Array List Intent extra in Java
android, android-intent, java
Solution
But i cannot find how am ı supposed to write to get arrayList
Short answer: you can't. You can only pass `ArrayList<String>` and then retrieve it with
getIntent().getStringArrayListExtra("key");
But. If you want to pass custom objects via Intent your objects have to implement:
- `Parcelable interface` or `Serializable interface`
You can choose one of them. Both works same but have different implementations.
Parcelable interface:
If you choose Parcelable interface, your `ItemDetails` class have to implement Parcelable. Then you can put it as
intent.putParcelableArrayListExtra("key", value);
and retrieve it as:
getIntent().getParcelableArrayListExtra("key");
I won't write you Parcelable implementation because it requires a little more code. Here is nice example.
Serializable interface:
If you choose Serializable interface i suggest you to create class named for instance ItemDetailsWrapper that will wrap your `ArrayList(s)<ItemDetails>`
Both i.e. ItemDetailsWrapper and ItemDetails class have to implement Serializable interface. Now you are able to pass it via Intent like this:
getIntent().putExtra("key", <serializableClass>); // storing
getIntent().getSerializableExtra("key"); // retrieving
Example of implementation:
public class ItemDetailsWrapper implements Serializable {
private static final long serialVersionUID = 1L;
private ArrayList<ItemDetails> itemDetails;
public ItemDetailsWrapper(ArrayList<ItemDetails> items) {
this.itemDetails = items;
}
public ArrayList<ItemDetails> getItemDetails() {
return itemDetails;
}
}
public class ItemDetails implements Serializable {
private static final long serialVersionUID = 1L;
// getters, setters and properties
}
And how to pass through Activities:
ItemDetailsWrapper wrapper = new ItemDetailsWrapper(list);
Intent i = new Intent(<context>, <targetActivity>);
i.putExtra("obj", wrapper); // i.putExtra("obj", new ItemDetailsWrapper(list));
// retrieving
ItemDetailsWrapper wrap =
(ItemDetailsWrapper) getIntent().getSerializableExtra("obj");
ArrayList<ItemDetails> list = wrap.getItemDetails();
Problem
I am trying to skip my `ArrayList` through `Intent`. But I cannot find what to write in extra? Any get methods I am getting errors like "not applicable for string." Item Details: ``` public class ItemDetails { public String getName() { return name; } public void setName(String name) { this.name = name; } public String getItemDescription() { return itemDescription; } public void setItemDescription(String itemDescription) { this.itemDescription = itemDescription; } public String getPrice() { return price; } public void setPrice(String price) { this.price = price; } public int getImageNumber() { return imageNumber; } public void setImageNumber(int imageNumber) { this.imageNumber = imageNumber; } public int getVideoNumber() { return videoNumber; } public void setVideoNumber(int videoNumber) { this.videoNumber = videoNumber; } public void setChild(ArrayList<ItemDetails> item_child) { this.item_child = item_child; } public ArrayList<ItemDetails> getChild() { return this.item_child; } public void setParent(ArrayList<ItemDetails> item_parent) { this.item_parent = item_parent; } public ArrayList<ItemDetails> getParent() { return this.item_parent; } private String name ; private String itemDescription; private String price; private int imageNumber; private int videoNumber; private ArrayList<ItemDetails> item_child; private ArrayList<ItemDetails> item_parent; } ``` My class: ``` static class ViewHolder { TextView txt_itemName; TextView txt_itemDescription; TextView txt_itemPrice; ImageView itemImage; ArrayList<ItemDetails> item_parent; ArrayList<ItemDetails> item_child; } ``` My putExtra: ``` intObj.putExtra("exerciselist",obj_itemDetails.getChild()); ``` GetChild function : ``` public ArrayList<ItemDetails> getChild() { return this.item_child; } ``` But I cannot find how am I supposed to write to get arrayList? ``` ArrayList<ItemDetails> child1 = getIntent().????????? ```