我想创建以下策略模式与Factory结合,但我希望它是类型安全的.到目前为止我做了以下事情:
public interface Parser<T> {
public Collection<T> parse(ResultSet resultSet);
}
public class AParser implements Parser<String> {
@Override
public Collection<String> parse(ResultSet resultSet) {
//perform parsing, get collection
Collection<String> cl = performParsing(resultSet); //local private method
return cl;
}
}
public class ParserFactory {
public enum ParserType {
APARSER
}
public static <T> Parser<T> createParser(ParserType parserType) {
Parser<?> parser = null;
switch (parserType) {
case APARSER:
parser = new AParser();
break;
}
//unchecked cast happens here
return (Parser<T>) parser;
}
}
public class …我创建了以下@RepositoryRestResource查询,我想为其余的api创建动态查询.所以基本上我想做的事情如下:
myHost/myApp/data/search/all?name=me&age=20&address=myhome&etc=etc
所以我在下面创建了查询:
@Query("Select t from Data t " +
"where " +
"t.name like :name AND " +
"t.age = :age AND " +
"t.address = :address AND " +
"t.etc= :etc"
@RestResource(path = "all", rel = "all")
Page findByAll(@Param("name") String name, @Param("age") String age,
@Param("address") String address, @Param("etc") String etc, Page page);
显然其中一些可能尚未输入.有没有办法在存储库中定义默认值？所以例如我想要name一个默认值%.
我不完全确定这种方法对于我想要做的是正确的,所以欢迎任何替代建议.
我有一个特定的任务，我按计划的时间间隔运行。基本上，我在 JFrame 中的标签上显示相机提要。但是，当我退出 JFrame 时，应用程序似乎在运行。我怎样才能阻止它？我已经剥离了代码的细节，只留下了相关的部分
public class TaskCLass extends JFrame {
JPanel p;
JLabel l;
Timer timer;
public TaskCLass() {
p = new JPanel();
l = new JLabel("Window");
add(p);
p.add(l);
setSize(700, 600);
this.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
System.out.println(e);
timer.purge();
timer.cancel();
System.exit(1);
}
public void windowClosed(WindowEvent e) {
System.out.println(e);
timer.purge();
timer.cancel();
System.exit(1);
}
});
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
startTask();
}
public static void main(String[] args) {
new TaskCLass();
}
public void startTask() {
TimerTask t = new TimerTask() { …我在mongoDB中有以下集合
{ _id, startTime, duration }
因此,基本的想法是摄像机可以找到人,一旦它检测到一个人就会保存startTime,一旦一个人消失,就可以节省持续时间.因此,该实体基本上说"一个人出现在X时间,并且在摄像机范围内为Y毫秒".startTime和duration都是数值.
所以,我想执行各种查询,例如:1.给我每月/每年的人数2.给我每月的人数,持续时间> 5000毫秒
等等
虽然我对MongoDB很新,但我对聚合框架有点麻烦,所以如果有人让我知道如何进行如上所述的查询,我会很感激,以便获得某种先发制人的想法. .
编辑:
好吧,我做了几次尝试,但没有运气.现在我的对象有这样的形式:
{
"_id" : ObjectId("52de407c75895eaf5ea99715"),
"startTime" : "new Date('02 01 2011 08:36:54')",
"duration" : 27000
}
我正在尝试这个查询:
db.collection.aggregate(
{$project : {
year : {$year : "$startTime"}
}},
{$group : {
_id : {year : "$year"},
count : {$sum : 1}
}}
)
但我得到以下例外:
Error occurred in performing aggregation
Command 'aggregate' failed: exception: can't convert from BSON type String to Date (response: { "errmsg" : "exception: can't convert …假设我想要编辑一个现有实体,该实体具有一系列值,这些值也是可选值的一部分.例如
var preSelectedLanguages = [
{id: 2, iso: "de"},
{id: 3, iso: "fr"}
]
var languages = [
{id: 1, iso: "en"},
{id: 2, iso: "de"},
{id: 3, iso: "fr"},
{id: 4, iso: "it"},
{id: 5, iso: "us"}
]
我的ui-select指令类似于:
<ui-select multiple ng-model="preSelectedLanguages">
<ui-select-match placeholder="Select language...">
{{$item.iso}}
</ui-select-match>
<ui-select-choices repeat="l in languages track by language.id">
{{language.iso}}
</ui-select-choices>
</ui-select>
然而ui-select-choices选项列表似乎无法删除重复项,即使我已经使用过track by language.id.
知道如何正确地做到这一点？
让我们假设我有以下实体(省略了注释/ getter设置器):
@Entity
public class Topic {
@Id
private Long id;
private String title;
private String text;
@OneToMany(mappedBy = "topic", cascade = CascadeType.REMOVE)
private List<Post> posts = new LinkedList();
}
@Entity
public class Post {
@Id
private Long id;
private String text;
@Temporal(TemporalType.DATE)
private Date createdOn;
@Temporal(TemporalType.DATE)
private Date updatedOn;
@ManyToOne
private Topic topic;
}
我想运行一个JPQL基本上Topics根据最新的排序的查询Post.
所以我创建的查询如下:
select t from Topic t join t.posts p
group by t, p
order by p.updatedOn desc
然而 …
我正在尝试Spring Boot在Weblogic 12.1.3上部署Web应用程序。
从控制台部署时，出现以下错误（在应用程序上）
Message icon - Error Unable to access the selected application.
Message icon - Error String index out of range: 51968
Message icon - Error String index out of range: 51968
Message icon - Error String index out of range: 51968
另一方面，它可以从Intellij IDEA和autodeploy文件夹成功部署。另外，在其他开发机器上，它甚至可以从控制台成功部署，但在其他机器上则不能。
服务器日志上也没有任何错误。
有什么原因的想法吗？
I have a peculiar case where I need to use the Application Server (Weblogic) security context for authentication, but Spring Security for authorization. I am using Spring Boot to create my application.
How can I add a security constraint like follows (which would normally be contained in web.xml):
<security-constraint>
<web-resource-collection>
<web-resource-name>portal</web-resource-name>
<description>This is the protected area of the application.</description>
<url-pattern>/*</url-pattern>
</web-resource-collection>
<auth-constraint>
<description>Requires users to be authenticated but does not require them to be authorized.</description>
<role-name>*</role-name>
</auth-constraint>
<user-data-constraint>
<description>Encryption …我正在尝试实现一个通用 DAO 以在我的项目中使用。到目前为止，我已经实现的代码如下：
基础DAO
public abstract class BaseDAO<T> {
private Class<T> entityClass;
public BaseDAO(Class<T> entityClass) {
this.entityClass = entityClass;
}
protected abstract EntityManager getEntityManager();
public T persist(T entity) {
getEntityManager().persist(entity);
return entity;
}
public T edit(T entity) {
getEntityManager().merge(entity);
return entity;
}
public T remove(T entity) {
getEntityManager().remove(entity);
return entity;
}
public List<T> findAll() {
Query q = getEntityManager().createQuery("SELECT e FROM " + entityClass.getName()
+ " e");
List<T> list = (List<T>) q.getResultList();
return list;
}
public T find(Long id) { …让我们假设我有以下实体:
@Entity
public class Registration {
@ManyToOne
private Student student;
//getters, setters
}
@Entity
public class Student {
private String id;
private String userName;
private String name;
private String surname;
//getters, setters
}
@Projection(name="minimal", types = {Registration.class, Student.class})
public interface RegistrationProjection {
String getUserName();
Student getStudent();
}
我正在尝试创建以下JSON表示,所以当我使用时,http://localhost:8080/api/registrations?projection=minimal我不需要所有用户数据:
{
"_links": {
"self": {
"href": "http://localhost:8080/api/registrations{?page,size,sort,projection}",
}
},
"_embedded": {
"registrations": [
{
"student": {
"userName": "user1"
}
}
],
"_links": {
"self": {
"href": "http://localhost:8080/api/registrations/1{?projection}",
}
}
} …