小编Oli*_*ohm的帖子

我正在尝试使用Spring的JdbcTemplate来简化我在Tomcat中部署并连接到Postgres的Java Web服务中的DAO.

我正在关注Spring的文档,我正在尝试在应用程序上下文文件中配置DataSource,如下所示:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd">

  <context:component-scan base-package="com.manta" />

  <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="${driverClassName}"/>
    <property name="url" value="${url}"/>
    <property name="username" value="${username}"/>
    <property name="password" value="${password}"/>
  </bean>

  <context:property-placeholder location="/WEB-INF/db.properties"/>

</beans>

我db.properties在适当的地方有以下文件:

driverClassName=org.postgresql.Driver 
url=jdbc:postgresql://pgprod.ecnext.com:5432/manta
username=my_user_name
password=my_password

当我尝试部署时,我发现以下堆栈跟踪catalina.out:

SEVERE: Context initialization failed
org.springframework.beans.factory.BeanDefinitionStoreException: 
Invalid bean definition with name 'dataSource' defined in ServletContext resource [/WEB-INF/context.xml]: 
Could not resolve placeholder 'driverClassName'
    at org.springframework.beans.factory.config.PlaceholderConfigurerSupport.doProcessProperties(PlaceholderConfigurerSupport.java:209)
    at org.springframework.beans.factory.config.PropertyPlaceholderConfigurer.processProperties(PropertyPlaceholderConfigurer.java:220)
    at org.springframework.beans.factory.config.PropertyResourceConfigurer.postProcessBeanFactory(PropertyResourceConfigurer.java:84)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:681)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:656) …

我有以下服务:

@Service
public class CamelService {

    @Transactional
    public aCamelThing() {

          Camel camel = this.camelRepository.findOne(1);

          System.out.println(camel.getCamelName());  // prints "normalCamel"

          // simple hql set field 'camelName'
          int res = this.camelRepository.updateCamelName(1,"superCamel!");

          Camel camelWithNewName = this.camelRepository.findOne(1);

          System.out.println(camelWithNewName .getCamelName());  // prints "normalCamel" ?!?!?

    } 
}

我知道如何实现第二张println打印的目标:"superCamel!" ？(将第二次调用与新事务分开并不理想).

假设您有以下两个实体,Address和Customer,它们之间具有一对一的映射关系.

@Entity
public class Address {    
    @Id @GeneratedValue
    private Long id;    
    private String street_1;
    private String street_2;    
    private String city;
    private String state;
    private String zipcode;
    private String country;

    @OneToOne(mappedBy = "address")
    private Customer customer;

    //getters, setters, and constructors
}

@Entity
public class Customer {

    @Id @GeneratedValue
    private Long id;  
    private String firstName;
    private String lastName;
    private String email;
    private String phoneNumber;

    @OneToOne @JoinColumn( name = "address_id" )
    private Address address;

    //getters, setters, and constructors
}

另外,我有这两个存储库类:

public interface AddressRepository …

我最近升级到Spring Data MongoDB 1.6.0.RC1,非常好,并实现了MongoDB 2.6(huuurah!)的全文搜索功能.我的问题是:我如何组合Criteria和TextCriteria类来生成复杂的查询？

示例对象模型:

{
  textProperty: "a text that is indexed for full text search",
  language:"en",
  aBooleanProperty: true,
  anIntegerProperty: 1
}

查询:

db.collection({ anIntegerProperty: 1,  $text: { $search: "indexed", $language: "en" } })

那么,如何使用Spring Data MongoDB类编写上述查询？

有一个投影UserProjection,User表有字段 - enable_email布尔值.

@Projection(name = "summary", types = User.class)
public interface UserSummaryProjection {

    String getEmail();
}

访问URL /app/users/{id}?projection=summary按预期显示电子邮件

1. 如何总结投影配置为返回的电子邮件仅enable_email是true？

2. 该配置是否仅影响此预测或适用于User实体的所有预测？

我正在使用Spring Boot并尝试使用Spring Data REST实现实体之间的多对多关系,其中不会Author创建依赖实体的重复项.

给定以下代码,当我发布初始书籍时,与作者一起创建作者,创建书籍,并创建关系(查找表条目).当我使用同一作者发布第二本书时,会创建第二本书,并尝试创建第二位作者,由于对作者姓名的唯一约束而导致第二本书失败.

我是否期望/想要发生,是否创建了第二本书,并且将第二本书与原始作者记录相关联,而不是尝试创建第二本/重复作者.

@Entity(name = 'book')
class Book {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    long id
    ...
    @ManyToMany(fetch = FetchType.EAGER, cascade = [CascadeType.ALL])
    @JoinTable(name = 'books_authors', joinColumns = @JoinColumn(name = 'book_id'),
        inverseJoinColumns = @JoinColumn(name = 'author_id'))
    @RestResource(exported = false)
    Set<Author> authors
}

@Entity(name = 'author')
@ToString
class Author {

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    long id

    @Column(nullable = false, unique = true)
    String fullName

    @ManyToMany(mappedBy = "authors")
    Set<Book> books
}

@RepositoryRestResource(collectionResourceRel = "authors", path = "authors")
interface AuthorRepository extends PagingAndSortingRepository<Author, Long> …

嗨我正在使用spring数据休息,并且当我使用PagingAndSortingRepository时,我得到一个奇怪的问题,我得到的响应有一个_self链接,但是它也提供了同一个实体的重复链接hf:foo作为以下响应中的evindent.

dupicate links "self":{"href":" http:// localhost:8080/foos/8445 "}和"hf:foo":{"href":" http:// localhost:8080/foos/8445 "

  curl http://localhost:8080/foos?page=0&size=1

        {
      "_links" : {
    "first" : {
      "href" : "http://localhost:8080/foos?page=0&size=1"
    },
    "prev" : {
      "href" : "http://localhost:8080/foos?page=0&size=1"
    },
    "self" : {
      "href" : "http://localhost:8080/foos"
    },
    "next" : {
      "href" : "http://localhost:8080/foos?page=2&size=1"
    },
    "last" : {
      "href" : "http://localhost:8080/foos?page=81&size=1"
    }
  },
  "_embedded" : {
    "hf:foos" : [ {
      "name" : "comsi",
      "_links" : {
        "self" : {
          "href" : "http://localhost:8080/foos/8445"
        },
        "hf:foo" : {
          "href" : "http://localhost:8080/foos/8445"
        } ] …

我在使用 EntityManager Here my User 实体从数据库中获取数据时遇到问题

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@JsonProperty
private Integer id;
@Column(name = "username", length = 20, nullable = false)
@JsonProperty
private String username;
@Column(name = "password", nullable = false, unique = true)
@JsonProperty
private String password;
@Column(name = "enabled", nullable = false)
@JsonProperty
private boolean enabled;
@Column(name = "email", nullable = false, unique = true)
@JsonProperty
private String email;
@OneToMany(mappedBy = "user", cascade = {CascadeType.ALL}, fetch = FetchType.LAZY)
private Set<UserRole> userRoles;
//getters and setters

我尝试使用用户名搜索用户：

public …

在Spring Data JPA的"入门"示例中,我们创建了一个扩展CrudRepository的接口.但是它只处理一个实体:

import org.springframework.data.repository.CrudRepository;

interface MyEntityRepository extends CrudRepository<MyEntity, Long> {
  // methods...
}

在实际应用程序中,有许多实体(表),我们需要为它们执行CRUD操作.使用具有多个(相关或不相关)实体的Spring Data JPA存储库的正确方法是什么？

我是否必须为每个实体创建接口并逐个自动装配它们(这听起来非常疯狂)？

我不是很喜欢Hibernate和Spring Data JPA,我有以下疑问.

我有这个方法签名正确执行查询:

@Repository
public interface AccomodationMediaDAO extends JpaRepository<AccomodationMedia, Long> {

    AccomodationMedia findByIdAccomodationAndIsMaster(Long accomodationId, boolean isMaster);

}

它找到(在AccomodationMedia实体类映射的表上)具有名为idAccomodation的字段的单个记录,该字段设置有由accomodationId方法参数表示的Long值,并且字段isMaster由isMaster布尔值重新呈现.

它工作正常,但我的"问题"是这样做我总是显式传递布尔值isMaster参数的值.

此参数必须始终设置为true,所以我尝试以这种方式更改以前的方法签名:

AccomodationMedia findByIdAccomodationAndIsMaster(Long accomodationId, true);

但IntelliJ显示错误:标识符或预期类型.

为什么？我可以设置必须将此参数的值显式设置为true布尔值吗？