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我知道这个问题经常出现在这里,但解决方案要么我还不理解,要么没有帮助。我有一个“牧师”实体,基本上是一名老师。然后我们有参与者,或者说学生。在参与者中,我想存储分配给他们的牧师的电子邮件地址。他们在此字段中只能有一个电子邮件地址。这是有问题的代码:
我收到此错误消息:
HTTP Status 500 - Request processing failed; nested exception is org.hibernate.MappingException: Repeated column in mapping for entity: com.grandcircus.spring.models.ChaplainsEntity column: email (should be mapped with insert="false" update="false")
这是有问题的代码:
牧师实体.JAVA
package com.grandcircus.spring.models;
import javax.persistence.*;
import java.util.Collection;
/**
* Class description
*
* @author Sarah Guarino
* @version 1.0
*/
@Entity
@Table(name = "chaplains", schema = "firststepfreedom", catalog = "")
public class ChaplainsEntity {
private String id;
private String firstname;
private String lastname;
private String email;
private String phonenumber;
private String addresslineone;
private String addresslinetwo;
private String addresscountry;
private String addressstate;
private String addresscounty;
private String addresscity;
private String addresszip;
private int deprecated;
private int activated;
private String passcode;
private Collection<ClassesEntity> classesById;
private ParticipantsEntity participantsByEmail;
@Id
@Column(name = "id", nullable = false, length = 10)
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
@Basic
@Column(name = "firstname", nullable = false, length = -1)
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
@Basic
@Column(name = "lastname", nullable = false, length = -1)
public String getLastname() {
return lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
@Basic
@Column(name = "email", nullable = false, length = 60)
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Basic
@Column(name = "phonenumber", nullable = false, length = 25)
public String getPhonenumber() {
return phonenumber;
}
public void setPhonenumber(String phonenumber) {
this.phonenumber = phonenumber;
}
@Basic
@Column(name = "addresslineone", nullable = false, length = -1)
public String getAddresslineone() {
return addresslineone;
}
public void setAddresslineone(String addresslineone) {
this.addresslineone = addresslineone;
}
@Basic
@Column(name = "addresslinetwo", nullable = false, length = -1)
public String getAddresslinetwo() {
return addresslinetwo;
}
public void setAddresslinetwo(String addresslinetwo) {
this.addresslinetwo = addresslinetwo;
}
@Basic
@Column(name = "addresscountry", nullable = false, length = -1)
public String getAddresscountry() {
return addresscountry;
}
public void setAddresscountry(String addresscountry) {
this.addresscountry = addresscountry;
}
@Basic
@Column(name = "addressstate", nullable = false, length = 2)
public String getAddressstate() {
return addressstate;
}
public void setAddressstate(String addressstate) {
this.addressstate = addressstate;
}
@Basic
@Column(name = "addresscounty", nullable = false, length = -1)
public String getAddresscounty() {
return addresscounty;
}
public void setAddresscounty(String addresscounty) {
this.addresscounty = addresscounty;
}
@Basic
@Column(name = "addresscity", nullable = false, length = -1)
public String getAddresscity() {
return addresscity;
}
public void setAddresscity(String addresscity) {
this.addresscity = addresscity;
}
@Basic
@Column(name = "addresszip", nullable = false, length = 10)
public String getAddresszip() {
return addresszip;
}
public void setAddresszip(String addresszip) {
this.addresszip = addresszip;
}
@Basic
@Column(name = "deprecated", nullable = false)
public int getDeprecated() {
return deprecated;
}
public void setDeprecated(int deprecated) {
this.deprecated = deprecated;
}
@Basic
@Column(name = "activated", nullable = false)
public int getActivated() {
return activated;
}
public void setActivated(int activated) {
this.activated = activated;
}
@Basic
@Column(name = "passcode", nullable = false, length = -1)
public String getPasscode() {
return passcode;
}
public void setPasscode(String passcode) {
this.passcode = passcode;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ChaplainsEntity that = (ChaplainsEntity) o;
if (phonenumber != that.phonenumber) return false;
if (deprecated != that.deprecated) return false;
if (activated != that.activated) return false;
if (id != null ? !id.equals(that.id) : that.id != null) return false;
if (firstname != null ? !firstname.equals(that.firstname) : that.firstname != null) return false;
if (lastname != null ? !lastname.equals(that.lastname) : that.lastname != null) return false;
if (email != null ? !email.equals(that.email) : that.email != null) return false;
if (addresslineone != null ? !addresslineone.equals(that.addresslineone) : that.addresslineone != null)
return false;
if (addresslinetwo != null ? !addresslinetwo.equals(that.addresslinetwo) : that.addresslinetwo != null)
return false;
if (addresscountry != null ? !addresscountry.equals(that.addresscountry) : that.addresscountry != null)
return false;
if (addressstate != null ? !addressstate.equals(that.addressstate) : that.addressstate != null) return false;
if (addresscounty != null ? !addresscounty.equals(that.addresscounty) : that.addresscounty != null)
return false;
if (addresscity != null ? !addresscity.equals(that.addresscity) : that.addresscity != null) return false;
if (addresszip != null ? !addresszip.equals(that.addresszip) : that.addresszip != null) return false;
if (passcode != null ? !passcode.equals(that.passcode) : that.passcode != null) return false;
return true;
}
@Override
public int hashCode() {
int result = id != null ? id.hashCode() : 0;
result = 31 * result + (firstname != null ? firstname.hashCode() : 0);
result = 31 * result + (lastname != null ? lastname.hashCode() : 0);
result = 31 * result + (email != null ? email.hashCode() : 0);
result = 31 * result + (phonenumber != null ? addresslineone.hashCode() : 0);
result = 31 * result + (addresslineone != null ? addresslineone.hashCode() : 0);
result = 31 * result + (addresslinetwo != null ? addresslinetwo.hashCode() : 0);
result = 31 * result + (addresscountry != null ? addresscountry.hashCode() : 0);
result = 31 * result + (addressstate != null ? addressstate.hashCode() : 0);
result = 31 * result + (addresscounty != null ? addresscounty.hashCode() : 0);
result = 31 * result + (addresscity != null ? addresscity.hashCode() : 0);
result = 31 * result + (addresszip != null ? addresszip.hashCode() : 0);
result = 31 * result + deprecated;
result = 31 * result + activated;
result = 31 * result + (passcode != null ? passcode.hashCode() : 0);
return result;
}
@OneToMany(mappedBy = "chaplainsByChaplainsid")
public Collection<ClassesEntity> getClassesById() {
return classesById;
}
public void setClassesById(Collection<ClassesEntity> classesById) {
this.classesById = classesById;
}
@ManyToOne
@JoinColumn(name = "email", referencedColumnName = "chaplainemail", nullable = false)
public ParticipantsEntity getParticipantsByEmail() {
return participantsByEmail;
}
public void setParticipantsByEmail(ParticipantsEntity participantsByEmail) {
this.participantsByEmail = participantsByEmail;
}
}
参与实体.JAVA
package com.grandcircus.spring.models;
import javax.persistence.*;
import java.sql.Date;
import java.util.Collection;
/**
* Class description
*
* @author Sarah Guarino
* @version 1.0
*/
@Entity
@Table(name = "participants", schema = "firststepfreedom", catalog = "")
public class ParticipantsEntity {
private String firstname;
private String lastname;
private String email;
private String phonenumber;
private String casenum;
private int weekscompleted;
private int weeksneeded;
private String offensetype;
private String addresscountry;
private String addressstate;
private String addresscounty;
private String addresscity;
private String addresszip;
private int deprecated;
private int id;
private String chaplainemail;
private String addresslinetwo;
private String passcode;
private String addresslineone;
private int activated;
private Date sentencestart;
private Date sentenceend;
private Collection<AppointmentsEntity> appointmentsById;
private Collection<ChaplainsEntity> participantsByEmail;
@Basic
@Column(name = "firstname", nullable = false, length = -1)
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
@Basic
@Column(name = "lastname", nullable = false, length = -1)
public String getLastname() {
return lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
@Basic
@Column(name = "email", nullable = false, length = 60)
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
@Basic
@Column(name = "phonenumber", nullable = false, length = 25)
public String getPhonenumber() {
return phonenumber;
}
public void setPhonenumber(String phonenumber) {
this.phonenumber = phonenumber;
}
@Basic
@Column(name = "casenum", nullable = false, length = 45)
public String getCasenum() {
return casenum;
}
public void setCasenum(String casenum) {
this.casenum = casenum;
}
@Basic
@Column(name = "weekscompleted", nullable = false)
public int getWeekscompleted() {
return weekscompleted;
}
public void setWeekscompleted(int weekscompleted) {
this.weekscompleted = weekscompleted;
}
@Basic
@Column(name = "weeksneeded", nullable = false)
public int getWeeksneeded() {
return weeksneeded;
}
public void setWeeksneeded(int weeksneeded) {
this.weeksneeded = weeksneeded;
}
@Basic
@Column(name = "offensetype", nullable = true, length = -1)
public String getOffensetype() {
return offensetype;
}
public void setOffensetype(String offensetype) {
this.offensetype = offensetype;
}
@Basic
@Column(name = "addresscountry", nullable = false, length = -1)
public String getAddresscountry() {
return addresscountry;
}
public void setAddresscountry(String addresscountry) {
this.addresscountry = addresscountry;
}
@Basic
@Column(name = "addressstate", nullable = false, length = 2)
public String getAddressstate() {
return addressstate;
}
public void setAddressstate(String addressstate) {
this.addressstate = addressstate;
}
@Basic
@Column(name = "addresscounty", nullable = false, length = -1)
public String getAddresscounty() {
return addresscounty;
}
public void setAddresscounty(String addresscounty) {
this.addresscounty = addresscounty;
}
@Basic
@Column(name = "addresscity", nullable = false, length = -1)
public String getAddresscity() {
return addresscity;
}
public void setAddresscity(String addresscity) {
this.addresscity = addresscity;
}
@Basic
@Column(name = "addresszip", nullable = false, length = 10)
public String getAddresszip() {
return addresszip;
}
public void setAddresszip(String addresszip) {
this.addresszip = addresszip;
}
@Basic
@Column(name = "deprecated", nullable = false)
public int getDeprecated() {
return deprecated;
}
public void setDeprecated(int deprecated) {
this.deprecated = deprecated;
}
@Id
@Column(name = "id", nullable = false)
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
@Basic
@Column(name = "chaplainemail", nullable = true, length = 60)
public String getChaplainemail() {
return chaplainemail;
}
public void setChaplainemail(String chaplainemail) {
this.chaplainemail = chaplainemail;
}
@Basic
@Column(name = "addresslinetwo", nullable = true, length = -1)
public String getAddresslinetwo() {
return addresslinetwo;
}
public void setAddresslinetwo(String addresslinetwo) {
this.addresslinetwo = addresslinetwo;
}
@Basic
@Column(name = "passcode", nullable = false, length = -1)
public String getPasscode() {
return passcode;
}
public void setPasscode(String passcode) {
this.passcode = passcode;
}
@Basic
@Column(name = "addresslineone", nullable = false, length = -1)
public String getAddresslineone() {
return addresslineone;
}
public void setAddresslineone(String addresslineone) {
this.addresslineone = addresslineone;
}
@Basic
@Column(name = "activated", nullable = false)
public int getActivated() {
return activated;
}
public void setActivated(int activated) {
this.activated = activated;
}
@Basic
@Column(name = "sentencestart", nullable = false)
public Date getSentencestart() {
return sentencestart;
}
public void setSentencestart(Date sentencestart) {
this.sentencestart = sentencestart;
}
@Basic
@Column(name = "sentenceend", nullable = false)
public Date getSentenceend() {
return sentenceend;
}
public void setSentenceend(Date sentenceend) {
this.sentenceend = sentenceend;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ParticipantsEntity that = (ParticipantsEntity) o;
if (weekscompleted != that.weekscompleted) return false;
if (weeksneeded != that.weeksneeded) return false;
if (deprecated != that.deprecated) return false;
if (id != that.id) return false;
if (activated != that.activated) return false;
if (firstname != null ? !firstname.equals(that.firstname) : that.firstname != null) return false;
if (lastname != null ? !lastname.equals(that.lastname) : that.lastname != null) return false;
if (email != null ? !email.equals(that.email) : that.email != null) return false;
if (phonenumber != null ? !phonenumber.equals(that.phonenumber) : that.phonenumber != null) return false;
if (casenum != null ? !casenum.equals(that.casenum) : that.casenum != null) return false;
if (offensetype != null ? !offensetype.equals(that.offensetype) : that.offensetype != null) return false;
if (addresscountry != null ? !addresscountry.equals(that.addresscountry) : that.addresscountry != null)
return false;
if (addressstate != null ? !addressstate.equals(that.addressstate) : that.addressstate != null) return false;
if (addresscounty != null ? !addresscounty.equals(that.addresscounty) : that.addresscounty != null)
return false;
if (addresscity != null ? !addresscity.equals(that.addresscity) : that.addresscity != null) return false;
if (addresszip != null ? !addresszip.equals(that.addresszip) : that.addresszip != null) return false;
if (chaplainemail != null ? !chaplainemail.equals(that.chaplainemail) : that.chaplainemail != null)
return false;
if (addresslinetwo != null ? !addresslinetwo.equals(that.addresslinetwo) : that.addresslinetwo != null)
return false;
if (passcode != null ? !passcode.equals(that.passcode) : that.passcode != null) return false;
if (addresslineone != null ? !addresslineone.equals(that.addresslineone) : that.addresslineone != null)
return false;
if (sentencestart != null ? !sentencestart.equals(that.sentencestart) : that.sentencestart != null)
return false;
if (sentenceend != null ? !sentenceend.equals(that.sentenceend) : that.sentenceend != null) return false;
return true;
}
@Override
public int hashCode() {
int result = firstname != null ? firstname.hashCode() : 0;
result = 31 * result + (lastname != null ? lastname.hashCode() : 0);
result = 31 * result + (email != null ? email.hashCode() : 0);
result = 31 * result + (phonenumber != null ? phonenumber.hashCode() : 0);
result = 31 * result + (casenum != null ? casenum.hashCode() : 0);
result = 31 * result + weekscompleted;
result = 31 * result + weeksneeded;
result = 31 * result + (offensetype != null ? offensetype.hashCode() : 0);
result = 31 * result + (addresscountry != null ? addresscountry.hashCode() : 0);
result = 31 * result + (addressstate != null ? addressstate.hashCode() : 0);
result = 31 * result + (addresscounty != null ? addresscounty.hashCode() : 0);
result = 31 * result + (addresscity != null ? addresscity.hashCode() : 0);
result = 31 * result + (addresszip != null ? addresszip.hashCode() : 0);
result = 31 * result + deprecated;
result = 31 * result + id;
result = 31 * result + (chaplainemail != null ? chaplainemail.hashCode() : 0);
result = 31 * result + (addresslinetwo != null ? addresslinetwo.hashCode() : 0);
result = 31 * result + (passcode != null ? passcode.hashCode() : 0);
result = 31 * result + (addresslineone != null ? addresslineone.hashCode() : 0);
result = 31 * result + activated;
result = 31 * result + (sentencestart != null ? sentencestart.hashCode() : 0);
result = 31 * result + (sentenceend != null ? sentenceend.hashCode() : 0);
return result;
}
@OneToMany(mappedBy = "participantsByParticipantid")
public Collection<AppointmentsEntity> getAppointmentsById() {
return appointmentsById;
}
public void setAppointmentsById(Collection<AppointmentsEntity> appointmentsById) {
this.appointmentsById = appointmentsById;
}
@OneToMany(mappedBy = "participantsByEmail")
public Collection<ChaplainsEntity> getParticipantsByEmail() {
return participantsByEmail;
}
public void setParticipantsByEmail(Collection<ChaplainsEntity> participantsByEmail) {
this.participantsByEmail = participantsByEmail;
}
}
CHAPLAINENTITY hibernate xm
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.grandcircus.spring.models.ChaplainsEntity" table="chaplains" schema="firststepfreedom">
<id name="id">
<column name="id" sql-type="varchar(10)" length="10"/>
</id>
<property name="firstname">
<column name="firstname" sql-type="tinytext"/>
</property>
<property name="lastname">
<column name="lastname" sql-type="tinytext"/>
</property>
<property name="email">
<column name="email" sql-type="varchar(60)" length="60"/>
</property>
<property name="phonenumber">
<column name="phonenumber" sql-type="varchar(25)" length="25"/>
</property>
<property name="addresslineone">
<column name="addresslineone" sql-type="tinytext"/>
</property>
<property name="addresslinetwo">
<column name="addresslinetwo" sql-type="tinytext"/>
</property>
<property name="addresscountry">
<column name="addresscountry" sql-type="tinytext"/>
</property>
<property name="addressstate">
<column name="addressstate" sql-type="varchar(2)" length="2"/>
</property>
<property name="addresscounty">
<column name="addresscounty" sql-type="tinytext"/>
</property>
<property name="addresscity">
<column name="addresscity" sql-type="tinytext"/>
</property>
<property name="addresszip">
<column name="addresszip" sql-type="varchar(10)" length="10"/>
</property>
<property name="deprecated">
<column name="deprecated" sql-type="int(1)"/>
</property>
<property name="activated">
<column name="activated" sql-type="int(1)"/>
</property>
<property name="passcode">
<column name="passcode" sql-type="tinytext"/>
</property>
<many-to-one name="participantsByEmail" class="com.grandcircus.spring.models.ParticipantsEntity">
<column name="email"/>
</many-to-one>
<set name="classesById" inverse="true">
<key>
<column name="chaplainsid"/>
</key>
<one-to-many not-found="ignore" class="com.grandcircus.spring.models.ClassesEntity"/>
</set>
</class>
</hibernate-mapping>
PARTICIPANTENTITY hibernate xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.grandcircus.spring.models.ParticipantsEntity" table="participants" schema="firststepfreedom">
<id name="id">
<column name="id" sql-type="int(11) unsigned zerofill"/>
</id>
<property name="firstname">
<column name="firstname" sql-type="tinytext"/>
</property>
<property name="lastname">
<column name="lastname" sql-type="tinytext"/>
</property>
<property name="email">
<column name="email" sql-type="varchar(60)" length="60"/>
</property>
<property name="phonenumber">
<column name="phonenumber" sql-type="varchar(25)" length="25"/>
</property>
<property name="casenum">
<column name="casenum" sql-type="varchar(45)" length="45"/>
</property>
<property name="weekscompleted">
<column name="weekscompleted" sql-type="int(3)"/>
</property>
<property name="weeksneeded">
<column name="weeksneeded" sql-type="int(3)"/>
</property>
<property name="offensetype">
<column name="offensetype" sql-type="tinytext" not-null="true"/>
</property>
<property name="addresscountry">
<column name="addresscountry" sql-type="tinytext"/>
</property>
<property name="addressstate">
<column name="addressstate" sql-type="varchar(2)" length="2"/>
</property>
<property name="addresscounty">
<column name="addresscounty" sql-type="tinytext"/>
</property>
<property name="addresscity">
<column name="addresscity" sql-type="tinytext"/>
</property>
<property name="addresszip">
<column name="addresszip" sql-type="varchar(10)" length="10"/>
</property>
<property name="deprecated">
<column name="deprecated" sql-type="int(1)"/>
</property>
<property name="chaplainemail">
<column name="chaplainemail" sql-type="varchar(60)" length="60" not-null="true"/>
</property>
<property name="addresslinetwo">
<column name="addresslinetwo" sql-type="tinytext" not-null="true"/>
</property>
<property name="passcode">
<column name="passcode" sql-type="tinytext"/>
</property>
<property name="addresslineone">
<column name="addresslineone" sql-type="tinytext"/>
</property>
<property name="activated">
<column name="activated" sql-type="int(1)"/>
</property>
<property name="sentencestart">
<column name="sentencestart" sql-type="date"/>
</property>
<property name="sentenceend">
<column name="sentenceend" sql-type="date"/>
</property>
<set name="appointmentsById" inverse="true">
<key>
<column name="participantid"/>
</key>
<one-to-many not-found="ignore" class="com.grandcircus.spring.models.AppointmentsEntity"/>
</set>
<set name="participantsByEmail" inverse="true">
<key>
<column name="email"/>
</key>
<one-to-many not-found="ignore" class="com.grandcircus.spring.models.ChaplainsEntity"/>
</set>
</class>
</hibernate-mapping>
我做错了什么?
最佳答案
您的问题是在 ChaplainsEntity
类中,您已将 email
列映射到两个不同的字段 - email
和 参与者通过电子邮件
。
这是一个错误,因为如果您的 ChaplainsEntity
对象在这两个字段中具有不同的 email
值,Hibernate 将不知道在该对象中保存哪一个电子邮件
列。唯一可以接受的方法是,从 Hibernate 的角度来看,该列是只读的 - 也就是说,您永远不会要求 Hibernate 插入或更新该值。
关于java - (应使用 insert ="false"update ="false"进行映射),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44742585/
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如果我将使用 Java 5 代码的应用程序编译成字节码,生成的 .class 文件是否能够在 Java 1.4 下运行? 如果后者可以工作并且我正在尝试在我的 Java 1.4 应用程序中使用 Jav
有关于why Java doesn't support unsigned types的问题以及一些关于处理无符号类型的问题。我做了一些搜索,似乎 Scala 也不支持无符号数据类型。限制是Java和S
我只是想知道在一个 java 版本中生成的字节码是否可以在其他 java 版本上运行 最佳答案 通常,字节码无需修改即可在 较新 版本的 Java 上运行。它不会在旧版本上运行,除非您使用特殊参数 (
我有一个关于在命令提示符下执行 java 程序的基本问题。 在某些机器上我们需要指定 -cp 。 (类路径)同时执行java程序 (test为java文件名与.class文件存在于同一目录下) jav
我已经阅读 StackOverflow 有一段时间了,现在我才鼓起勇气提出问题。我今年 20 岁,目前在我的家乡(罗马尼亚克卢日-纳波卡)就读 IT 大学。足以介绍:D。 基本上,我有一家提供簿记应用
我有 public JSONObject parseXML(String xml) { JSONObject jsonObject = XML.toJSONObject(xml); r
我已经在 Java 中实现了带有动态类型的简单解释语言。不幸的是我遇到了以下问题。测试时如下代码: def main() { def ks = Map[[1, 2]].keySet()
一直提示输入 1 到 10 的数字 - 结果应将 st、rd、th 和 nd 添加到数字中。编写一个程序,提示用户输入 1 到 10 之间的任意整数,然后以序数形式显示该整数并附加后缀。 public
我有这个 DownloadFile.java 并按预期下载该文件: import java.io.*; import java.net.URL; public class DownloadFile {
我想在 GUI 上添加延迟。我放置了 2 个 for 循环,然后重新绘制了一个标签,但这 2 个 for 循环一个接一个地执行,并且标签被重新绘制到最后一个。 我能做什么? for(int i=0;
我正在对对象 Student 的列表项进行一些测试,但是我更喜欢在 java 类对象中创建硬编码列表,然后从那里提取数据,而不是连接到数据库并在结果集中选择记录。然而,自从我这样做以来已经很长时间了,
我知道对象创建分为三个部分: 声明 实例化 初始化 classA{} classB extends classA{} classA obj = new classB(1,1); 实例化 它必须使用
我有兴趣使用 GPRS 构建车辆跟踪系统。但是,我有一些问题要问以前做过此操作的人: GPRS 是最好的技术吗?人们意识到任何问题吗? 我计划使用 Java/Java EE - 有更好的技术吗? 如果
我可以通过递归方法反转数组,例如:数组={1,2,3,4,5} 数组结果={5,4,3,2,1}但我的结果是相同的数组,我不知道为什么,请帮助我。 public class Recursion { p
有这样的标准方式吗? 包括 Java源代码-测试代码- Ant 或 Maven联合单元持续集成(可能是巡航控制)ClearCase 版本控制工具部署到应用服务器 最后我希望有一个自动构建和集成环境。
我什至不知道这是否可能,我非常怀疑它是否可能,但如果可以,您能告诉我怎么做吗?我只是想知道如何从打印机打印一些文本。 有什么想法吗? 最佳答案 这里有更简单的事情。 import javax.swin
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