I have ProductDetail class which contains two variables productName and productVersion. I need to replace duplicate items in the list according to the latest productVersion.
Example:
class ProductDetails {
string productName;
string productVersion;
}
new ProductDetails("ios", "9.1.0")
new ProductDetails("android", "6.0.1")
new ProductDetails("android", "5.1.1")
new ProductDetails("ios", "10.0.0")
Result: android 6.0.1 ios 10.0.0
Thanks in advance.
This should work out for you:
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Pattern;
public class ProductDetails {
private String productName;
private String productVersion;
private List<ProductDetails> productData = null;
public ProductDetails(String productName,String productVersion){
this.productName = productName;
this.productVersion = productVersion;
if(productData == null) {
productData = new ArrayList<ProductDetails>();
adNewProduct(this);
}
}
private void adNewProduct(ProductDetails p){
String[] s1 = p.productVersion.split(Pattern.quote("."));
for (ProductDetails dpp: productData) {
if (dpp.productName.equals(p.productName)) {
int index = productData.indexOf(dpp);
String[] s2 = dpp.productVersion.split(Pattern.quote("."));
for(int i = 0; i < s1.length; i++) {
int v1 = Integer.valueOf(s1[i]);
int v2 = Integer.valueOf(s2[i]);
if (v1 > v2) {
productData.set(index,p);
return;
}
}
}
}
productData.add(p);
}
@Override // you can modify it to how you want
public String toString(){
String s = "";
for (ProductDetails p: productData){
s += "ProductName: " + p.productName + " ProductVersion: " + p.productVersion + "\n";
}
return s;
}
//the main method
public static void main(String[] args) {
ProductDetails k = new ProductDetails("ios", "9.1.1");
k.adNewProduct(new ProductDetails("android", "5.1.1"));
k.adNewProduct(new ProductDetails("android", "6.0.1"));
k.adNewProduct(new ProductDetails("ios", "10.0.0"));
System.out.println(k);
}
}
Output:
ProductName: ios ProductVersion: 10.0.0
ProductName: android ProductVersion: 6.0.1
You can put all those objects into a Map<String, ProductDetails> and keep the one with the latest version.
List<ProductDetails> details = Arrays.asList(
new ProductDetails("ios", "9.1.0"),
new ProductDetails("android", "6.0.1"),
new ProductDetails("android", "5.1.1"),
new ProductDetails("ios", "10.0.0"));
// get part of version string
Function<Integer, Function<ProductDetails, Integer>> version =
n -> (pd -> Integer.valueOf(pd.getProductVersion().split("\\.")[n]));
// chain to comparator
Comparator<ProductDetails> versionComp = Comparator.comparing(version.apply(0))
.thenComparing(version.apply(1)).thenComparing(version.apply(2));
Map<String, ProductDetails> latest = new HashMap<>();
for (ProductDetails pd : details) {
String name = pd.getProductName();
if (! latest.containsKey(name) || versionComp.compare(latest.get(name), pd) < 0) {
latest.put(name, pd);
}
}
Afterwards, latest is:
{android=Sandbox.ProductDetails(productName=android, productVersion=6.0.1),
ios=Sandbox.ProductDetails(productName=ios, productVersion=10.0.0)}
Or, you can use Collectors.groupingBy and then use the same Comparator:
details.stream()
.collect(Collectors.groupingBy(ProductDetails::getProductName))
.values().stream().map(list -> Collections.max(list, versionComp))
.forEach(System.out::println);
