Java 如何将包含任意类型的对象发送到另一个活动？

我对Android编程相当陌生，我也遇到过这个问题

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

我有一个对象正试图发送到一个新活动中，它是此类的一个实例：

public final class BusinessEntity extends com.google.api.client.json.GenericJson {

/**
 * The value may be {@code null}.
 */
@com.google.api.client.util.Key
private Contact contact;

/**
 * The value may be {@code null}.
 */
@com.google.api.client.util.Key
@com.google.api.client.json.JsonString
private java.lang.Long id;

/**
 * The value may be {@code null}.
 */
@com.google.api.client.util.Key
private java.lang.String imageUrl;

/**
 * The value may be {@code null}.
 */
@com.google.api.client.util.Key
private Person owner;

/**
 * The value may be {@code null}.
 */
@com.google.api.client.util.Key
private java.util.List<java.lang.String> tag;

/**
 * The value may be {@code null}.
 */
@com.google.api.client.util.Key
private java.lang.String type;

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

这是我在第二节课上学到的：

Bundle b = getIntent().getExtras();
String json = b.getString("business");

Gson gson = new Gson();
JsonParser parser = new JsonParser();
JsonArray array = parser.parse(json).getAsJsonArray();

Contact contact = gson.fromJson(array.get(0), Contact.class);
Long id = gson.fromJson(array.get(1), Long.class);
String imageURL = gson.fromJson(array.get(2), String.class);
Person person = gson.fromJson(array.get(3), Person.class);
List<String> tag = gson.fromJson(array.get(4), List.class);

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

以及实施：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

在DetailsActivity类中：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

        Intent i = getIntent();
        Bundle b = i.getExtras();
        business = (SimpleBusiness)b.get("business");

谢谢你们的帮助。如果没有你们给我的建议，我可能会花更长的时间

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

--------------------------------------------编辑2--------------------------------------------

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

切换到使用EventBus直接传递BusinessEntity对象。简单多了。

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

传递对象：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

Intent i = new Intent(mActivity, DetailsActivity.class);
BusinessEntity business = businesses.get(position);
de.greenrobot.event.EventBus.getDefault().postSticky(business);
startActivity(i);

检索对象： @凌驾

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.busEntity = (BusinessEntity) EventBus.getDefault().removeStickyEvent(BusinessEntity.class);
    setContentView(R.layout.activity_details);
}

---

如果您能够修改BusinessEntity，那么让它实现

Serializable

。然后，您可以将该业务作为额外业务：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

//To put the object as an extra
...
BusinessEntity business = businesses(get(position));
Intent intent = new Intent(mActivity, DetailsActivity.class);
intent.putExtra("business", business); // Where business is now a `Serializable`
...

//To retrieve the object (in your second class). 
//TODO -- Include check to see if intent has the extra first
BusinessEntity retrievedBusiness = (BusinessEntity) intent.getSerializableExtra("business")

---

您应该使用可包裹的对象

---

您可以通过

Serializable

接口执行此操作。只需让您的

BusinessEntity

实现可序列化，如下所示：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

public final class BusinessEntity extends com.google.api.client.json.GenericJson implements Serializable {
     //your code here
     ...
     ...
}

然后创建您的意图并添加额外的内容：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

Intent i = new Intent(mActivity, DetailsActivity.class);
i.putExtra("BusinessEntity", yourBuisnessEntityObject);
startActivity(i);

最后，在您的详细活动中：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

BusinessEntity business = (BusinessEntity) getIntent().getSerializableExtra("BusinessEntity");

瞧！您拥有详细的BusinessEntity对象活动

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

编辑：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

回到您的代码，我认为问题在于您放置了一个JsonObject额外对象，而不是JsonArray。你应该做与你第一次发布的相同的事情，但有一个更正：

        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);

---

JsonObject object=parser.parse（json.getAsJsonObject（）然后通过键将其解析为JsonObject。
EventBus使您的生活变得更加轻松，请参阅我对这个问题的回答中的示例和链接：本质上，不需要进行任何序列化或任何操作，只需将对象放在EventBus上，然后在代码中的任何位置（在另一个活动、片段、服务等中）再次获取它即可
它不是一个
JsonArray
我想，它一定是一个
JsonObject
是这样吗？无论你做什么，都不要将它设置为静态引用：（EventBus让您的生活变得更加轻松，请参阅我回答这个问题时的示例和链接：本质上，不需要进行任何序列化或任何操作，只需将对象放在EventBus上，然后在代码中的任何位置（在另一个活动、片段、服务等中）再次获取它即可。）@cYrixmorten哇，这正是我需要的。谢谢。很高兴我能帮上忙；）这是我见过的最简单但功能极其强大的工具之一。可能还想研究一下ButterKnife，用于视图注入，Dagger用于整个类的依赖项注入（Dagger一开始有点复杂，但非常简洁）例如，如果我需要GPS位置，我需要在代码中编写
@InjectLocationsModule LocationsModule
。所有这些工具都可以大大减少代码行数，并使其更易于维护。我得到一个java.lang.ClassCastException:java.util.HashMap无法转换为classpath.BusinessEntity是否传递了业务（HashMap）代替业务（业务实体）？不只是BusinessEntity businessI将尝试此操作，但这意味着我需要编辑所有3个类，BusinessEntity、Contact和Person，以实现ParcelableFine，请给出对您有效的答案，以便对其他人有所帮助。我得到一个java.lang.ClassCastException:java.util.HashMap无法转换为类路径。BusinessEntity@swanhella其中我ine？
BusinessEntity business=（BusinessEntity）getIntent（）.getSerializableExtra（“BusinessEntity”）；
如何将一个businessObject放入intent？您能提供该对象吗？
intent i=newintent（mActivity，DetailsActivity.class）；
BusinessEntity BusinessEntity business=businesses.get（position）；
i.puttera(“BusinessEntity”，business）；
startActivity（i）；
        Intent i = new Intent(mActivity, DetailsActivity.class);
        Bundle b = new Bundle();

        BusinessEntity business = businesses.get(position);
        SimpleBusiness simpleBusiness = new SimpleBusiness(business);
        i.putExtra("business", simpleBusiness);
        //i.putExtras(b);
        startActivity(i);