I have a JSON response which has root as an array of 1 or more objects. I want to extract the value of one of the elements within each object.
Here is the JSON sample:
[
{
"od_pair":"7015400:8727100",
"buckets":[
{
"bucket":"C00",
"original":2,
"available":2
},
{
"bucket":"A01",
"original":76,
"available":0
},
{
"bucket":"B01",
"original":672,
"available":480
}
]
},
{
"od_pair":"7015400:8814001",
"buckets":[
{
"bucket":"C00",
"original":2,
"available":2
},
{
"bucket":"A01",
"original":40,
"available":40
},
{
"bucket":"B01",
"original":672,
"available":672
},
{
"bucket":"B03",
"original":632,
"available":632
},
{
"bucket":"B05",
"original":558,
"available":558
}
]
}
]
I want to access the values of od_pair within each object.
I tried referring to the root array as $ but that did not help.
This is the code snippet I have written:
List<Object> LegList = jsonPath.getList("$");
int NoofLegs = LegList.size();
System.out.println("No of legs :" +NoofLegs);
for (int j=0; j<=NoofLegs;j++) {
String OD_Pair = jsonPath.param("j", j).getString("[j].od_pair");
System.out.println("OD Pair: " + OD_Pair);
List<Object> BucketsList = jsonPath.param("j", j).getList("[j].buckets");
int NoOfBuckets = BucketsList.size();
System.out.println("no of Buckets: " + NoOfBuckets);
}
This is the error that I see:
Caused by:
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup
failed:
Script1.groovy: 1: unexpected token: [ # line 1, column 27.
restAssuredJsonRootObject.[j].od_pair
Can someone kindly help me here please?
You were right to start with the $. However, What you get with your particular JSON is List of HashMap<String, Object> where each JSON Object is represented as a single HashMap. Knowing that you can obtain the list of HashMaps like this:
List<HashMap<String, Object>> jsonObjectsInArray = path.getList("$");
The String will be the name of the attribute. The Object will be either String, Integer, JSONObject or JSONArray. The latter isn't exact class names but it's not relevant to you to achieve desired results.
Now, all we have to do is iterate over the HashMap and extract values of od_pair like this:
for (HashMap<String, Object> jsonObject : jsonObjectsInArray) {
System.out.println(jsonObject.get("od_pair"));
}
The output is:
7015400:8727100
7015400:8814001
Hope it helps!
Related
Say I have a JSON request payload like
{
"workflow": {
"approvalStore": {
"sessionInfo": {
"user": "baduser"
},
"guardType": "Transaction"
}
}
}
I get the value of user via
def user = req.get("workflow").get("approvalStore").get("sessionInfo").get("user")
Now, I get a RestResponse approvalList which I store as list and return to caller as return approvalList.json as JSON. All well so far.
Suppose the response (approvalList.json) looks like below JSONArray -
[
{
"objId": "abc2",
"maker": "baduser"
},
{
"objId": "abc1",
"maker": "baduser"
},
{
"objId": "abc4",
"maker": "gooduser"
}
]
Question : How may I filter the approvalList.json so that it doesn't contain entries (objects) that have "maker": "baduser" ? The value passed to maker should essentially be the user variable I got earlier.
Ideal required output -
It's not entirely clear if you always want a single object returned or a list of objects but using collect is going to be the key here:
// given this list
List approvalList = [
[objId: "abc2", maker: "baduser"],
[objId: "abc1", maker: "baduser"],
[objId: "abc4", maker: "gooduser"]
]
// you mentioned you wanted to match a specific user
String user = "baduser"
List filteredList = approvalList.findAll{ it.maker != user}
// wasn't sure if you wanted a single object or a list...
if (filteredList.size() == 1) {
return filteredList[0] as JSON
} else {
return filteredList as JSON
}
Pretty simple. First parse the JSON into an object, then walk through and test.
JSONObject json = JSON.parse(text)
json.each(){ it ->
it.each(){ k,v ->
if(v=='baduser'){
// throw exception or something
}
}
}
Given the following io.vertx.core.json.JsonObject:
{
"111":[
{
"A":"a1",
},
{
"A":"a2",
},
{
"A":"a3",
}
],
"222":[
{
"A":"a10",
},
{
"A":"a20",
},
{
"A":"a30",
}
]
}
As the name of the outer elements which contain arrays (111 and 222) are not known in advance, what is the correct way to access the elements of each array, e.g.
{"A":"a1"}
Once the elements of the array are available as a collection, how can that collection be turned into an rxJava Observable.
Have tried the following:
List list = arrayElements.stream().collect(Collectors.toList());
Observable observable = Observable.fromIterable(list);
However, the issue is that each element in the stream is then represented as a java.util.LinkedHashMap.Entry, e.g. A=a1, whereas what is required is to retain the original Json representation.
Thanks
You can get object fields with JsonObject.fieldNames().
JsonArray is an Iterable<Object> because it may contain different types (objects, strings, ...etc). If you are confident that a JsonArray only contains JsonObject, you could cast the value.
Here's the result combined:
for (String fieldName : jsonObject.fieldNames()) {
JsonArray jsonArray = jsonObject.getJsonArray(fieldName);
Observable<JsonObject> observable = Observable
.fromIterable(jsonArray)
.map(JsonObject.class::cast);
System.out.println("fieldName = " + fieldName);
observable.subscribe(json -> System.out.println("json = " + json));
}
Given JSON structured like this:
{
"name":"Some Guy",
"emails":[
{
"description":"primary",
"status":"UNVERIFIED",
"email":"first#first-email.com"
},
{
"description":"home",
"status":"VERIFIED",
"email":"second#second-email.com"
},
{
"description":"away",
"status":"VERIFIED",
"email":"third#third-email.com"
}
]
}
I would like a JSONPath expression to get the first email with status VERIFIED and if there are none, then just get the first email in the array. So, given the example above, the result would be second#second-email.com. Given this example:
{
"name":"Some Guy",
"emails":[
{
"description":"primary",
"status":"UNVERIFIED",
"email":"first#first-email.com"
},
{
"description":"home",
"status":"UNVERIFIED",
"email":"second#second-email.com"
}
]
}
the result would be first#first-email.com.
Is this possible with a JSONPath expression?
You effectively have 2 JSONPath expressions, where the second one (first email) should be evaluated only if the first one (first verified email) returns nothing, so I don't think you can evaluate them both at the same time, in a single expression.
You can apply them one after the other, though:
public static String getEmail(String json) {
Configuration cf = Configuration.builder().options(Option.SUPPRESS_EXCEPTIONS).build();
DocumentContext ctx = JsonPath.using(cf).parse(json);
List<String> emails = ctx.read("$.emails[?(#.status == 'VERIFIED')].email");
if (!emails.isEmpty()) {
return emails.get(0);
}
return ctx.read("$.emails[0].email");
}
If the email array is empty, ctx.read("$.emails[0].email") will return null instead of throwing an exception, thanks to the option SUPPRESS_EXCEPTIONS.
If you don't know the number of paths in advance:
public static String getEmail(String json, String[] paths) {
Configuration cf = Configuration.builder().options(Option.ALWAYS_RETURN_LIST, Option.SUPPRESS_EXCEPTIONS).build();
DocumentContext ctx = JsonPath.using(cf).parse(json);
for (String path : paths) {
List<String> emails = ctx.read(path);
if (!emails.isEmpty()) {
return emails.get(0);
}
}
return null;
}
The option ALWAYS_RETURN_LIST means the return type is a list, even when you have one or zero results.
This code should work perfectly for you
//Use the json parsing library to extract the data
JsonPath jp = new JsonPath(json);
Map<String, Object> location = jp.get("name.emails[0]");
System.out.println(location);
I'm a little stumped why I can't pull the "Type" field out of my JSON stream to make a decision. It seems like this should be so easy.
I have the following JSON that I have as input:
[
{
"Institution":"ABC",
"Facility":"XYZ",
"Make":"Sunrise",
"Model":"Admission",
"SerialNumber":"",
"Revision":"1",
"Type":"ABC_Admission",
"ArchiveData":"<CSV file contents>"
}
]
In my Java I have a try-catch block with a JsonHolder class that implements Serializable to hold the JSON. Here's the Java I currently have:
try {
// Parse and split the input
JsonHolder data = JsonHolder.getField("text", input);
DataExtractor.LOG.info("JsonHolder data= " + data);
TreeNode node = data.getTreeNode();
DataExtractor.LOG.info("node size= " + node.size());
node = node.path("Type");
JsonNode json = (JsonNode) node;
DataExtractor.LOG.info("json= " + json.asText());
// code to decide what to do based on Type found
if (json.asText().equals("ABC_Admission")) {
// do one thing
} else {
// do something else
}
} catch (IOException iox) {
DataExtractor.LOG.error("Error extracting data", iox);
this.collector.fail(input);
}
When I run my code I get the following output (NOTE: I changed my package name where the class is to just for this output display)
25741 [Thread-91-DataExtractor] INFO <proprietary package name>.DataExtractor - JsonHolder data= [
{
"Institution":"ABC",
"Facility":"XYZ",
"Make":"Sunrise",
"Model":"Admission",
"SerialNumber":"",
"Revision":"1",
"Type":"ABC_Admission",
"ArchiveData":"<CSV file contents>"
}
]
25741 [Thread-91-DataExtractor] INFO <proprietary package name>.DataExtractor - node size= 1
25741 [Thread-91-DataExtractor] INFO <proprietary package name>.DataExtractor - json=
As you can see I don't get anything out. I just want to extract the value of the field "Type", so I was expecting to get the value "ABC_Admission" in this case. I would have thought the node path would separate out just that field from the rest of the JSON tree.
What am I doing wrong?
After consulting with another developer I found out the issue is my JSON is inside an array. So, I need to iterate over that array and then pull out the Type field from the object.
The updated code to resolve this is below:
try {
// Parse and split the input
JsonHolder data = JsonHolder.getField("text", input);
DataExtractor.LOG.info("JsonHolder data= " + data);
TreeNode node = data.getTreeNode();
String type = null;
// if this is an array of objects, iterate through the array
// to get the object, and reference the field we want
if (node.isArray()){
ArrayNode ary = (ArrayNode) node;
for (int i = 0; i < ary.size(); ++i) {
JsonNode obj = ary.get(i);
if (obj.has("Type")) {
type = obj.path("Type").asText();
break;
}
}
}
if (type == null) {
// Do something with failure??
}
DataExtractor.LOG.info("json= " + type);
if (type.equals("ABC_Admission")) {
// do one thing
else {
// do something else
}
} catch (IOException iox) {
DataExtractor.LOG.error("Error extracting data", iox);
this.collector.fail(input);
}
I want to be able to parse a string to an object that I can access using the dot notation e.g. myobject.property, instead of the array notation e.g. myobject['property']. The array notation works fine. Here's what I have so far.
I have some XML:
<level1 name="level1name">
<level2 type="level2Type">
<entry>level2entry</entry>
<entry>level2entry</entry>
</level2>
</level1>
Which converts to the JSON:
{
"level1": {
"name": "level1name",
"level2": {
"type": "level2Type",
"entry": [
"level2entry",
"level2entry"
]
}
}
}
I have the following Dart code:
Object jsonObject = JSON.parse("""{
"level1": {
"name": "level1name",
"level2": {
"type": "level2Type",
"entry": [
"level2entry",
"level2entry"
]
}
}
}
""");
print("my test 1 == ${jsonObject}");
print("my test 2 == ${jsonObject['level1']}");
print("my test 3 == ${jsonObject['level1']['name']}");
which produce the (desired) output:
my test 1 == {level1: {name: level1name, level2: {type: level2Type, entry: [level2entry, level2entry]}}}
my test 2 == {name: level1name, level2: {type: level2Type, entry: [level2entry, level2entry]}}
my test 3 == level1name
But when I try:
print("my test 1 == ${jsonObject.level1}");
I get the following:
Exception: NoSuchMethodException : method not found: 'get:level1'
Receiver: {level1: {name: level1name, level2: {type: level2Type, entry: [level2entry, level2entry]}}}
Arguments: []
Stack Trace: 0. Function: 'Object.noSuchMethod' url: 'bootstrap' line:717 col:3
Ideally, I want an object that I can access using the dot notation and without the compiler giving warning about Object not having property. I tried the following:
class MyJSONObject extends Object{
Level1 _level1;
Level1 get level1() => _level1;
set level1(Level1 s) => _level1 = s;
}
class Level1 {
String _name;
String get name() => _name;
set name(String s) => _name = s;
}
...
MyJSONObject jsonObject = JSON.parse("""{
"level1": {
"name": "level1name",
"level2": {
"type": "level2Type",
"entry": [
"level2entry",
"level2entry"
]
}
}
}
""");
...
print("my test 1 == ${jsonObject.level1.name}");
but instead of giving me 'level1name' as hoped, I get:
Exception: type 'LinkedHashMapImplementation<String, Dynamic>' is not a subtype of type 'MyJSONObject' of 'jsonObject'.
What am I doing wrong here? Is there any way to do what I'm trying? Thanks.
At the moment, JSON.parse only returns Lists (array), Maps, String, num, bool, and null
(api ref).
I suspect that until reflection makes it way into the language, it won't be able to re-construct objects based upon the keys found in json.
You could, however, create a constructor in your MyJsonObject which took a string, called JSON.parse internally, and assigned the various values.
Something like this works in the dart editor:
#import("dart:json");
class Level2 {
var type;
var entry;
}
class Level1 {
var name;
var level2;
}
class MyJSONObject {
Level1 level1;
MyJSONObject(jsonString) {
Map map = JSON.parse(jsonString);
this.level1 = new Level1();
level1.name = map['level1']['name'];
level1.level2 = new Level2();
level1.level2.type = map['level1']['level2']['type'];
//etc...
}
}
main() {
var obj = new MyJSONObject(json);
print(obj.level1.level2.type);
}
A non trivial version would needs some loops and possible recursion if you had deeper nested levels.
Update: I've hacked together a non-trivial version (inspired by the post below), it's up on github (also taking Seth's comments re the constructor):
Chris is completely right. I will only add that the JSON parser could be modified to return a little richer object (something like JsonMap instead of pure Map) that could allow jsonObj.property by implementing noSuchMethod. That would obviously perform worse than jsonObj['property'].