How to add request body to http Delete method

Http Methods methods:

While consuming web services, many tume we need to call http put, delete, get, post methods. While calling http het and post methods are regularly used and you need minimal configuration, put, delete, etc methods some time confuse developer.

Problem with Http Delete methods:

In case of http delete methods, we cannot send request body if your are using http client. it does not allow to do as there is no methods avaialble.

You will face this problem in case you are developing an application where you web service end point need some data in the delete methods and in clent there are no ways to do that.

Soloutions:

The solution is to extend the http post method and change the method to DELETE while sending data. One of the easiest way I would suggest is as below.

Extend the HttpPost method and change the method to DELETE as below and then create the object of HttpPost rather HttpDelete.

class MyHttpDelete extends HttpPost {

public MyHttpDelete (String url){

       super(url);

}

@Override

 public String getMethod() {

       return "DELETE";

 }

}

object creation will be as below:

MyHttpDelete httpPost = new MyHttpDelete(url);

How to remove java 1.8 from class path and set java 1.7 in windows 10

Windows 10 degrading from java 1.8 to java 1.7

I have been developing a project which is on google app engine and java sdk 1.7. When I upgraded to windows 10 from my windows 7 machine, the by default java verion was jre 1.8 and when ever I have bed executing any task, the version miss matching was happening.

JDK:

 jdk and jre are 2 different thing. The jdk is responsible to compile your java code using javac compailer and generate .class file which contains java byte code which is executed in jvm(java virtual machine)

JRE:

jre is something which execute the class file and guve you the result. any operating system gives you jre not jdk as jre executes most of the internal java codes

How to chge default windows 10 jre version from java 1.8 to 1.7

In windw 10, the C:\Windows\System32 (c:\Windows\SysWOW64 folder if you have x64 system [Win 7 64 bits]) folder contains java.exe, javaw.exe and javaws.exe which is dafault java execution and any call path you will set for the java will not over ride it as these are highest priority in windows.To set you default path to java jre 1.7 you need to delete them. may be you can take a backup in case you want to come back to jre 1.8.then what ever class path jre and jdk is available, it will point to you java version in your machine.

Making Http call from core java - different ways

There are many ways we make http calls to web server in many situation. We application server always receives requests in many forms and send back response in many forms.

Now a days there are a lots of framework, library available to kame http call easy to the web server like Spring, Struts, Ajax, etc.

 But if the requirement is simple and need just a simple and light weight http call to the server, you will not like to use these heavy library which comes will many extra functionality which you dont need. In this case the best way is to use the inbuild hava http functionality to get response data from the web server.

below are few example which will help you to understand batter

Using HttpConnect

conn = (HttpURLConnection) new URL(url).openConnection();
conn.setRequestMethod(method);
conn.setRequestProperty("X-DocuSign-Authentication", httpAuthHeader);
conn.setRequestProperty("Accept", "application/json");
if (method.equalsIgnoreCase("POST")) {
  conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
  conn.setRequestProperty("Content-Length", Integer.toString(body.length()));
            conn.setDoOutput(true);
}


status = conn.getResponseCode(); // triggers the request
if (status != 200) { //// 200 = OK 
    errorParse(conn, status);
    return;
}

InputStream is = conn.getInputStream();

Another way is using HttpPost

  try {
   // 1. create HttpClient
   HttpClient httpclient = new DefaultHttpClient();

   // 2. make POST request to the given URL
   HttpPost httpPost = new HttpPost(authUrl);

   String json = "";

   // 3. build jsonObject
   JSONObject jsonObject = new JSONObject();
   jsonObject.accumulate("phone", "phone");

   // 4. convert JSONObject to JSON to String
   json = jsonObject.toString();

   // 5. set json to StringEntity
   StringEntity se = new StringEntity(json);

   // 6. set httpPost Entity
   httpPost.setEntity(se);

   // 7. Set some headers to inform server about the type of the
   // content
   httpPost.addHeader("Accept", "application/json");
   httpPost.addHeader("Content-Type", "application/x-www-form-urlencoded");

   // 8. Execute
   HttpResponse httpResponse = httpclient.execute(httpPost);

   // 9. receive response as inputStream
   inputStream = httpResponse.getEntity().getContent();
   String response = getResponseBody(inputStream);
   
   System.out.println(response);

  } catch (ClientProtocolException e) {
   System.out.println("ClientProtocolException : " + e.getLocalizedMessage());
  } catch (IOException e) {
   System.out.println("IOException:" + e.getLocalizedMessage());
  } catch (Exception e) {
   System.out.println("Exception:" + e.getLocalizedMessage());
  }

Updating column 1 or column 2 with value of same column value or different column value of same table

Some time we need to change values of columns of same row of a table.

update  table_name set column1 = column2

you can also put some arithmetic calculation and update table as well. the above query will take the value of column2 and will store it in the column1 of the same row of same table.