Hibernate - 无法从父对象中删除子对象

Question

我有一个映射到应用程序中父对象的子对象列表。现在，当用户从UI中删除任何子条目时，我必须删除子对象和父对象关联，并从数据库中删除子记录。我的代码中的所有内容似乎都很好，但代码既不会删除父子关联，也不会从数据库中删除子记录。以下是我的代码：

服务代码：

List<ServerConfig> existingConfig = serverMasterService.getServerConfigForServer(serverId);
            Set<ServerConfig> temp = new HashSet<ServerConfig>();

            for (ServerConfig sConfig : serverMstr.getServerConfigs()) {
                    for (ServerConfig eConfig : existingConfig){
                        if(sConfig.getAttributeId() == eConfig.getAttributeId()){
                            sConfig.setConfigId(eConfig.getConfigId());
                        }else{
                            temp.add(sConfig);
                        }
                    }
                    sConfig.setServer(serverMstr);
            }
            serverMstr.getServerConfigs().removeAll(temp);
        }
    this.serverMasterService.saveServerMasters(serverMstr);

DAO代码：

public void saveServerMasters(ServerMstr serverMstr) {
        hibernateTemplate.saveOrUpdate(serverMstr);
    }

父级HBM文件：

<set name="serverConfigs" inverse="true" cascade="all" lazy="false">
         <key>
            <column name="serverId" not-null="true"/>
         </key>
         <one-to-many class="com.serverApp.business.model.ServerConfig"/>
   </set> 

儿童HBM文件：

<many-to-one name="server" class="com.serverApp.business.model.ServerMstr" 
    cascade="all" lazy="false" foreign-key="FK_SERVERMSTR" >
        <column name="ServerId" not-null="true"/>
    </many-to-one>

即使我通过以下代码删除所有子记录，子对象也不会被删除。

serverMstr.getServerConfigs().removeAll(serverMstr.getServerConfigs());
this.serverMasterService.saveServerMasters(serverMstr);

修改

父对象类：

package com.serverApp.business.model;

import java.util.Set;

import javax.xml.bind.annotation.XmlRootElement;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;

@XmlRootElement(name = "ServerMaster")
@JsonIgnoreProperties({"environmentMstr"})  
public class ServerMstr      {

@JsonProperty("ID")
private Long id;

@JsonProperty("ServerConfigs")
private Set<ServerConfig> serverConfigs;

public Set<ServerConfig> getServerConfigs() {
    return serverConfigs;
}


public void setServerConfigs(Set<ServerConfig>  serverConfigs) {
    this.serverConfigs = serverConfigs;
}

public Long getId() {
    return id;
}


public void setId(Long id) {
    this.id = id;
}

@JsonProperty("Name")
private String name;

@JsonProperty("Notes")
private String notes;

@JsonProperty("Location")
private String location; 

@JsonProperty("SerialNo")
private String serialNo;

@JsonProperty("ServerFunction")
private String serverFunction; 

@JsonProperty("ServerType")
private String serverType; 

@JsonProperty("PrimAppl")
private String primAppl; 

@JsonProperty("Status")
private String status; 

@JsonProperty("IPAddress")
private String ipAddr; 

public String getLocation() {
    return location;
}


public void setLocation(String location) {
    this.location = location;
}


public String getSerialNo() {
    return serialNo;
}


public void setSerialNo(String serialNo) {
    this.serialNo = serialNo;
}


public String getServerFunction() {
    return serverFunction;
}


public void setServerFunction(String serverFunction) {
    this.serverFunction = serverFunction;
}


public String getServerType() {
    return serverType;
}


public void setServerType(String serverType) {
    this.serverType = serverType;
}


public String getPrimAppl() {
    return primAppl;
}


public void setPrimAppl(String primAppl) {
    this.primAppl = primAppl;
}


public String getStatus() {
    return status;
}


public void setStatus(String status) {
    this.status = status;
}


public String getIpAddr() {
    return ipAddr;
}


public void setIpAddr(String ipAddr) {
    this.ipAddr = ipAddr;
}


public String getNotes() {
    return notes;
}

public void setNotes(String notes) {
    this.notes = notes;
}

public ServerMstr(){
}

public ServerMstr(   String name, String notes ){
    this.name = name;
    this.notes=notes;
} 

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}


@Override
public String toString() {
    return "ServerMstr [id=" + id + ", serverConfigs=" + serverConfigs
            + ", name=" + name + ", notes=" + notes + ", location="
            + location + ", serialNo=" + serialNo + ", serverFunction="
            + serverFunction + ", serverType=" + serverType + ", primAppl="
            + primAppl + ", status=" + status + ", ipAddr=" + ipAddr + "]";
}

}

子对象：

package com.serverApp.business.model;


import javax.xml.bind.annotation.XmlRootElement;

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;


@XmlRootElement(name = "ServerConfig")
@JsonIgnoreProperties({"configId", "server"})
public class ServerConfig    {

@JsonIgnore
private ServerMstr server; 

private Long configId; 



@Override
public String toString() {
    return "ServerConfig [server=" + server.getName() + ", configId=" + configId
            + ", attributeId=" + attributeId + ", value=" + value
            + ", serverId=" + serverId + "]";
}

@JsonProperty("AttributeId")
private Long attributeId;

@JsonProperty("Value")
private String value;

@JsonProperty("ServerId")
private Long serverId; 


public Long getConfigId() {
    return configId;
}

public void setConfigId(Long configId) {
    this.configId = configId;
}

public Long getServerId() {
    return serverId;
}

public void setServerId(Long serverId) {
    this.serverId = serverId;
}

public Long getAttributeId() {
    return attributeId;
}

public void setAttributeId(Long attributeId) {
    this.attributeId = attributeId;
}


public String getValue() {
    return value;
}

public void setValue(String value) {
    this.value = value;
}

public ServerConfig() {
}

public ServerConfig( Long serverId, Long attributeId, String value )
{
    this.serverId = serverId;
    this.attributeId = attributeId;
    this.value=value;
 }

public void setServer(ServerMstr server) {
    this.server = server;
}

public ServerMstr getServer() {
    return server;
}

}

DAO代码：

package com.serverApp.business.dao;

import java.util.List;

import org.apache.log4j.Logger;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Restrictions;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import com.serverApp.business.model.ServerConfig;
import com.serverApp.business.model.ServerMstr;

@Repository ("serverMstrDao")
public class ServerMstrDaoImpl extends AbstractDAOImpl implements  ServerMstrDao{

private static final Logger logger = Logger.getLogger(ServerMstrDaoImpl.class);

/*
 * This Method will be used to retrieve the list of ServerMstr Class Details from the DB
 * (non-Javadoc)
 * @see com.serverApp.business.dao.ServerMstrDao#listServerMstrs()
 */
@Override
@SuppressWarnings({"unchecked" })
public List<ServerMstr> listServerMstrs() {
    if (logger.isDebugEnabled()) {
        logger.debug("Inside listServerMstrs() ");
    }
    return (List<ServerMstr>)hibernateTemplate.find("from ServerMstr");
}

/*
 * This Method will be used to save new server to database
 *  (non-Javadoc)
 * @see com.serverApp.business.dao.ServerMstrDao#saveServerMasters(com.serverApp.business.model.ServerMstr)
 */
@Override
 @Transactional  
    public void saveServerMasters(ServerMstr serverMstr) {
    if (logger.isDebugEnabled()) {
        logger.debug("Inside saveServerMasters() ");
    }

        System.out.println("DAO Print: "+serverMstr.toString());
        hibernateTemplate.saveOrUpdate(serverMstr);
    }

/*
 * This Method will be used to retrieve the ServerMstr Class Details from the DB for the given name
 * (non-Javadoc)
 * @see com.serverApp.business.dao.ServerMstrDao#getServerByName()
 */
@SuppressWarnings("unchecked")
@Override
public ServerMstr getServerByName(String name) {
    if (logger.isDebugEnabled()) {
        logger.debug("fetching server from database with name : " + name );
    }
    DetachedCriteria criteria = DetachedCriteria.forClass(ServerMstr.class);
    criteria.add(Restrictions.eq("name", name));
    List<ServerMstr> serverMstr = hibernateTemplate.findByCriteria(criteria); 
    if(serverMstr.size() != 1)
    {
        logger.error("Multiple or 0 row returned for selection Server name: " + name );
        return null;
    }
    return (ServerMstr)serverMstr.get(0);
}

/*
 * This Method will be used to retrieve the ServerConfig Class List from the DB for the given server id
 * (non-Javadoc)
 * @see com.serverApp.business.dao.ServerMstrDao#getServerConfigForServer()
 */
@SuppressWarnings("unchecked")
@Override
public List<ServerConfig> getServerConfigForServer(Long serverId) {
    if (logger.isDebugEnabled()) {
        logger.debug("fetching ServerConfig list from database for server with id : " + serverId );
    }

    return hibernateTemplate.find("from ServerConfig where serverId = ?",serverId);
}
}

非常感谢任何帮助/建议

Answer 1

在这种情况下，您需要删除孤儿。级联类型all确实会级联所有操作，但是对于要发生的子对象的删除操作，您需要对父级执行删除操作，这不是您在示例中要执行的操作。像这样更改您的映射：

<set name="serverConfigs" inverse="true" cascade="all-delete-orphan" lazy="false">
    <key>
        <column name="serverId" not-null="true"/>
    </key>
    <one-to-many class="com.serverApp.business.model.ServerConfig"/>
</set> 

Answer 2

您需要在POJO对象中覆盖equals和haschode方法。如果你不这样做，Hibernate将无法比较子对象，它们将继续作为孤儿继续存在于数据库中。

另一个选项可以是查找父项的所有子项，然后单独删除它们，如下面的代码所示。 ：

Iterator<Child> i = form.getDeleteItems().iterator();
while(i.hasNext()){
Child child = i.next();
for (Iterator<Child> it = parent.getChildren().iterator();) {
     if (child.getId().equals(it.next().getId()) {
         it.remove(); 
     }
   }
}