java 克隆

分手后的思念是犯贱 2022-05-11 11:44 127阅读 0赞

Java 克隆分为浅克隆和深克隆

浅克隆：

将原型的所有属性的值复制到新对象，新对象基本数据类型的字段值的改变不会影响到被复制对象，而引用类型复制的是指向堆的引用地址，所以新对象和被复制对象的引用类型指的是同一个地址，任意一个改变，都会受印象

public class InfomationType implements Cloneable{
        @SerializedName("TYPEID")
        private String typeId;//类型ID
        @SerializedName("TYPENAME")
        public String typeName;//类型名称
        @SerializedName("TIMES")
        private String times;//显示时间段
        @SerializedName("PARENTID")
        private String parentId;//父ID
    
       public XgMessageInfo xgMessageInfo;
    
        public XgMessageInfo getXgMessageInfo() {
            return xgMessageInfo;
        }
    
        public void setXgMessageInfo(XgMessageInfo xgMessageInfo) {
            this.xgMessageInfo = xgMessageInfo;
        }
    
        public String getTypeId() {
            return typeId;
        }
    
        public void setTypeId(String typeId) {
            this.typeId = typeId;
        }
    
        public String getTypeName() {
            return typeName;
        }
    
        public void setTypeName(String typeName) {
            this.typeName = typeName;
        }
    
        public String getTimes() {
            return times;
        }
    
        public void setTimes(String times) {
            this.times = times;
        }
    
        public String getParentId() {
            return parentId;
        }
    
        public void setParentId(String parentId) {
            this.parentId = parentId;
        }
    
    
    
        @Override
        public Object clone() throws CloneNotSupportedException {
               InfomationType  infomationType=null;
        try{
            infomationType=(InfomationType)super.clone();
        //    infomationType.xgMessageInfo=(XgMessageInfo)xgMessageInfo.clone();
            return infomationType;
        }catch (Exception e){
    
        }
        return null;
    }

}
    }

public class XgMessageInfo implements Serializable {
        private String id;
        private String createTime;
        private String createUser;
        private String createUserName;
        public String infoTitle;
        private String type;
        private String tenantId;
    
    
        public String getId() {
            return id;
        }
    
        public void setId(String id) {
            this.id = id;
        }
    
        public String getCreateTime() {
            return createTime;
        }
    
        public void setCreateTime(String createTime) {
            this.createTime = createTime;
        }
    
        public String getCreateUser() {
            return createUser;
        }
    
        public void setCreateUser(String createUser) {
            this.createUser = createUser;
        }
    
        public String getCreateUserName() {
            return createUserName;
        }
    
        public void setCreateUserName(String createUserName) {
            this.createUserName = createUserName;
        }
    
        public String getInfoTitle() {
            return infoTitle;
        }
    
        public void setInfoTitle(String infoTitle) {
            this.infoTitle = infoTitle;
        }
    
        public String getType() {
            return type;
        }
    
        public void setType(String type) {
            this.type = type;
        }
    
        public String getTenantId() {
            return tenantId;
        }
    
        public void setTenantId(String tenantId) {
            this.tenantId = tenantId;
        }
    }

InfomationType infomationiType  =new InfomationType();
    XgMessageInfo xgMessageInfo=new XgMessageInfo();
    infomationiType.setXgMessageInfo(xgMessageInfo);
    infomationiType.setTypeName("留言信息");
    try {
        InfomationType infomationiTypeClone=(InfomationType)infomationiType.clone();
        Log.d("infoTypeClone",infomationiType.toString());
        Log.d("infoTypeClone","clone="+infomationiTypeClone.toString());
        Log.d("infoTypeClone",infomationiType.typeName.toString());
        Log.d("infoTypeClone","clone="+infomationiTypeClone.typeName.toString());
        Log.d("infoTypeClone",infomationiType.xgMessageInfo.toString());
        Log.d("infoTypeClone","clone="+infomationiTypeClone.xgMessageInfo.toString());
        结果：
         **********.InfomationType@41b17010
         **********.InfomationType@41b17298
         留言信息
         clone=留言信息
         **********.XgMessageInfo@41b17230
         **********.XgMessageInfo@41b17230
    
    
     
        infomationiTypeClone.setTypeName("资讯信息");
        infomationiTypeClone.getXgMessageInfo().setInfoTitle("某某同学....你有一条留言信息");
        Log.d("infoTypeClone",infomationiType.typeName.toString());
        Log.d("infoTypeClone","clone="+infomationiTypeClone.typeName.toString());
        Log.d("infoTypeClone",infomationiType.getXgMessageInfo().getInfoTitle());
        Log.d("infoTypeClone","clone="+infomationiTypeClone.getXgMessageInfo().getInfoTitle());
        结果：
         留言信息
         clone=资讯信息
        某某同学....你有一条留言信息
        clone=某某同学....你有一条留言信息
    } catch (CloneNotSupportedException e) {
        e.printStackTrace();
    }

深克隆：

将原型的所有属性的值复制到新对象，新对象基本数据类型的字段值的改变不会影响到被复制对象，引用类型复制的不是指向堆的引用地址，而是引用的对象，所以原型和深克隆的对象的引用类型指向的是堆上不同的对象。所以克隆对象的引用类型的改变不会影响到与原型的引用类型。

操作：将InfomationType的克隆方法里添加 infomationType.xgMessageInfo=(XgMessageInfo)xgMessageInfo.clone();这句代码

@Override
        public Object clone() throws CloneNotSupportedException {
                InfomationType  infomationType=null;
                try{
                    infomationType=(InfomationType)super.clone();
                    infomationType.xgMessageInfo=(XgMessageInfo)xgMessageInfo.clone();
                    return infomationType;
                }catch (Exception e){
    
                }
                return null;
            }
    }

InfomationType infomationiType  =new InfomationType();
        XgMessageInfo xgMessageInfo=new XgMessageInfo();
        infomationiType.setXgMessageInfo(xgMessageInfo);
        infomationiType.setTypeName("留言信息");
        try {
            InfomationType infomationiTypeClone=(InfomationType)infomationiType.clone();
            //Log.d("xgMessageInfoClone",xgMessageInfo.getInfoTitle());
            // Log.d("xgMessageInfoClone","clone="+xgMessageInfoClone.getInfoTitle());
            Log.d("infoTypeClone",infomationiType.toString());
            Log.d("infoTypeClone","clone="+infomationiTypeClone.toString());
            Log.d("infoTypeClone",infomationiType.typeName.toString());
            Log.d("infoTypeClone","clone="+infomationiTypeClone.typeName.toString());
            Log.d("infoTypeClone",infomationiType.xgMessageInfo.toString());
            Log.d("infoTypeClone","clone="+infomationiTypeClone.xgMessageInfo.toString());
            结果：
            **********.InfomationType@18f05097       **********.InfomationType@2aa8284
          留言信息
          clone=留言信息
          **********.XgMessageInfo@c75fa6d  //不同的对象
          **********.XgMessageInfo@1dd706a2
            infomationiTypeClone.setTypeName("资讯信息");
            infomationiTypeClone.getXgMessageInfo().setInfoTitle("某某同学....你有一条留言信息");
            Log.d("infoTypeClone",infomationiType.typeName.toString());
            Log.d("infoTypeClone","clone="+infomationiTypeClone.typeName.toString());
            Log.d("infoTypeClone",infomationiType.getXgMessageInfo().getInfoTitle()+",");
            Log.d("infoTypeClone","clone="+infomationiTypeClone.getXgMessageInfo().getInfoTitle()+",");
            //  Log.d("xgMessageInfoClone",xgMessageInfo.getInfoTitle());
            //   Log.d("xgMessageInfoClone","clone="+xgMessageInfoClone.getInfoTitle());
           结果：
           留言信息
           clone=资讯信息
           null,          //克隆对象的引用属性的改变不会影响到原型的对象的引用属性
           clone=某某同学....你有一条留言信息,
    
    
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
    }

利用serializable实现深克隆

类要实现Serializable接口 public class InfomationType implements Cloneable,Serializable，要不然会报java.io.NotSerializableException: matcheng.app.pad.datebean.InfomationType错误。
    
    在InfomationType类里添加深克隆方法
    public Object DeepClone(){
        try {
            ByteArrayOutputStream bos=new ByteArrayOutputStream();
            ObjectOutputStream oos=new ObjectOutputStream(bos);
            oos.writeObject(this);
            ByteArrayInputStream bis=new ByteArrayInputStream(bos.toByteArray());
            ObjectInputStream ois=new ObjectInputStream(bis);
            Object o=ois.readObject();;
            return o;
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return null;
    }

InfomationType infomationiType  =new InfomationType();
        XgMessageInfo xgMessageInfo=new XgMessageInfo();
        infomationiType.setXgMessageInfo(xgMessageInfo);
        infomationiType.setTypeName("留言信息");
        try {
           // InfomationType infomationiTypeClone=(InfomationType)infomationiType.clone();
           //利用Serializable实现深克隆
            InfomationType infomationiTypeClone=(InfomationType)infomationiType.DeepClone();
            //Log.d("xgMessageInfoClone",xgMessageInfo.getInfoTitle());
            // Log.d("xgMessageInfoClone","clone="+xgMessageInfoClone.getInfoTitle());
            Log.d("infoTypeClone",infomationiType.toString());
            Log.d("infoTypeClone","clone="+infomationiTypeClone.toString());
            Log.d("infoTypeClone",infomationiType.typeName.toString());
            Log.d("infoTypeClone","clone="+infomationiTypeClone.typeName.toString());
            Log.d("infoTypeClone",infomationiType.xgMessageInfo.toString());
            Log.d("infoTypeClone","clone="+infomationiTypeClone.xgMessageInfo.toString());
            结果：
           **********.InfomationType@2aa8284      **********.InfomationType@3282784e
         留言信息
         clone=留言信息
        **********.XgMessageInfo@10708d87 //XgMessageInfo类实现serializable接口，能实现深克隆
        **********.XgMessageInfo@1c892d6f
                      
      
    
          infomationiTypeClone.setTypeName("资讯信息");
          infomationiTypeClone.getXgMessageInfo().setInfoTitle("某某同学....你有一条留言信息");
          Log.d("infoTypeClone",infomationiType.typeName.toString());
          Log.d("infoTypeClone","clone="+infomationiTypeClone.typeName.toString());
          Log.d("infoTypeClone",infomationiType.getXgMessageInfo().getInfoTitle()+",");
          Log.d("infoTypeClone","clone="+infomationiTypeClone.getXgMessageInfo().getInfoTitle()+",");
         //  Log.d("xgMessageInfoClone",xgMessageInfo.getInfoTitle());
         //   Log.d("xgMessageInfoClone","clone="+xgMessageInfoClone.getInfoTitle());
        结果：
        留言信息
        clone=资讯信息
        null, //克隆对象的引用属性的改变不会影响到原型的对象的引用属性
        clone=某某同学....你有一条留言信息,
    
    
        } catch (Exception e) {
            e.printStackTrace();
        }
    }