Android Parcelable – RetailerOrderActivity.java返回null

我必须将一项活动传递给另一项活动：

我有SalesProduct enetity类：

public class Product implements Parcelable{ private double availableQuantity; private double price; private String productCode; private String description; private String description2; private String productGroup; private String alternateSearch; private String productTypeCode; private String nonStockItemFlag; private String salableFlag; private double weight; private double qty; private double grossValue; private double value; private ArrayList<Product> product; public Product() { } public Product(Parcel in) { this(); readFromParcel(in); } /* * Constructor calls read to create object */ private void readFromParcel(Parcel in) { in.readTypedList(product, Product.CREATOR); /* NULLPOINTER HERE */ } public int describeContents() { return 0; } public void writeToParcel(Parcel dest, int flags) { dest.writeList(product); } public static final Parcelable.Creator<Product> CREATOR = new Parcelable.Creator<Product>() { public Product createFromParcel(Parcel in) { Product prod = new Product(); Bundle b = in.readBundle(Product.class.getClassLoader()); prod.product = b.getParcelableArrayList("enteredProduct"); return prod; } public Product[] newArray(int size) { return new Product[size]; } }; /** * @param product */ public Product(ArrayList<Product> product) { this.product = product; } /** * @param availableQuantity * @param price * @param productCode * @param description * @param nonStockItemFlag * @param kitProductFlag * @param qty * @param grossValue * @param value */ public Product(double availableQuantity, double price, String productCode, String description, String nonStockItemFlag, double qty, double value) { super(); this.availableQuantity = availableQuantity; this.price = price; this.productCode = productCode; this.description = description; this.nonStockItemFlag = nonStockItemFlag; this.qty = qty; this.value = value; } public ArrayList<Product> getProduct() { return product; } public void setProduct(ArrayList<Product> product) { this.product = product; } public double getValue() { return value; } public void setValue(double value) { this.value = value; } public double getGrossValue() { return grossValue; } public void setGrossValue(double grossValue) { this.grossValue = grossValue; } public double getQty() { return qty; } public void setQty(double qty) { this.qty = qty; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public double getAvailableQuantity() { return availableQuantity; } public void setAvailableQuantity(double availableQuantity) { this.availableQuantity = availableQuantity; } public String getProductCode() { return productCode; } public void setProductCode(String productCode) { this.productCode = productCode; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public String getDescription2() { return description2; } public void setDescription2(String description2) { this.description2 = description2; } public String getProductGroup() { return productGroup; } public void setProductGroup(String productGroup) { this.productGroup = productGroup; } public String getAlternateSearch() { return alternateSearch; } public void setAlternateSearch(String alternateSearch) { this.alternateSearch = alternateSearch; } public String getProductTypeCode() { return productTypeCode; } public void setProductTypeCode(String productTypeCode) { this.productTypeCode = productTypeCode; } public String getNonStockItemFlag() { return nonStockItemFlag; } public void setNonStockItemFlag(String nonStockItemFlag) { this.nonStockItemFlag = nonStockItemFlag; } public String getSalableFlag() { return salableFlag; } public void setSalableFlag(String salableFlag) { this.salableFlag = salableFlag; } public double getWeight() { return weight; } public void setWeight(double weight) { this.weight = weight; } } 

和来电者活动：

  if(productMap.size() >0){ ArrayList<Product> enteredProductList = new ArrayList<Product>(productMap.values()); Bundle b = new Bundle(); Product pr =new Product(enteredProductList); b.putParcelableArrayList("enteredProduct", enteredProductList); Intent showContent = new Intent(getApplicationContext(),RetailerOrderIActivity.class); showContent.putExtras(b); //Insert the Bundle object in the Intent' Extras startActivity(showContent); }else{ Toast.makeText(RetailerOrderActivity.this," You don't have invoice records" ,Toast.LENGTH_SHORT).show(); } 

并接收部分：

  public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.order_main); Bundle b = this.getIntent().getExtras(); ArrayList<Product> p = b.getParcelableArrayList("enteredProduct"); System.out.println("-- RetailerOrderIActivity --" + p.size()); for (Product s : p) { System.out.println(" --Qty-" + s.getQty()); System.out.println(" --price -" + s.getPrice()); System.out.println(" --code -" + s.getProductCode()); } 

这是我的错误部分：

  09-13 16:22:43.236: ERROR/AndroidRuntime(343): FATAL EXCEPTION: main 09-13 16:22:43.236: ERROR/AndroidRuntime(343): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.xont.controller/com.xont.controller.sales.RetailerOrderIActivity}: java.lang.NullPointerException 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Handler.dispatchMessage(Handler.java:99) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Looper.loop(Looper.java:123) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.app.ActivityThread.main(ActivityThread.java:3683) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at java.lang.reflect.Method.invokeNative(Native Method) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at java.lang.reflect.Method.invoke(Method.java:507) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at dalvik.system.NativeStart.main(Native Method) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): Caused by: java.lang.NullPointerException 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at com.xont.entity.Product$1.createFromParcel(Product.java:94) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at com.xont.entity.Product$1.createFromParcel(Product.java:1) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Parcel.readParcelable(Parcel.java:1981) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Parcel.readValue(Parcel.java:1846) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Parcel.readListInternal(Parcel.java:2092) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Parcel.readArrayList(Parcel.java:1536) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Parcel.readValue(Parcel.java:1867) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Parcel.readMapInternal(Parcel.java:2083) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Bundle.unparcel(Bundle.java:208) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.os.Bundle.getParcelableArrayList(Bundle.java:1144) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at com.xont.controller.sales.RetailerOrderIActivity.onCreate(RetailerOrderIActivity.java:18) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 09-13 16:22:43.236: ERROR/AndroidRuntime(343): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 

请帮助我..它返回null …哪里错了请在这个意见我？

提前致谢

Answer 1

这是你如何传递一个ArrayList，因为我试过了。

MyListClass.java – 自定义类

 public class MyListClass implements Parcelable{ private int test; public MyListClass() {} public MyListClass(Parcel read){ test = read.readInt(); } public int getTest() { return test; } public void setTest(int test) { this.test = test; } public static final Parcelable.Creator<MyListClass> CREATOR = new Parcelable.Creator<MyListClass>() { @Override public MyListClass createFromParcel(Parcel source) { return new MyListClass(source); } @Override public MyListClass[] newArray(int size) { return new MyListClass[size]; } }; @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel arg0, int arg1) { arg0.writeInt(test); } } 

MyParcelable.java

 public class MyParcelable implements Parcelable { private List<MyListClass> arrList = new ArrayList<MyListClass>(); private int myInt = 0; private String str = null; public String getStr() { return str; } public void setStr(String str) { this.str = str; } public List<MyListClass> getArrList() { return arrList; } public void setArrList(List<MyListClass> arrList) { this.arrList = arrList; } public int getMyInt() { return myInt; } public void setMyInt(int myInt) { this.myInt = myInt; } MyParcelable() { // initialization arrList = new ArrayList<MyListClass>(); } public MyParcelable(Parcel in) { myInt = in.readInt(); str = in.readString(); in.readTypedList(arrList, MyListClass.CREATOR); } @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel outParcel, int flags) { outParcel.writeInt(myInt); outParcel.writeString(str); outParcel.writeTypedList(arrList); } public static final Parcelable.Creator<MyParcelable> CREATOR = new Parcelable.Creator<MyParcelable>() { @Override public MyParcelable createFromParcel(Parcel in) { return new MyParcelable(in); } @Override public MyParcelable[] newArray(int size) { return new MyParcelable[size]; } }; } 

MainAcitivty.java

 @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); arrList.add(new MyListClass()); arrList.get(0).setTest(200); MyParcelable object = new MyParcelable(); object.setMyInt(100); object.setArrList(arrList); Intent intent = new Intent(MainActivity.this,ReceiverParcel.class); intent.putExtra("parcel", object); startActivity(intent); } 

ReceiverParcel.java

 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Bundle b = getIntent().getExtras(); MyParcelable object = b.getParcelable("parcel"); System.out.println(object.getArrList().get(0).getTest()); System.out.println(object.getMyInt()); }