I have a JSON file like this:
{
"Product":
{
"ID": "08-17-96-71-D9-68",
"Licences":
{
"total": 40,
"used": 0,
"remain": 40
}
}
}
I used jackson to convert it to a Java Object and I get all the values (so far, so good).
My problem is that I want to change these values and re-write the JSON file but when I do that, the result is like this:
"{\"Product\":{\"IaD\": \"08-17-96-71-D9-68\",\"Licences\":{\"total\": 40,\"used\": 1,\"remain\": 39}}}"
So when I tried to read it again it gives me an error because it cannot read the first and last character (") and also it reads the \ character.
This is my code:
public class UsingJason {
String theJsonString = "";
ObjectMapper mapper = new ObjectMapper();
public class Product{
Licences lic;
public class Licences{
int total;
int used;
int remain;
}
}
public void readJson(){
if(new File("asset/testJson.json").exists()){
theJsonString = "";
try {
BufferedReader in = new BufferedReader(new FileReader("asset/testJson.json"));
String line;
while ((line = in.readLine()) != null){
theJsonString += line;
}
in.close();
} catch (IOException e1) {
e1.printStackTrace();
}
System.out.println("JSON String: "+ theJsonString);
}else{
System.out.println("NO FILE FOUND");
}
JsonNode rootNode = null;
try {
rootNode = mapper.readValue(theJsonString, JsonNode.class);
} catch (JsonParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (JsonMappingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
JsonNode totalNode = rootNode.get("Product").get("Licences").get("total");
JsonNode usedNode = rootNode.get("Product").get("Licences").get("used");
JsonNode remainNode = rootNode.get("Product").get("Licences").get("remain");
JsonNode idStringNode = rootNode.get("Product").get("ID");
// Parse it into a Java object.
try {
int totalObject = mapper.readValue(totalNode, Integer.class);
System.out.println("INTEGER? HAS TO BE... 40: "+totalObject);
String idString = mapper.readValue(idStringNode, String.class);
System.out.println("String? Has to be 08-17-96-71-D9-68: "+idString + " True? "
+ idString.equals("08-17-96-71-D9-68") );
int usedObject = mapper.readValue(usedNode, int.class);
int remainObject = mapper.readValue(remainNode, int.class);
System.out.println("Going to rest 1");
usedObject ++;
remainObject = totalObject - usedObject;
String toJackson = "{\"Product\":{\"I\\D\": \"08-17-96-71-D9-68\",\"Licences\":{\"total\": "+totalObject+",\"used\": "+usedObject+",\"remain\": "+remainObject+"}}}";
System.out.println("String created: " +toJackson);
// THIS toJackson String returns the string without \ and without the "
// IT PRINT THIS: {"Product":{"ID": "08-17-96-71-D9-68","Licences":{"total": 40,"used": 1,"remain": 39}}}
// EXACTLY WHAT I WANT TO Write in the Json file but it writes the \ ..
mapper.writeValue(new File("asset/testJson.json"), toJackson);
} catch (JsonParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JsonMappingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Can anyone tell me what I am doing wrong?
In your code here:
mapper.writeValue(new File("asset/testJson.json"), toJackson);
You are serializing not an object, but the string to the file. I suppose this is the reason why it gets escaped, like any string.
The input value should be an object with your structure.
Something like this:
// Initialize an object
Product myProduct = new Product();
myProduct.lic = new Procuct.Licences();
myProduct.lic.total = totalObject;
myProduct.lic.used = usedObject;
myProduct.lic.remain = remainObject;
// Serialize the object into JSON
mapper.writeValue(new File("asset/testJson.json"), myProduct);
Related
I have created a java gui which takes values from the user send it to python file for processing and then displays the output from the python file onto the java gui. This is working perfectly on eclipse but when i exported it into a jar file the output is not displayed. I've seen a bunch of other questions like this but they do not give a solution that would help me.
This is how i connect my python script to java.
public void connection(String name)
{
ProcessBuilder pb= new ProcessBuilder("python","recomold.py","--movie_name",name);
///System.out.println("running file");
Process process = null;
try {
process = pb.start();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
int err = 0;
try {
err = process.waitFor();
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// System.out.println("any errors?"+(err==0 ? "no" : "yes"));
/* try {
System.out.println("python output "+ output(process.getInputStream()));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
try {
matches.setText(output(process.getInputStream()));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private String output(InputStream inputStream) throws IOException {
StringBuilder sb = new StringBuilder();
BufferedReader br = null;
try{
br= new BufferedReader(new InputStreamReader(inputStream));
String line = null;
while((line=br.readLine())!=null)
{
sb.append(line+"\n");
//descp.setText("<html><br/><html>");
//sb.append("\n");
}
}
finally
{
br.close();
}
return sb.toString();
}
I am creating an application that makes calls to the Hitbox API. I am trying to get the game name (listed as category_name from a list.
Thus far, I have managed to get the game name one time during the programs running stage, however when I change where to get the game name from, the program doesn't do anything. I am at a loss as to what could cause it not to send another request to the server.
public void apiConnect(){
String channel = text.getText();
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://api.hitbox.tv/media/live/" + channel);
HttpResponse response = null;
try {
response = client.execute(request);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// Get the response
BufferedReader rd = null;
try {
rd = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));
} catch (UnsupportedOperationException | IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String line = "";
try {
while ((line = rd.readLine()) != null) {
hitbox.append(line);
}
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
FileUtils.writeStringToFile(new File("hitbox.json"), hitbox.getText());
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String game = null;
FileInputStream fileHitbox = null;
try {
fileHitbox = new FileInputStream(new File("hitbox.json"));
} catch (FileNotFoundException e2) {
// TODO Auto-generated catch block
e2.printStackTrace();
}
String strHitbox = null;
try {
strHitbox = IOUtils.toString(fileHitbox, "UTF-8");
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
JSONObject obj = new JSONObject(strHitbox);
JSONArray ar = obj.getJSONArray("livestream");
for (int i = 0; i < ar.length(); i++)
{
game = ar.getJSONObject(i).getString("category_name");
nameOf.setText("Game Name: " + game);
}
File hb = new File("hitbox.json");
if(hb.exists()){
hb.delete();
}
}
The above sample is the defined function, and the Get Game Name button code is below:
btnGetGameName.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
apiConnect();
}
});
Could anyone suggest what is causing it to not work after the first request, and if possible suggest a solution?
EDIT: I have found the issue. The reading of the data from the API is appended to the hitbox variable. I have thus added a snippet that clears what "hitbox" variable has when the button is pressed, thus meaning the code works without issues.
Try to consume your response after your read it to release the resource :
rd = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));
response.getEntity().consumeContent();
//Or if you have EntityUtils
EntityUtils.consume(response.getEntity());
source
I'm trying to parse json (steam webchat) which looks like that (I've changed response cause I don't wanna show the data):
/**/({
"pollid": 00,
"messages": [
{
"type": "personastate",
"timestamp": 0000000000,
"utc_timestamp": 000000000,
"steamid_from": "000000000000",
"status_flags": 0000000,
"persona_state": 0,
"persona_name": "asd"
}
]
,
"messagelast": 00,
"timestamp": 0000000000,
"utc_timestamp": 000000000000,
"messagebase": 00,
"sectimeout": 0,
"error": "OK"
})
And my parsing class looks like that:
package jsonRequest;
import java.io.IOException;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
public class NewMessageJson {
public Integer poollid;
private String lastMessageId;
private String error;
private String messageBase;
public NewMessageJson(String response) {
response = response.substring(response.indexOf("{"),
response.indexOf("}") + 1); // cut off comment block
JsonFactory factory = new JsonFactory();
JsonParser jp = null;
try {
jp = factory.createJsonParser(response);
} catch (JsonParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
if (jp.nextToken() != JsonToken.START_OBJECT) {
throw new IOException("Server didn't return any data");
}
while (jp.nextToken() != JsonToken.END_OBJECT) {
String fieldName = jp.getCurrentName();
jp.nextToken();
if (fieldName.equals("messagelast")) {
setLastMessageId(jp.getText());
} else if (fieldName.equals("pollid")) {
setPoollid(jp.getIntValue());
} else if (fieldName.equals("messagebase")) {
setMessageBase(jp.getText());
} else if (fieldName.equals("error")) {
setError(jp.getText());
}
}
jp.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NullPointerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
jp.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public Integer getPoollid() {
return poollid;
}
public void setPoollid(Integer poollid) {
this.poollid = poollid;
}
public String getLastMessageId() {
return lastMessageId;
}
public void setLastMessageId(String lastMessageId) {
this.lastMessageId = lastMessageId;
}
public String getError() {
return error;
}
public void setError(String error) {
this.error = error;
}
public String getMessageBase() {
return messageBase;
}
public void setMessageBase(String messageBase) {
this.messageBase = messageBase;
}
}
And when it comes to the line
if (fieldName.equals("messagelast")) {
It crashes and returns NPE.
I have 3 other classes looking exactly like this one and everything works perfectly.
I am pretty sure the reason you are getting the NPE is because you initially instantiate JsonParser jp as null. You assign it to factory.createJsonParser(response) in your try block but do not deal with the error in any way besides printing the stack trace. If there was an error executing factory.createJsonParser(response), you need to make sure nothing else runs.
I would suggest changing your code to this:
...
JsonFactory factory = new JsonFactory();
JsonParser jp = null;
try {
jp = factory.createJsonParser(response);
} catch (JsonParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
System.out.println("There was an error while setting jp to factory.createJsonParser(response). Error message is: " + e1.getMessage());
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
System.out.println("There was an error while setting jp to factory.createJsonParser(response). Error message is: " + e1.getMessage());
}
if(jp != null) {
try {
if (jp.nextToken() != JsonToken.START_OBJECT) {
throw new IOException("Server didn't return any data");
}
while (jp.nextToken() != JsonToken.END_OBJECT) {
String fieldName = jp.getCurrentName();
jp.nextToken();
if (fieldName.equals("messagelast")) {
setLastMessageId(jp.getText());
} else if (fieldName.equals("pollid")) {
setPoollid(jp.getIntValue());
} else if (fieldName.equals("messagebase")) {
setMessageBase(jp.getText());
} else if (fieldName.equals("error")) {
setError(jp.getText());
}
}
jp.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NullPointerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
jp.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
...
This way, you can avoid all NPEs!
EDIT: You should also implement what peeskillet suggested
I have an string which I am attempting to extract values from, for convenience I thought that converting the string to a Document and then parsing the xml would be the best way to do this but I am running into all sorts of problems! The string looks like:
<Messagexxx>
<Unit>
<contact>0</contact>
<text>Test Content</text>
<date>09-Sep-14 13:56</date>
<subject>Test Title</subject>
</Unit>
</Messagexxx>
Can someone point me in the correct way to achieve my goal of reading the values from the tags .
I have attempted using the following snippet but I all the values in the array are
null! Document xml = null; Node T = null; try { xml = stringToDom(message); T = xml.getLastChild(); } catch (SAXException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ParserConfigurationException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } if(xml.getFirstChild() != null){ }
When you write your string to a text file, you can first parse it:
private Document parse(String filename){
Document doc = null;
try {
DOMParser parser = new DOMParser();
parser.parse(filename);
doc = parser.getDocument();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return doc;
}
and then you read all text elements out of this document:
public void extract (Document doc){
Node root = doc.getDocumentElement();
for (int i = 0; i< root .getChildNodes().getLength(); i++){
Node child = root.getChildNodes().item(i);
System.out.println(child.getTextContent());
}
}
Use JAXB lib : https://jaxb.java.net/
Create your model from your XML and to read :
JAXBContext jaxbContext = JAXBContext.newInstance(YourModel.class);
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
StringReader reader = new StringReader("xml string here");
YourModel yourModel= (Person) unmarshaller.unmarshal(reader);
After your can use the object "YourModel" to read your value.
This is a very simple way to get node values when you know the node names, and they don't repeat:
String getXmlNodeValue(String xmlString, String nodeName){
int start = xmlString.indexOf("<"+nodeName+">") + nodeName.length() + 2;
int end = xmlString.indexOf("</"+nodeName+">");
return xmlString.substring(start, end);
}
I am trying to develop a plugin, which from a java file generate test and tables classes... when I select a Java source, I will be able to have an option "generate class test", the problem that I am recupering the Java file as ICompliationUnit, then I have a method that xtract methods of an object, that's why; I want to parse the IComplilationUnit to an instance of the class which represents, I tried to use Class.forName but it doesn't work , that's the code:
private void write(String dir, ICompilationUnit cu) throws JavaModelException
{
try
{
cu.getCorrespondingResource().getName();
System.out.println("0000000000000" + cu.getJavaProject().getProject().toString());
}
catch (JavaModelException e1)
{
// TODO Auto-generated catch block
e1.printStackTrace();
}
String test = cu.getCorrespondingResource().getName();
IPackageDeclaration[] test1 = cu.getPackageDeclarations();
// Need
String[] name = test.split("\\.");
String contentFile = dir + "\\" + name[0] + "content.txt";
GenerateFitnessTable inst = new GenerateFitnessTable();
try
{
String pack = test1[0].toString().substring(7, test1[0].toString().indexOf("[") - 1) + "." + name[0];
#SuppressWarnings("rawtypes")
Class classe = Class.forName(cu.getJavaProject().getProject().toString()
.substring(cu.getJavaProject().getProject().toString().indexOf("/"), cu.getJavaProject().getProject().toString().length())
+ pack);
try
{
classe.newInstance();
}
catch (InstantiationException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IllegalAccessException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
catch (ClassNotFoundException e1)
{
System.out.print("****************************la classe n'existe pas");
}
try
{
inst.generateContent(cu, contentFile);
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
this the right way ;)) , i found it :
// nouveau region
region = JavaCore.newRegion();
// ajout de la classe selectionné a cette region
region.add(cu);
if (JavaCore.getGeneratedResources(region, true).length == 0)
{
// bug
}
// recuperer l'url de .class
String url = "file:" + JavaCore.getGeneratedResources(region, true)[0].getLocation().makeAbsolute();
URL myUrl = new URL(url);
URLConnection connection = myUrl.openConnection();
InputStream input = connection.getInputStream();
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int data = input.read();
while (data != -1)
{
buffer.write(data);
data = input.read();
}
input.close();
byte[] classData = buffer.toByteArray();
clas = defineClass(pack.substring(1, pack.length()), classData, 0, classData.length);