Parse JSON array into list

Question

What is the quickest way to parse this json array into a list?

[
 ["FundRequest"],
 ["nOS"],
 ["NEX"],
 ["DREP"],
 ["ChromaWay"],
 ["Jura"],
 ["Origo"],
 ["Phantasma"],
 ["NuCypher"],
 ["Oasis Labs"]
]

Its being generated from the following code:

private void getNames(String spreadsheetUrl) {
 JSONObject json = readJsonFromUrl(spreadsheetUrl);
 String result = json.get("values").toString();
 log.debug("Found: {}", result);
}

The output is from the following json response:

{
 "range": "Frontpage!E6:E15",
 "majorDimension": "ROWS",
 "values": [
 [
 "FundRequest"
 ],
 [
 "nOS"
 ],
 [
 "NEX"
 ],
 [
 "DREP"
 ],
 [
 "ChromaWay"
 ],
 [
 "Jura"
 ],
 [
 "Origo"
 ],
 [
 "Phantasma"
 ],
 [
 "NuCypher"
 ],
 [
 "Oasis Labs"
 ]
 ]
}

• Veselin Davidov: is it array of strings or array of arrays?
• methuselah: it might be an array of arrays. im just trying to get extract the string in each case and save it to a list
• Sudhir Ojha: What value are getting in result variable ?
• methuselah: i get: [ ["FundRequest"], ["nOS"], ["NEX"], ["DREP"], ["ChromaWay"], ["Jura"], ["Origo"], ["Phantasma"], ["NuCypher"], ["Oasis Labs"] ]

Answer 1

You could use a library like GSON:

Install it with maven:

<dependency>
 <groupId>com.google.code.gson</groupId>
 <artifactId>gson</artifactId>
 <version>2.2.4</version>
</dependency>

EDIT:

If you're trying to parse this:

{
 "range": "Frontpage!E6:E15",
 "majorDimension": "ROWS",
 "values": [
 [
 "FundRequest"
 ],
 [
 "nOS"
 ],...

as a java object then create a wrapper class for your json entity:

public class Wrapper {
 private String range;
 private String majorDimension;
 private List<?> values;
 /**
 * @return the range
 */
 public String getRange() {
 return range;
 }
 /**
 * @return the values
 */
 public List<?> getValues() {
 return values;
 }
 /**
 * @param values the values to set
 */
 public void setValues(List<?> values) {
 this.values = values;
 }
 /**
 * @return the majorDimension
 */
 public String getMajorDimension() {
 return majorDimension;
 }
 /**
 * @param majorDimension the majorDimension to set
 */
 public void setMajorDimension(String majorDimension) {
 this.majorDimension = majorDimension;
 }
 /**
 * @param range the range to set
 */
 public void setRange(String range) {
 this.range = range;
 }
}

Then using GSON you can parse a Json string into a wrapper object:

Gson gson = new GsonBuilder().create();
Wrapper w = gson.fromJson(jsonString, Wrapper.class);

Check this: http://www.javacreed.com/simple-gson-example/

EDIT:

If you're trying to parse this:

[
 ["FundRequest"],
 ["nOS"],
 ["NEX"],
 ["DREP"],
 ["ChromaWay"],
 ["Jura"],
 ["Origo"],
 ["Phantasma"],
 ["NuCypher"],
 ["Oasis Labs"]
]

As an array of arrays, then using gson you can do:

 List<?> arr = gson.fromJson("[[\"FundRequest\"],[\"nOS\"],...]", List.class);
 System.out.println(arr);

The println shall print: [[FundRequest], [nOS], ...]

The json array of arrays shall be parsed as a list of lists

Hope this helps

• methuselah: Hi I tried this and I get the following error: java.lang.IllegalStateException: Expected a string but was BEGIN_ARRAY at line 1 column 37 path $.values[0]
• Martín Zaragoza: Are you trying to parse this [ ["FundRequest"], ["nOS"], ...` or this: { "range": "Frontpage!E6:E15", "majorDimension": "ROWS", "values": [ FundRequest" ], ... ?