代码之家 › 专栏 › 技术社区 › Jepoy

java.lang.ClassCastException:实现Parcelable时不能将java.lang.String强制转换为

classcastexception android java

Jepoy · 技术社区 · 8 年前

对于为什么我的parcelable实现会抛出classcastexception,我已经没有什么想法了。我想知道为什么会抛出异常,并想办法解决它。请让我知道,如果我仍然缺乏信息,以便你们帮助我。

IDModelDTO类

public class IdModelDTO implements Parcelable {
private String type;
private String surname;
private String givenName;
private String middleName;
private String birthDate;

protected IdModelDTO(Parcel in) {
    givenName = in.readString();
    middleName = in.readString();
    surname = in.readString();
    birthDate = in.readString();
    type = in.readString();
} 
public static final Creator<IdModelDTO> CREATOR = new Creator<IdModelDTO(){
    @Override
    public IdModelDTO createFromParcel(Parcel in) {
        return new IdModelDTO(in);
    }

    @Override
    public IdModelDTO[] newArray(int size) {
        return new IdModelDTO[size];
    }
};

@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
    dest.writeString(givenName);
    dest.writeString(middleName);
    dest.writeString(surname);
    dest.writeString(birthDate);
    dest.writeString(type);
}

@Override
public String toString() {
    return "IdModelDTO{" + "givenName='" + givenName + '\''
            + ", middleName='" + middleName + '\'' +
            "surname='" + surname + '\'' +
            "birthdate=''" + birthDate + '\'' +
            "type='" + type +  '\'' + '}';
}

这就是我用来打包的地方。在发送到下一个活动之前,我甚至可以将其作为一个包进行记录:

public void checkMplusRespCodes() {
        // Check if response codes are OK/Created:
        if(governmentIdRespCode == null){
            Log.d(TAG, "Government Id Response code: " + governmentIdRespCode );
        }
        if(saveSelfieResponse == null){
            Log.d(TAG, "saveSelfieResponse: " + saveSelfieResponse);
        }
        else if(governmentIdRespCode != null && saveSelfieResponse != null){
            if(governmentIdRespCode.equals("200") && saveSelfieResponse.equals("200")){
                //Create bundle here, then pass it to view:
                //Bundle idModelBundle = new Bundle();
                //idModelBundle.putParcelable(THISIDMODEL, thisIdModel);
                //viewContract.showNextActivity(idModelBundle);
                Log.d(TAG, " checkMplusRespCodes: " + idModelDTO.toString());
                Bundle idModelBundle = new Bundle();
                idModelBundle.putParcelable(THISIDMODEL, idModelDTO);
                viewContract.showDoneLoading();
                viewContract.showNextActivity(idModelBundle);
            }
        }

然后在NextActivity中,它抛出ClassCastException:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_test1);
    /* */
    Intent previousIntent = getIntent();
    if(previousIntent.getExtras() != null){
        Bundle previousExtras = previousIntent.getExtras();
        if(previousExtras != null){
            IdModelDTO test = previousIntent.getParcelableExtra(THISIDMODEL);
            if(test != null){
                Log.d(TAG, " asd: " + test.toString());
            }
            /* Retrieve: */
        }
    }else{
        //proceed.
    }

任何帮助都将不胜感激。

编辑: 这是该方法的日志,而我将Parcelable对象设置为一个包:

checkMplusRespCodes: IdModelDTO{givenName='test', middleName='asd'surname='Test'birthdate=''axx'type='asxd'}

异常发生在下一个活动中,在该活动中它被投射:

IdModelDTO test = previousIntent.getParcelableExtra(THISIDMODEL);

3 回复 | 直到 8 年前

Milan Pansuriya 8 年前

用这个替换你的代码

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_test1);
    /* */
    Intent previousIntent = getIntent();
    if(previousIntent.getExtras() != null){
        Bundle previousExtras = previousIntent.getExtras();
        if(previousExtras != null){
            IdModelDTO test = previousExtras.getParcelable(THISIDMODEL);
            if(test != null){
                Log.d(TAG, " asd: " + test.toString());
            }
            /* Retrieve: */
        }
    }else{
        //proceed.
    }

Jepoy 8 年前

好吧,我解决了。我正在将一个bundle对象转换到我的自定义idmodeldto中,如您在这行中看到的:

if(previousExtras != null){
        IdModelDTO test = previousIntent.getParcelableExtra(THISIDMODEL);
        ...

我删除了将对象放在包中的包部分,并使用puttera以便能够检索对象的类型:

Intent nextActivityIntent = new Intent(this, TestActivityX.class);
nextActivityIntent.putExtra(THISIDMODEL,idModelDTO);
Log.d(TAG, " Show next activity: " + idModelDTO.toString());
startActivity(nextActivityIntent);

然后检索将用于下一个活动:

Intent previousIntent = getIntent();
    if (previousIntent.getExtras() != null) {
        Bundle previousExtras = previousIntent.getExtras();
        if (previousExtras != null) {
            // Retrieve:
            if (previousExtras.containsKey(THISIDMODEL)) {
                // Re-instanciate new user.
                IdModelDTO test = previousExtras.getParcelable(THISIDMODEL);
                Log.d(TAG, " Previous Details:" + test.toString());
            }
        }
    }

谢谢各位,我真的很感谢你们的评论。

Mahesh Babariya 8 年前

我想你在分析 date 不是 String .

这就是为什么你会有这个例外。