android - Intent putExtra ArrayList <NameValuePair>

有谁知道如何将ArrayList<NameValuePair>额外添加到Intent？

ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("first_name", first_name));
nameValuePairs.add(new BasicNameValuePair("last_name", last_name));
nameValuePairs.add(new BasicNameValuePair("email", email));
nameValuePairs.add(new BasicNameValuePair("password", password));

/* Move on to step 2 */
Intent intent = new Intent(RegisterActivity1.this, RegisterActivity2.class);
intent.putExtra("nvp", nameValuePairs);
startActivity(intent);

这是RegisterActivity2的类声明:

public class RegisterActivity2 extends Activity implements Serializable {
}

logcat中的错误是:

> Parcel: unable to marshal value first_name="whatever"

实现Ted Hopp的建议后，我仍然遇到错误。这是堆栈跟踪:

08-04 22:10:16.095: E/AndroidRuntime(5065): FATAL EXCEPTION: main
> 08-04 22:10:16.095: E/AndroidRuntime(5065):
> java.lang.RuntimeException: Unable to start activity
> ComponentInfo{/.RegisterActivity2}: java.lang.RuntimeException:
> Parcelable encountered IOException reading a Serializable object (name
> = database.NVP) 08-04 22:10:16.095: E/AndroidRuntime(5065):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2070)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2095)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> android.app.ActivityThread.access$600(ActivityThread.java:135) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.app.ActivityThread$H.handleMessage(ActivityThread.java:1201)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> android.os.Handler.dispatchMessage(Handler.java:99) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.os.Looper.loop(Looper.java:137) 08-04 22:10:16.095:
> E/AndroidRuntime(5065):   at
> android.app.ActivityThread.main(ActivityThread.java:4849) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> java.lang.reflect.Method.invokeNative(Native Method) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> java.lang.reflect.Method.invoke(Method.java:511) 08-04 22:10:16.095:
> E/AndroidRuntime(5065):   at
> com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> dalvik.system.NativeStart.main(Native Method) 08-04 22:10:16.095:
> E/AndroidRuntime(5065): Caused by: java.lang.RuntimeException:
> Parcelable encountered IOException reading a Serializable object (name
> = database.NVP) 08-04 22:10:16.095: E/AndroidRuntime(5065):   at android.os.Parcel.readSerializable(Parcel.java:2144) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.os.Parcel.readValue(Parcel.java:2016) 08-04 22:10:16.095:
> E/AndroidRuntime(5065):   at
> android.os.Parcel.readListInternal(Parcel.java:2235) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.os.Parcel.readArrayList(Parcel.java:1655) 08-04 22:10:16.095:
> E/AndroidRuntime(5065):   at
> android.os.Parcel.readValue(Parcel.java:1986) 08-04 22:10:16.095:
> E/AndroidRuntime(5065):   at
> android.os.Parcel.readMapInternal(Parcel.java:2226) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.os.Bundle.unparcel(Bundle.java:223) 08-04 22:10:16.095:
> E/AndroidRuntime(5065):   at
> android.os.Bundle.getSerializable(Bundle.java:1254) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.content.Intent.getSerializableExtra(Intent.java:4268) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> .RegisterActivity2.onCreate(RegisterActivity2.java:24) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.app.Activity.performCreate(Activity.java:5244) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     at
> android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1082)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2034)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   ... 11 more 08-04
> 22:10:16.095: E/AndroidRuntime(5065): Caused by:
> java.io.InvalidClassException:
> org.apache.http.message.BasicNameValuePair; IllegalAccessException
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> java.io.ObjectStreamClass.resolveConstructorClass(ObjectStreamClass.java:694)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> java.io.ObjectStreamClass.newInstance(ObjectStreamClass.java:655)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> java.io.ObjectInputStream.readNewObject(ObjectInputStream.java:1816)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> java.io.ObjectInputStream.readNonPrimitiveContent(ObjectInputStream.java:787)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> java.io.ObjectInputStream.readObject(ObjectInputStream.java:2003)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> java.io.ObjectInputStream.readObject(ObjectInputStream.java:1960)
> 08-04 22:10:16.095: E/AndroidRuntime(5065):   at
> android.os.Parcel.readSerializable(Parcel.java:2142) 08-04
> 22:10:16.095: E/AndroidRuntime(5065):     ... 23 more

最佳答案

就像其他人指出的那样，当您希望将数组作为额外的意图传递时，元素需要实现Serializable。在您的情况下，该方法非常简单(不太完全-参见下文):定义自己的BasicNameValuePair子类并声明它以实现接口(interface)。

public class NVP extends BasicNameValuePair implements Serializable {
    public NVP(String name, String value) {
        super(name, value);
    }
}

然后，您可以像尝试过一样使用它:

ArrayList<NVP> nameValuePairs = new ArrayList<NVP>();
nameValuePairs.add(new NVP("first_name", first_name));
nameValuePairs.add(new NVP("last_name", last_name));
nameValuePairs.add(new NVP("email", email));
nameValuePairs.add(new NVP("password", password));

/* Move on to step 2 */
Intent intent = new Intent(RegisterActivity1.this, RegisterActivity2.class);
intent.putExtra("nvp", nameValuePairs);
startActivity(intent);

在接收端，您需要使用以下命令将其拉出:

ArrayList<NVP> nameValuePairs = (ArrayList<NVP>) intent.getSerializable("nvp");

编辑嗯，以上操作无效，因为BasicNameValuePair没有默认构造函数，并且序列化机制要求不可序列化的祖先类具有默认构造函数。否则，您将在反序列化方面遇到异常。

不幸的是，这意味着解决方案并不像我提出的那么简单。一种解决方法是定义自己的类以将Parcelable实现为@keerthana murugesan suggests in his answer。如果您以前曾经实现过Parcelable，那么您会感到有些痛苦。另一个解决方法是定义一个包装BasicNameValuePair的类(而不是从其派生)并管理其自己的序列化:

public class NVP implements NameValuePair, Serializable {
    private BasicNameValuePair nvp;

    public NVP(String name, String value) {
        nvp = new BasicNameValuePair(name, value);
    }

    @Override
    public String getName() {
        return nvp.getName();
    }

    @Override
    public String getValue() {
        return nvp.getValue();
    }

    // serialization support

    private static final long serialVersionUID = 1L;

    private void writeObject(ObjectOutputStream out) throws IOException {
        out.writeString(nvp.getName());
        out.writeString(nvp.getValue());
    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        nvp = new BasicNameValuePair(in.readString(), in.readString());
    }

    private void readObjectNoData() throws ObjectStreamException {
        // nothing to do
    }
}