You need to [disable HTML escaping][1].

    Gson gson = new GsonBuilder().disableHtmlEscaping().create();


  [1]: https://static.javadoc.io/com.google.code.gson/gson/2.8.5/com/google/gson/GsonBuilder.html#disableHtmlEscaping--

the Ampasand symbol was replacing with \u0026 , by using this it got resolved.

**I want to load external images on my page asynchronously using jQuery** and I have tried the following:

    $.ajax({ 
       url: &quot;http://somedomain.com/image.jpg&quot;, 
       timeout:5000,
       success: function() {
    
       },
       error: function(r,x) {
    
       }
    });

But it always returns error, is it even possible to load image like this?

I tried to use [`.load`][1] method and it works but I have no idea how I can set timeout if the image is not available (404). How can I do this?


  [1]: http://api.jquery.com/load/

Asynchronously load images with jQuery

How can you have a function or something that will be executed before your program quits? I have a script that will be constantly running in the background, and I need it to save some data to a file before it exits. Is there a standard way of doing this?

Doing something before program exit

I noticed that [Gson][1] converts the string &quot;&lt;&quot; into an unicode escape sequence in JSON output. Can you avoid this somehow, or do characters like &quot;&lt;&quot; and &quot;&gt;&quot; always have to be escaped in JSON?

Consider this example which prints `{&quot;s&quot;:&quot;\u003c&quot;}`; I&#39;d want simply  `{&quot;s&quot;:&quot;&lt;&quot;}`.

    public static void main(String[] args) {
        Gson gson = new GsonBuilder().create();
        System.out.println(gson.toJson(new Foo()));  
    }

    static class Foo {
        String s = &quot;&lt;&quot;;
    }

Context: the piece of JSON I&#39;m creating has nothing to do with HTML pages or even JavaScript; it&#39;s just used to pass certain structured information to another piece of software (embedded in a device, written in C).

  [1]: http://code.google.com/p/google-gson/

Can you avoid Gson converting &quot;&lt;&quot; and &quot;&gt;&quot; into unicode escape sequences?

I noticed that <a href="http://code.google.com/p/google-gson/" target="_blank" rel="noopener noreferrer">Gson</a> converts the string "&#x3C;" into an unicode escape sequence in JSON output. Can you avoid this somehow, or do characters like "&#x3C;" and ">" always have to be escaped in JSON?
Consider this example which prints <code>{"s":"\u003c"}</code>; I'd want simply <code>{"s":"&#x3C;"}</code>.
<pre><code class="hljs language-typescript">public static void main(String[] args) {
 Gson gson = new GsonBuilder().create();
 System.out.println(gson.toJson(new Foo())); 
}

static class Foo {
 String s = "&#x3C;";
}
</code></pre>
Context: the piece of JSON I'm creating has nothing to do with HTML pages or even JavaScript; it's just used to pass certain structured information to another piece of software (embedded in a device, written in C).

I have 

    private EntityManager em;

	public List getAll(DetachedCriteria detachedCriteria)	{

		return detachedCriteria.getExecutableCriteria(&quot;....&quot;).list();
	}
	
How can I retrieve the session if am using entitymanager, or how can I get the result from my detached criteria?


How can I get the session object if I have the entity-manager?

I have a problem with the replaceAll for a multiline string:

    String regex = &quot;\\s*/\\*.*\\*/&quot;;
    String testWorks = &quot; /** this should be replaced **/ just text&quot;;
    String testIllegal = &quot; /** this should be replaced \n **/ just text&quot;;
    
    testWorks.replaceAll(regex, &quot;x&quot;); 
    testIllegal.replaceAll(regex, &quot;x&quot;); 

The above works for testWorks, but not for testIllegal!?
Why is that and how can I overcome this? I need to replace something like a comment /* ... */ that spans multiple lines.

Java regex replaceAll multiline

In a Java `.properties` file we can do single line comments with `#`.  

Is there any way by which we can do multi-line comments?

Can we have multiline comments in a Java properties file?

Suppose we have a `HashMap&lt;String, Integer&gt;` in Java.

How do I update (increment) the integer-value of the string-key for each existence of the string I find?

One could remove and reenter the pair, but overhead would be a concern.  
Another way would be to just put the new pair and the old one would be replaced.

In the latter case, what happens if there is a hashcode collision with a new key I am trying to insert? The correct behavior for a hashtable would be to assign a different place for it, or make a list out of it in the current bucket.

How to update a value, given a key in a hashmap?

How can I restart a Java AWT application? I have a button to which I have attached an event handler. What code should I use to restart the application?

I want to do the same thing that `Application.Restart()` do in a C# application.


How can I restart a Java application?

Are blank characters like spaces, tabs and carriage returns ignored in json strings?

For example, is `{&quot;a&quot;:&quot;b&quot;}` equal to `{&quot;a&quot; : &quot;b&quot;}`?





Are whitespace characters insignificant in JSON?

So according to the [jQuery Ajax docs][1], it serializes data in the form of a query string when sending requests, but setting `processData:false` should allow me to send actual JSON in the body.  Unfortunately I&#39;m having a hard time determining first, if this is happening and 2nd what the object looks like that is being sent to the server.  All I know is that the server is not parsing what I&#39;m sending.

When using [http client][2] to post an object literal `{someKey:&#39;someData&#39;}`, it works. But when using jQuery with `data: {someKey:&#39;someData&#39;}`, it fails.  Unfortunately when I analyze the request in Safari, it says the message payload is `[object Object]` ... great...  and in Firefox the post is blank...

When logging the body content on the Java side it literally gets `[object Object]` so how does one send REAL JSON data??

Has anyone had experience with a Java service serializing JSON data in the request body, with the request sent from jQuery?  

BTW here is the full $.ajax request:

    $.ajax({
    	contentType: &#39;application/json&#39;,
    	data: {
    		&quot;command&quot;: &quot;on&quot;
    	},
    	dataType: &#39;json&#39;,
    	success: function(data){
    		app.log(&quot;device control succeeded&quot;);
    	},
    	error: function(){
    		app.log(&quot;Device control failed&quot;);
    	},
    	processData: false,
    	type: &#39;POST&#39;,
    	url: &#39;/devices/{device_id}/control&#39;
    });

  [1]: http://api.jquery.com/jQuery.ajax/
  [2]: http://ditchnet.org/httpclient/


jQuery posting valid json in request body

My code:

    import simplejson as json

    s = &quot;{&#39;username&#39;:&#39;dfdsfdsf&#39;}&quot; #1
    #s = &#39;{&quot;username&quot;:&quot;dfdsfdsf&quot;}&#39; #2
    j = json.loads(s)

`#1` definition is wrong

`#2` definition is right

I heard that in Python that ***single*** and ***double*** quote can be interchangable. Can anyone explain this to me?

Single vs double quotes in JSON

If I defined an object in JS with:

    var j={&quot;name&quot;:&quot;binchen&quot;};

How can I convert the object to JSON? The output string should be:

    &#39;{&quot;name&quot;:&quot;binchen&quot;}&#39;

Convert JS object to JSON string

Im trying to get a list of line items to a webpage using JSON, which will then be manipulated and sent back to the server by ajax request using the same JSON structure that arrived (except having had a field values changed). 

Receiving data from the server is easy, manipulation even easier! but sending that JSON data back to the server for saving... suicide time! PLEASE can someone help!

**Javascript**

    var lineitems;

    // get data from server
    $.ajax({
        url: &#39;/Controller/GetData/&#39;,
        success: function(data){
            lineitems = data;
        }
    });
    
    // post data to server
    $.ajax({
        url: &#39;/Controller/SaveData/&#39;,
        data: { incoming: lineitems }
    });

**C# - Objects**

    public class LineItem{
        public string reference;
        public int quantity;
        public decimal amount;
    }

**C# - Controller**

    public JsonResult GetData()
    {
        IEnumerable&lt;LineItem&gt; lineItems = ... ; // a whole bunch of line items
        return Json(lineItems);
    }
    
    public JsonResult SaveData(IEnumerable&lt;LineItem&gt; incoming){
        foreach(LineItem item in incoming){
            // save some stuff
        }
        return Json(new { success = true, message = &quot;Some message&quot; });
    }

The data arrives at the server as serialized post data. The automated model binder tries to bind `IEnumerable&lt;LineItem&gt; incoming` and surprisingly gets the resulting `IEnumerable` has the correct number of `LineItems` - it just doesnt populate them with data.

**SOLUTION**

Using answers from a number of sources, primarily `djch` on another stackoverflow post and `BeRecursive` below, I solved my problem using two main methods.

*Server Side* 

The deserialiser below requires reference to `System.Runtime.Serialization` and `using System.Runtime.Serialization.Json`

	private T Deserialise&lt;T&gt;(string json)
	{
	    using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
	    {
	        var serialiser = new DataContractJsonSerializer(typeof(T));
	        return (T)serialiser.ReadObject(ms);
	    }
	}
	
	public void Action(int id, string items){
	    IEnumerable&lt;LineItem&gt; lineitems = Deserialise&lt;IEnumerable&lt;LineItem&gt;&gt;(items);
	    // do whatever needs to be done - create, update, delete etc.
	}

*Client Side*

It uses json.org&#39;s stringify method, available in this dependecy https://github.com/douglascrockford/JSON-js/blob/master/json2.js (which is 2.5kb when minified)

    $.ajax({
        type: &#39;POST&#39;,
        url: &#39;/Controller/Action&#39;,
        data: { &#39;items&#39;: JSON.stringify(lineItems), &#39;id&#39;: documentId }
    });

Posting JSON Data to ASP.NET MVC

I can serialize a `List&lt;Video&gt;` in my servlet on GAE, but I can&#39;t deserialize it.  What am I doing wrong?

This is my class Video in GAE, which is serialized:

```
package legiontube;

import java.util.Date;

import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.IdentityType;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;

@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class Video {
 
    @PrimaryKey
    private String id;
    
    @Persistent
    private String titulo;
    
    @Persistent
    private String descricao;
    
    @Persistent
    private Date date;

    public Video(){};
    
 public Video(String id, String titulo, String descricao, Date date) {
  //super();
  this.id = id;
  this.titulo = titulo;
  this.descricao = descricao;
  this.date = date;
 }

 public String getId() {
  return id;
 }

 public void setId(String id) {
  this.id = id;
 }

 public String getTitulo() {
  return titulo;
 }

 public void setTitulo(String titulo) {
  this.titulo = titulo;
 }

 public String getDescricao() {
  return descricao;
 }

 public void setDescricao(String descricao) {
  this.descricao = descricao;
 }

 public Date getDate() {
  return date;
 }

 public void setDate(Date date) {
  this.date = date;
 }
    
}
```

This is my class Video in my other application, where I try to deserialize:

```
package classes;

import java.util.Date;

public class Video {
 private String id;
 private String titulo;
 private String descricao;
 private Date date;
 
 public Video(String id, String titulo, String descricao, Date date) {
  //super();
  this.id = id;
  this.titulo = titulo;
  this.descricao = descricao;
  this.date = date;
 }
 
 public String getId() {
  return id;
 }
 public void setId(String id) {
  this.id = id;
 }
 public String getTitulo() {
  return titulo;
 }
 public void setTitulo(String titulo) {
  this.titulo = titulo;
 }
 public String getDescricao() {
  return descricao;
 }
 public void setDescricao(String descricao) {
  this.descricao = descricao;
 }
 public Date getDate() {
  return date;
 }
 public void setDate(Date date) {
  this.date = date;
 }
 
}
```

How to deserialize a list using GSON or another JSON library in Java?

How do I create a json Object using Google Gson?
The following code creates a json object which looks like `{&quot;name&quot;:&quot;john&quot;}`

    JsonObject jsonObject = new JsonObject();
    jsonObject.addProperty(&quot;name&quot;, &quot;john&quot;);

How do I create a jSon Object like this one? 

    {&quot;publisher&quot;:{&quot;name&quot;:&quot;john&quot;}}



Creating GSON Object

I&#39;m trying to learn Gson and I&#39;m struggling with field exclusion. Here are my classes

    public class Student {    
      private Long                id;
      private String              firstName        = &quot;Philip&quot;;
      private String              middleName       = &quot;J.&quot;;
      private String              initials         = &quot;P.F&quot;;
      private String              lastName         = &quot;Fry&quot;;
      private Country             country;
      private Country             countryOfBirth;
    }
    
    public class Country {    
      private Long                id;
      private String              name;
      private Object              other;
    }

I can use the GsonBuilder and add an ExclusionStrategy for a field name like `firstName` or `country` but I can&#39;t seem to manage to exclude properties of certain fields like `country.name`.

Using the method `public boolean shouldSkipField(FieldAttributes fa)`, FieldAttributes doesn&#39;t contain enough information to match the field with a filter like `country.name`.

P.S: I want to avoid annotations since I want to improve on this and use RegEx to filter fields out.

**Edit**: I&#39;m trying to see if it&#39;s possible to emulate the behavior of [Struts2 JSON plugin][1]


  [1]: https://cwiki.apache.org/confluence/display/WW/JSON%20Plugin 
using Gson

    &lt;interceptor-ref name=&quot;json&quot;&gt;
      &lt;param name=&quot;enableSMD&quot;&gt;true&lt;/param&gt;
      &lt;param name=&quot;excludeProperties&quot;&gt;
        login.password,
        studentList.*\.sin
      &lt;/param&gt;
    &lt;/interceptor-ref&gt;

**Edit:**
    I reopened the question with the following addition:

I added a second field with the same type to futher clarify this problem. Basically I want to exclude `country.name` but not `countrOfBirth.name`. I also don&#39;t want to exclude Country as a type.
So the types are the same it&#39;s the actual place in the object graph that I want to pinpoint and exclude.

Gson: How to exclude specific fields from Serialization without annotations

Please advice how to convert a `String` to `JsonObject` using `gson` library. 

What I unsuccesfully do: 

    String string = &quot;abcde&quot;;
    Gson gson = new Gson();
    JsonObject json = new JsonObject();
    json = gson.toJson(string); // Can&#39;t convert String to JsonObject

How to convert a String to JsonObject using gson library

I would like to parse data from JSON which is of type `String`.
I am using [Google Gson][1].

I have:

    jsonLine = &quot;
    {
     &quot;data&quot;: {
      &quot;translations&quot;: [
       {
        &quot;translatedText&quot;: &quot;Hello world&quot;
       }
      ]
     }
    }
    &quot;;

and my class is:

    public class JsonParsing{
    
       public void parse(String jsonLine) {
        
          // there I would like to get String &quot;Hello world&quot;
      
       }
    
    }


  [1]: http://code.google.com/p/google-gson/

Content Type	Original Author	Original Content on Stackoverflow
Question	Jonik	View Question on Stackoverflow
Solution 1 - Java	BalusC	View Answer on Stackoverflow
Solution 2 - Java	ROOPA P D	View Answer on Stackoverflow

Can you avoid Gson converting "<" and ">" into unicode escape sequences?

Java Problem Overview

Java Solutions

Solution 1 - Java

Solution 2 - Java

Doing something before program exit

Asynchronously load images with jQuery

Attributions