Develop Reference

What would be the equivalent foreach loop look like in android

What would be the equivalent foreach loop look like in android java I am porting the below code to android .This for loops is working for c#.
foreach (XmlNode candidate in parent.ChildNodes)
{
if (candidate is XmlElement && candidate.Name == element.Name)
{
if (candidate == element)
{
return index;
}
index++;
}
}
below is my function for android which gets error in the for loop:
private static int FindElementIndex(Element element)
{
Node parentNode = element.getParentNode();
if (parentNode.equals(Node.DOCUMENT_NODE))
{
return 1;
}
Element parent = (Element)parentNode;
int index = 1;
//how should be the foreach of the below to be changed?
for (Node candidate : parent.getChildNodes()) {
if (candidate.equals(Node.ELEMENT_NODE) && candidate.getNodeName() == element.getNodeName())
{
if (candidate == element)
{
return index;
}
index++;
}
}
Log.d("Log_d","Couldn't find element within parent");
//throw new ArgumentException("Couldn't find element within parent");
}

// parent.ChilNodes is some type of colleciton like arraylist
some update it show be for not foreach
for(XmlNode candidate : parent.ChildNodes)
{
if (candidate instanceOf XmlElement && candidate.Name == element.Name)
{
if (candidate == element)
{
return index;
}
index++;
}
}

I changed the function and for loop in the function like this
private static int FindElementIndex(Element element)
{
Node parentNode = element.getParentNode();
if (parentNode.equals(Node.DOCUMENT_NODE))
{
return 1;
}
Element parent = (Element)parentNode;
int index = 1;
NodeList nodes = parent.getChildNodes();
for (int k = 0; k < nodes.getLength(); k++) {
Node candidate = nodes.item(k);
if (candidate.equals(Node.ELEMENT_NODE) && candidate.getNodeName() == element.getNodeName()) {
return index;
}
index++;
}
Log.d("Log_d","Couldn't find element within parent");
//throw new ArgumentException("Couldn't find element within parent");
return 0;
}

Comparison of app version

How to compare app version in android
I got latest version code and current version code , but the problem is
current version is 1.0
and latest version is 1.0.0
so how to compare that float value in android

I have written a small Android library for comparing version numbers: https://github.com/G00fY2/version-compare
What it basically does is this:
public int compareVersions(String versionA, String versionB) {
String[] versionTokensA = versionA.split("\\.");
String[] versionTokensB = versionB.split("\\.");
List<Integer> versionNumbersA = new ArrayList<>();
List<Integer> versionNumbersB = new ArrayList<>();
for (String versionToken : versionTokensA) {
versionNumbersA.add(Integer.parseInt(versionToken));
}
for (String versionToken : versionTokensB) {
versionNumbersB.add(Integer.parseInt(versionToken));
}
final int versionASize = versionNumbersA.size();
final int versionBSize = versionNumbersB.size();
int maxSize = Math.max(versionASize, versionBSize);
for (int i = 0; i < maxSize; i++) {
if ((i < versionASize ? versionNumbersA.get(i) : 0) > (i < versionBSize ? versionNumbersB.get(i) : 0)) {
return 1;
} else if ((i < versionASize ? versionNumbersA.get(i) : 0) < (i < versionBSize ? versionNumbersB.get(i) : 0)) {
return -1;
}
}
return 0;
}
This snippet doesn't offer any error checks or handling. Beside that my library also supports suffixes like "1.2-rc" > "1.2-beta".

I am a bit late to the party but I have a great solution for all of you!
1. Use this class:
public class VersionComparator implements Comparator {
public boolean equals(Object o1, Object o2) {
return compare(o1, o2) == 0;
}
public int compare(Object o1, Object o2) {
String version1 = (String) o1;
String version2 = (String) o2;
VersionTokenizer tokenizer1 = new VersionTokenizer(version1);
VersionTokenizer tokenizer2 = new VersionTokenizer(version2);
int number1, number2;
String suffix1, suffix2;
while (tokenizer1.MoveNext()) {
if (!tokenizer2.MoveNext()) {
do {
number1 = tokenizer1.getNumber();
suffix1 = tokenizer1.getSuffix();
if (number1 != 0 || suffix1.length() != 0) {
// Version one is longer than number two, and non-zero
return 1;
}
}
while (tokenizer1.MoveNext());
// Version one is longer than version two, but zero
return 0;
}
number1 = tokenizer1.getNumber();
suffix1 = tokenizer1.getSuffix();
number2 = tokenizer2.getNumber();
suffix2 = tokenizer2.getSuffix();
if (number1 < number2) {
// Number one is less than number two
return -1;
}
if (number1 > number2) {
// Number one is greater than number two
return 1;
}
boolean empty1 = suffix1.length() == 0;
boolean empty2 = suffix2.length() == 0;
if (empty1 && empty2) continue; // No suffixes
if (empty1) return 1; // First suffix is empty (1.2 > 1.2b)
if (empty2) return -1; // Second suffix is empty (1.2a < 1.2)
// Lexical comparison of suffixes
int result = suffix1.compareTo(suffix2);
if (result != 0) return result;
}
if (tokenizer2.MoveNext()) {
do {
number2 = tokenizer2.getNumber();
suffix2 = tokenizer2.getSuffix();
if (number2 != 0 || suffix2.length() != 0) {
// Version one is longer than version two, and non-zero
return -1;
}
}
while (tokenizer2.MoveNext());
// Version two is longer than version one, but zero
return 0;
}
return 0;
}
// VersionTokenizer.java
public static class VersionTokenizer {
private final String _versionString;
private final int _length;
private int _position;
private int _number;
private String _suffix;
private boolean _hasValue;
VersionTokenizer(String versionString) {
if (versionString == null)
throw new IllegalArgumentException("versionString is null");
_versionString = versionString;
_length = versionString.length();
}
public int getNumber() {
return _number;
}
String getSuffix() {
return _suffix;
}
public boolean hasValue() {
return _hasValue;
}
boolean MoveNext() {
_number = 0;
_suffix = "";
_hasValue = false;
// No more characters
if (_position >= _length)
return false;
_hasValue = true;
while (_position < _length) {
char c = _versionString.charAt(_position);
if (c < '0' || c > '9') break;
_number = _number * 10 + (c - '0');
_position++;
}
int suffixStart = _position;
while (_position < _length) {
char c = _versionString.charAt(_position);
if (c == '.') break;
_position++;
}
_suffix = _versionString.substring(suffixStart, _position);
if (_position < _length) _position++;
return true;
}
}
}
2. create this function
private fun isNewVersionAvailable(currentVersion: String, latestVersion: String): Boolean {
val versionComparator = VersionComparator()
val result: Int = versionComparator.compare(currentVersion, latestVersion)
var op = "=="
if (result < 0) op = "<"
if (result > 0) op = ">"
System.out.printf("%s %s %s\n", currentVersion, op, latestVersion)
return if (op == ">" || op == "==") {
false
} else op == "<"
}
3. and just call it by
e.g. isNewVersionAvailable("1.2.8","1.2.9") where 1.2.8 is your current version here and 1.2.9 is the latest version, which returns true!

Why overcomplicate this so much?
Just scale the major, minor, patch version and you have it covered:
fun getAppVersionFromString(version: String): Int { // "2.3.5"
val versions = version.split(".") // [2, 3, 5]
val major = versions[0].toIntOrDefault(0) * 10000 // 20000
val minor = versions[1].toIntOrDefault(0) * 1000 // 3000
val patch = versions[2].toIntOrDefault(0) * 100 // 500
return major + minor + patch // 2350
}
That way when you compare e.g 9.10.10 with 10.0.0 the second one is greater.

Use the following method to compare the versions number:
Convert float to String first.
public static int versionCompare(String str1, String str2) {
String[] vals1 = str1.split("\\.");
String[] vals2 = str2.split("\\.");
int i = 0;
// set index to first non-equal ordinal or length of shortest version string
while (i < vals1.length && i < vals2.length && vals1[i].equals(vals2[i])) {
i++;
}
// compare first non-equal ordinal number
if (i < vals1.length && i < vals2.length) {
int diff = Integer.valueOf(vals1[i]).compareTo(Integer.valueOf(vals2[i]));
return Integer.signum(diff);
}
// the strings are equal or one string is a substring of the other
// e.g. "1.2.3" = "1.2.3" or "1.2.3" < "1.2.3.4"
return Integer.signum(vals1.length - vals2.length);
}
Refer the following SO question : Efficient way to compare version strings in Java

Android ArrayList compare

Hi guys i got 2 ArrayList based on same class. I have to add from arraylist1 to arraylist2 non exist(s)ing rows. I tried to use contains but its always returning false. What i m doing wrong ? Ty
MyClass
public class HataKoduBean {
private String Oid;
private String Name;
private String Surname;
}
How i define Arraylists
Arraylist<MyClass> array1 = new Arraylist<>();
Arraylist<MyClass> array2 = new Arraylist<>();
How i tried to compare ?
for (int ii = 0; ii < array1.size(); ii++) {
if (!array2.contains(array1.get(ii)))
array2.add(array1.get(ii));
}

First you have to implement equals() and hashCode() in your custom class.
Consider to use Sets, so you can merge collections in one line with addAll().

First you have to implement equals() and hashCode() in your custom object
and create loop and compare between object by using equals method like this.
implement equals and hashCode:
`#Override
public boolean equals(Object o) {
if (this == o)
return true;
if (o == null || getClass() != o.getClass())
return false;
HataKoduBean o = (HataKoduBean) o;
return Oid != null?Oid.equals(HataKoduBean.Oid):HataKoduBean.Oid== null;
}
#Override
public int hashCode() {
return Oid != null ? Oid.hashCode() : 0;
}`
compare Objects:
for (int ii = 0; ii < array1.size(); ii++) {
if (!array2.get(ii).equals(array1.get(ii)))
array2.add(array1.get(ii));
}

ArrayIndexOutOfBoundsException when parceling set of enums

I can't see the error, I'm having this problem for a long time already... My parcelable class crashes if it is recreated, but I can't find the problem...
I checked the order of writing/reading data.
I checked the functions I use (direct reading/writing vs my custum null save functions)
I marked the line in the first code block that created following exception: java.lang.ArrayIndexOutOfBoundsException: length=5; index=5
SHORT CODE
private Set<ContactType> mMatchesDataLoaded = new HashSet<ContactType>();
saving the set
dest.writeInt(mMatchesDataLoaded.size());
Iterator<ContactType> it = mMatchesDataLoaded.iterator();
while (it.hasNext())
dest.writeInt(it.next().ordinal());
reading the set
int count = source.readInt();
for (int i = 0; i < count; i++)
// ---------------------------------------------------------------------------
// next line produces EXCEPTION!!! java.lang.ArrayIndexOutOfBoundsException: length=5; index=5
// ---------------------------------------------------------------------------
mMatchesDataLoaded.add(ContactType.values()[source.readInt()]);
FULL CODE
I can't see any problems or rather where the problem is...
public class ContactPhone implements Parcelable
{
public static enum ContactType
{
WhatsApp,
Viber,
GooglePlus,
Twitter,
Instagram
}
private boolean mIsUserProfile = false;
private boolean mHasImage;
private int mId;
private long mRawId;
private String mName = null;
private List<PhoneNumber> mNumbers = new ArrayList<PhoneNumber>();
private DBPhoneContact mDBContact = null;
private Set<ContactType> mMatchesDataLoaded = new HashSet<ContactType>();
private HashMap<ContactType, List<BaseMatchContact>> mMatchesData = new HashMap<ContactType, List<BaseMatchContact>>();
// ----------------------
// Parcelable
// ----------------------
#Override
public void writeToParcel(Parcel dest, int flags)
{
ParcelBundleUtils.writeBoolean(dest, mIsUserProfile);
ParcelBundleUtils.writeBoolean(dest, mHasImage);
ParcelBundleUtils.writeIntegerNullSafe(dest, mId);
ParcelBundleUtils.writeLongNullSafe(dest, mRawId);
ParcelBundleUtils.writeStringNullSafe(dest, mName);
dest.writeList(mNumbers);
ParcelBundleUtils.writeLongNullSafe(dest, mDBContact != null ? mDBContact.getId() : null);
// save set
dest.writeInt(mMatchesDataLoaded.size());
Iterator<ContactType> it = mMatchesDataLoaded.iterator();
while (it.hasNext())
dest.writeInt(it.next().ordinal());
// save HashMap
dest.writeInt(mMatchesData.size());
for (Map.Entry<ContactType, List<BaseMatchContact>> entry : mMatchesData.entrySet())
{
dest.writeInt(entry.getKey().ordinal());
dest.writeInt(entry.getValue().size());
for (int i = 0; i < entry.getValue().size(); i++)
dest.writeParcelable(entry.getValue().get(i), 0);
}
}
public void readFromParcel(Parcel source)
{
mIsUserProfile = ParcelBundleUtils.readBoolean(source);
mHasImage = ParcelBundleUtils.readBoolean(source);
mId = ParcelBundleUtils.readIntegerNullSafe(source);
mRawId = ParcelBundleUtils.readLongNullSafe(source);
mName = ParcelBundleUtils.readStringNullSafe(source);
source.readList(mNumbers, PhoneNumber.class.getClassLoader());
Long id = ParcelBundleUtils.readLongNullSafe(source);
mDBContact = null;
if (id != null)
mDBContact = MainApp.getDS().getDBPhoneContactDao().load(id);
// read set
int count = source.readInt();
for (int i = 0; i < count; i++)
// ---------------------------------------------------------------------------
// next line produces EXCEPTION!!! java.lang.ArrayIndexOutOfBoundsException: length=5; index=5
// ---------------------------------------------------------------------------
mMatchesDataLoaded.add(ContactType.values()[source.readInt()]);
// read HashMap
count = source.readInt();
for (int i = 0; i < count; i++)
{
ContactType type = ContactType.values()[source.readInt()];
Class<?> clazz = BaseDef.getMatchClass(type);
// L.d(this, "Classloader: " + clazz.getName() + " type: " + type.name());
int size = source.readInt();
List<BaseMatchContact> list = new ArrayList<BaseMatchContact>();
for (int j = 0; j < size; j++)
list.add((BaseMatchContact) source.readParcelable(clazz.getClassLoader()));
mMatchesData.put(type, list);
}
}
}
The PhoneNumber class implements parcelable and is quite simple and read/writes like following:
#Override
public void writeToParcel(Parcel dest, int flags)
{
ParcelBundleUtils.writeStringNullSafe(dest, mName);
ParcelBundleUtils.writeStringNullSafe(dest, mNormNumber);
ParcelBundleUtils.writeStringNullSafe(dest, mNumber);
}
public void readFromParcel(Parcel source)
{
mName = ParcelBundleUtils.readStringNullSafe(source);
mNormNumber = ParcelBundleUtils.readStringNullSafe(source);
mNumber = ParcelBundleUtils.readStringNullSafe(source);
}
And here are my helper functions:
public static void writeBoolean(Parcel p, boolean b)
{
p.writeByte((byte) (b ? 1 : 0));
}
public static boolean readBoolean(Parcel p)
{
return p.readByte() == 1;
}
public static void writeStringNullSafe(Parcel p, String s)
{
p.writeByte((byte) (s != null ? 1 : 0));
if (s != null)
p.writeString(s);
}
public static void writeIntegerNullSafe(Parcel p, Integer i)
{
p.writeByte((byte) (i != null ? 1 : 0));
if (i != null)
p.writeInt(i);
}
public static void writeLongNullSafe(Parcel p, Long l)
{
p.writeByte((byte) (l != null ? 1 : 0));
if (l != null)
p.writeLong(l);
}
public static void writeDoubleNullSafe(Parcel p, Double d)
{
p.writeByte((byte) (d != null ? 1 : 0));
if (d != null)
p.writeDouble(d);
}
public static void writeParcelableNullSafe(Parcel p, Parcelable d, int flags)
{
p.writeByte((byte) (d != null ? 1 : 0));
if (d != null)
p.writeParcelable(d, flags);
}
public static String readStringNullSafe(Parcel p)
{
boolean isPresent = p.readByte() == 1;
return isPresent ? p.readString() : null;
}
public static Integer readIntegerNullSafe(Parcel p)
{
boolean isPresent = p.readByte() == 1;
return isPresent ? p.readInt() : null;
}
public static Long readLongNullSafe(Parcel p)
{
boolean isPresent = p.readByte() == 1;
return isPresent ? p.readLong() : null;
}
public static Double readDoubleNullSafe(Parcel p)
{
boolean isPresent = p.readByte() == 1;
return isPresent ? p.readDouble() : null;
}
#SuppressWarnings("unchecked")
public static <T extends Parcelable> T readParcelableNullSafe(Parcel p, ClassLoader classLoader)
{
boolean isPresent = p.readByte() == 1;
return isPresent ? (T) p.readParcelable(classLoader) : null;
}

int count = source.readInt(); // index is raised + 1
for (int i = 0; i < count; i++)
mMatchesDataLoaded.add(ContactType.values()[source.readInt()]); // index is raised by 1, starting with 1!
you loop from 0 to 4, but source.readInt() was already called once, so you called it 5 times in total.

ContactType contains 5 values, from index 0 to index 4. You are trying to access the index 5, which does not exist.
mMatchesDataLoaded.add(ContactType.values()[source.readInt()]);
source.readInt() gives you a 5, try to figure out, with debug, why does it contain this value.
My guess is that writeToParcel writes this 5, try to inspect mMatchesDataLoaded which maybe contains some additional unwanted data.

Indexable Listview in Android

I'm trying to get an indexable list in my list view. I referred this. But while using the code, I'm facing with an error while using Korean Characters in the StringMatcher class. Can anyone explain me the usage of this class? Is this class required for English Characters as well?
Thanks in advance.

There are some changes to be done to make it work. In order to compile the project and get rid of korean text update the StringMatcher class
package com.woozzu.android.util;
public class StringMatcher {
public static boolean match(String value, String keyword) {
if (value == null || keyword == null)
return false;
if (keyword.length() > value.length())
return false;
int i = 0, j = 0;
do {
int vi = value.charAt(i);
int kj = keyword.charAt(j);
if (isKorean(vi) && isInitialSound(kj)) {
} else {
if (vi == kj) {
i++;
j++;
} else if (j > 0)
break;
else
i++;
}
} while (i < value.length() && j < keyword.length());
return (j == keyword.length())? true : false;
}
private static boolean isKorean(int i) {
return false;
}
private static boolean isInitialSound(int i) {
return false;
}
}