How do we convert multi value map to CSV, i am able to do with the single key - value map. But facing issue with multi value map.
I do convert key value using this
private String getCSVRow(Set<String> headers, Map<String, String> map) {
List<String> items = new ArrayList<String>();
for (String header : headers) {
String value = map.get(header) == null ? "" : map.get(header).replace(",", "");
items.add(value);
}
return StringUtils.join(items.toArray(), ",");
}
In this if i want to put Map<String, List<String>> as i parameter how will i do it?
create a method that will convert List to String, and call that method from the for loop. So your code becomes
for (String header : headers) {
String value = map.get(header) == null ? "" : generateStringFromList(map.get(header));
items.add(value);
}
private String generateStringFromList(List<String> list) {
// create the code here
}
Related
Is there a code for finding a specific value in a hashmap?
I want to use a for loop to convert values in a hashmap into an int.
for (int i = 0; i < items; i++) {
cost = Integer.parseInt(myHashmap);
}
can I even use .parseInt on a hashmap or is there another way to convert a place in a hashmap into a int?
Like String[3] is there a code to find a specific place in a hashmap?
To iterate over all values of a map, use the values method:
Map<Long, String> map = ...;
for (final String value = map.values()) {
System.out.println(value);
}
To find a specific value, iterate all values, check against your predicate and return if found:
String findValue(final Map<Long, String> map, final Predicate<String> condition) {
for (final String value = map.values()) {
if (condition.test(value)) {
return value;
}
}
return null;
}
To find the key for a given value, iterate the entry set of the map:
Long findKey(final Map<Long, String> map, final String value) {
for (final Map.Entry<Long, String> entry = map.entrySet()) {
if (Objects.equals(entry.getValue(), value)) {
return entry.getKey();
}
}
return null;
}
Of course, once you have a value (or a key), you can use it any way you like. That includes passing it as argument to Integer.parseInt.
myHashmap.values() will return all the values of the Map. Integer.parseInt(value) parses the String argument as a signed decimal integer object.
public static void main(String[] args) {
Map<String, String> myHashmap = new HashMap<>();
myHashmap.put("A", "10");
myHashmap.put("B", "20");
myHashmap.put("C", "30");
myHashmap.values().forEach(value -> {
System.out.println(Integer.parseInt(value));
// Rest of the logic
});
}
I know hashMap overwrites the kay, but I really need the same key to be provided for another value. What is also the issue is that in the postRequest further down, it needs to be set as a Map value.
So how can the below be fixed so that the body contains all the field and their values below as displayed in the table?
So we can't have field3 = tree, cone, it has to be field 3 = tree, field 3 = cone or the service will fail.
Example step:
|field |value |
|----------|--------------------------------------------|
|field1 |shop |
|field2 |apple |
|field3 |tree |
|field3 |cone |
#Step("Example step: <table>")
public void exampleStep(Table table) {
Map<String, Object> body = new HashMap<>();
table.getTableRows().forEach(row -> {
String value = row.getCell(VALUE);
String field = row.getCell(FIELD);
body.put(field, value);
});
final String url = String.format("%s/service/%s", System.getenv(ENDPOINT), service);
new DBrequest(dataStore, url, HttpMethod.POST).postRequest(body);
If you have a Map<String, List<String>> for example, you have to check if keys are present when you are inputting values, see this:
#Step("Example step: <table>")
public void exampleStep(Table table) {
table.getTableRows().forEach(row -> {
String value = row.getCell(VALUE);
String field = row.getCell(FIELD);
// you have to check if the key is already present
if (body.containsKey(field)) {
// if it is, you can simply add the new value to the present ones
body.get(field).add(value);
} else {
// otherwise you have to create a new list
List<String> values = new ArrayList<>();
// add the value to it
values.add(value);
// and then add the list of values along with the key to the map
body.put(field, values);
}
});
}
You can iterate such a Map in several ways, one is this:
for (Entry<String, List<String>> entry : body.entrySet()) {
// print the key first
System.out.println(entry.getKey() + ":");
// then iterate the value (which is a list)
for (String value : entry.getValue()) {
// and print each value of that list
System.out.println("\t" + value);
}
};
}
Please note:
This is a simple example without any content and it doesn't handle any casting from Object.
I need perform an hashmap iteration using Java 8 streams. I need to iterate over an hashmap. Check whether a particular key ("new") does not have null or empty values, copy that value to a variable (String val1) of type string. Then again check for another key for ex:"old" and then copy that value to a variable (String val2) of type string and call the main method where i need to send these 2 values (val1, val2). This has to be done with in hashmap iteration. Can you please help me on this.
The code:
map1.entrySet()
.stream()
.filter(s -> {
if (s.getKey().contains("abc") && !s.getValue().equals("") && s.getValue()!=null) {
String val1 = s.getValue;
if (s.getKey().contains("bb")) {
String val2 = s.getValue(); //call the function
callFunction(val1,val2);
}
}
else {
}
});
Need to be done using Java 8
for(Map.Entry e : map1.entrySet()) {
if(e.containsKey("new")&& !e.getValue().equals("")){
String val1 = (String) e.getValue();
if(e.containsKey("old")&& !e.getValue().equals("")){
String val2 = (String) e.getValue();
//call the function-- This is boolean
if(validateMethod(val1, val2)){ // if true
Map<String, String> map2 = new HashMap<>();
map2.putAll(e);
}
}
}
}
You need to look for particular keys : new and old so you don't need to iterate over the entries of the map, because if the keys exist they will be unique.
get the value of the specific keys, if they don't exist, keep en empty String
do your stuff with these values
Map<String, String> map1 = ...;
String v1 = map1.getOrDefault("new", "");
String v2 = map1.getOrDefault("old", "");
Map<String, String> map2 = new HashMap<>();
if(!v1.isEmpty() && !v2.isEmpty() && validateMethod(v1, v2)){
// do your stuff
}
You might put the check for isEmpty in your validateMethod rather than in an if
Try it with this:
yourMap.entrySet().stream()
From this point, you can manage. Stream consists of Entry<Key,Value> so you can check whatever you want to.
I've got list :
ArrayList<String> list = new ArrayList<>();
and map :
Map<String, List<String>> map = new HashMap<>();
I need to compare values of the list and map and return key based on that value
The problem is that I dont know how to synchronize iterations as arraylist has smaller size as each list in map.
Also I tried this method :
public static Object getKeyByValue(Map<String,List<String>> map, String value) {
for (Entry<String, List<String>> entry : map.entrySet()) {
if (Objects.equals(value, entry.getValue())) {
return entry.getKey();
}
}
return null;
}
getKeyByValue(map,list.get(0));
..but this call retuned false even If there is certain value...
Any ideas how get each key for each value?
Thank you very much
You are comparing a List<String> to a String, so it would never return true.
Use List.contains instead, to determine if the String appears in the List :
if (entry.getValue().contains(value)) {
return entry.getKey();
}
String input data is
{phone=333-333-3333, pr_specialist_email=null, sic_code=2391, status=ACTIVE, address1=E.BALL Drive, fax=333-888-3315, naics_code=325220, client_id=862222, bus_name=ENTERPRISES, address2=null, contact=BYRON BUEGE}
Key and values will increase in the array.
I want to get the value for each key ie myString.get("phone") should return 333-333-3333
I am using Java 1.7, is there any tools I can use this to parse the data and get the values.
Some of my input is having values like,
{phone=000000002,Desc="Light PROPERTITES, LCC", Address1="C/O ABC RICHARD",Address2="6508 THOUSAND OAKS BLVD.,",Adress3="SUITE 1120",city=MEMPHIS,state=TN,name=,dob=,DNE=,}
Comma separator doesn't work here
Here is a simple function that will do exacly what you want. It takes your string as an input and returns a Hashmap containing all the keys and values.
private HashMap<String, String> getKeyValueMap(String str) {
// Trim the curly ({}) brackets
str = str.trim().substring(1, str.length() - 1);
// Split all the key-values tuples
String[] split = str.split(",");
String[] keyValue;
HashMap<String, String> map = new HashMap<String, String>();
for (String tuple : split) {
// Seperate the key from the value and put them in the HashMap
keyValue = tuple.split("=");
map.put(keyValue[0].trim(), keyValue[1].trim());
}
// Return the HashMap with all the key-value combinations
return map;
}
Note: This will not work if there's ever a '=' or ',' character in any of the key names or values.
To get any value, all you have to do is:
HashMap<String, String> map = getKeyValueMap(...);
String value = map.get(key);
You can write a simple parser yourself. I'll exclude error checking in this code for brevity.
You should first remove the { and } characters, then split by ', ' and split each resulting string by =. At last add the results into a map.
String input = ...;
Map<String, String> map = new HashMap<>();
input = input.substring(1, input.length() - 1);
String elements[] = input.split(", ");
for(String elem : elements)
{
String values[] = elem.split("=");
map.put(values[0].trim(), values[1].trim());
}
Then, to retrieve a value, just do
String value = map.get("YOURKEY");
You can use "Google Core Libraries for Java API" MapSplitter to do your job.
First remove the curly braces using substring method and use the below code to do your job.
Map<String, String> splitKeyValues = Splitter.on(",")
.omitEmptyStrings()
.trimResults()
.withKeyValueSeparator("=")
.split(stringToSplit);