethingWrite(){
//code that writes something to DB
}
@Lock(LockType.READ)
public void doSomethingRead(){
//code that READS something from DB
}
@Lock(LockType.READ)
public void doSomethingR
我试图将此模型转换为Json,但始终出现错误“unapply函数找到匹配的未应用参数”。
我试着实现两个不同的编写器来完成这个任务,但两者都不起作用。
这是我的模型:
case class Page[T](
var data: List[T],
var previous: String,
var next: String,
var totalPageCount: Int)(implicit val tWrites: Writes[T])
object Page {
// Both Writters generate an "No apply
我有一段代码,通过为基本特征定义自定义写,尝试自定义一组案例类的JSON序列化。我得到无限的递归/堆栈溢出。
我创建了一个简化的示例--如果有人知道如何修复它,请告诉我。
import play.api.libs.json._
sealed trait Person {
val name: String
}
final case class Teacher(name: String, salary: Int) extends Person
final case class Student(name: String, grade: Int) extends Person
implici
基本上,这是一个将值写入int数组的简单函数。
我想给当前元素赋值,打印它和索引,然后自动增加索引到下一个元素。
然而,自增量顺序的变化使得结果不同.
#include <stdio.h>
int buff[5];
int id;
void write ( )
{
int i;
i = id = 0;
printf("Iter 1\n");
while (i++ < 5) {
buff[id] = id;
printf("writes %d in buff[%d]\n", bu
我只是想知道StringBuffer的具体代码是什么样的。
但我只能找到这样的抽象方法。好吧..。
你能让我知道具体的代码吗?谢谢!
// Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
part of dart.cor
我受到了挑战。我不确定如何在没有jython或cython (或其他IronPython之类的东西)的情况下使用多处理,所以我选择了在我的多核CentOS程序中使用线程。它读取一组文本文件并将其输出到字典(由已定义函数外部的hfreq={}定义)。如果我让它处于睡眠状态,它就会运行(非常慢,似乎是在一个内核上),而且工作得很好。
此外,我不知道如何让它等待,直到两个线程都完成实际输出到文件(除了sleep.time部分,这完全违背了速度的目的)
示例:
hfreq={}
[INSERT TEXT FILE ARRAYS HERE, RESPECTIVELY filenames0[] and f
我应该用什么来代替???,这样代码才能输入check?还是我还应该做点什么?我使用Play为类B、C、D生成JSON,这些类都扩展了A(层),但是试图构建JSON的代码只知道它有A,而不是B、C或D的哪个子类型。
class Layer
object Layer {
implicit val layerWrites = new Writes[Layer] {
def writes(x: Layer) = x match {
case a: CloudLayer => ???
case b: VerticalVisibility =&g
我有个奇怪的问题!我试图为8位windows 3.x位图文件编写颜色表。我只希望文件是灰色的,所以我尝试写bbb0,ggg0,rrr0 256遍r=g=b=1..256
//write greyscale color table
for (int i = 255; i >= 0; i--) {
writeS = (unsigned short)i;
outfile.write ((char*)&writeS,sizeof(char)); // b
outfile.write ((char*)&writeS,sizeof(char)); // g
我生成的JSON的速度,单位可能会有所不同。我有一个SpeedUnit特性和扩展它的类(节、MetersPerSecond、MilesPerHour)。说:“要将您自己的模型转换为JsValues,您必须定义隐式写转换程序并提供它们的作用域。”在大多数地方,我都能做到这一点,但当我有一个类扩展一个特性的时候,我就没有了。我做错了什么?或者我可以或者应该用Enum变体来代替?
// Type mismatch: found (String, SpeedUnit), required (String, Json.JsValueWrapper)
// at 4th line from bottom: