CODEWITHSUNDEEP
javadata-binding
vivek
vivek

Reputation: 4919

How to bind a string to object in java

I have a string in this format(response from EBS Payment Gateway)

key1=value1&key2=value2&key3=value3

How to bind to this class object without using split method?

public class MyClass {

    private String key1;
    private String key2;
    private String key3;
    // getter and setter methods
    ...
}

Upvotes: 8

Views: 5494

Answers (7)

Steve P.
Steve P.

Reputation: 14699

String template = "key1=value1&key2=value2&key3=value3";
String pattern = "&?([^&]+)="; 

Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(template);

while (m.find()) 
{
    System.out.println(m.group(1)); //prints capture group number 1
}

Output:

   key1
   key2  
   key3

Of course, this can be shortened to:

Matcher m = Pattern.compile("&?([^&]+)=").matcher("key1=value1&key2=value2&key3=value3");

while (m.find()) 
{
    System.out.println(m.group(1)); //prints capture group number 1
}

Breakdown:

"&?([^&]+)=";

&?: says 0 or 1 &
[^&]+ matches 1 or more characters not equal to &
([^&]+) captures the above characters (allows you to extract them)
&?([^&]+)= captures the above characters such that they begin with 0 or 1 & and end with =

NB: Even though we did not exclude = in [^&], this expression works because if it could match anything with an = sign in it, that string would also have an '&' in it, so [^&=] is unnecessary.

Upvotes: 3

Nguyen
Nguyen

Reputation: 1

You can use java reflection :

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class MyClass {

  private String key1;
  private String key2;
  private String key3;

  public void setKey1(String key1) {
    this.key1 = key1;
  }

  public void setKey2(String key2) {
    this.key2 = key2;
  }

  public void setKey3(String key3) {
    this.key3 = key3;
  }

  public void setKey(String input) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException {
    String[] strings = input.split("&");
    String methodName = null;
    Method setter = null;
    for(String keyValue : strings) {
      String[] keyValuePair = keyValue.split("=");
      methodName = toSetterMethod(keyValuePair[0]);
      setter = getMethod(methodName);
      if (setter != null) {
        setter.setAccessible(true);
        setter.invoke(this, keyValuePair[1]);
      }
    }
  }

  private Method getMethod(String methodName) {
    try {
      Method[] methods = MyClass.class.getMethods();
      for (Method method : methods) {
        if (method.getName().equals(methodName)) {
          return method;
        }
      }
    } catch (SecurityException e) {
    }
    return null;

  }

  private String toSetterMethod(String property) {
    String setter = "set";
    setter += property.substring(0, 1).toUpperCase() + property.substring(1);
    return setter;
  }
  public static void main(String[] args) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException {
    String input = "key1=value1&key2=value2&key3=value3";
    MyClass myClass = new MyClass();
    myClass.setKey(input);

    System.out.println(myClass.key1);
    System.out.println(myClass.key2);
    System.out.println(myClass.key3);


  }

}

Upvotes: 0

jlordo
jlordo

Reputation: 37813

With Guava you can do this:

String str = "key1=value1&key2=value2&key3=value3";
Map<String, String> map = Splitter.on('&').withKeyValueSeparator("=").split(str);

and than you can do with the keys and values whatever you want. E.g.

mc.setKey1(map.get("key1")); // will set key1 to value1

Upvotes: 1

vikrant singh
vikrant singh

Reputation: 2111

Try using beanutils and map

String[] keys = "key1=value1&key2=value2&key3=value3".split("&");
HashMap keyMap = new HashMap();
for(String key:keys){
String[] pair = key.split("=");
keyMap.put(pair[0],pair[1]);
}
MyClass  myCls=new MyClass();
BeanUtils.populate(myCls,keyMap);

Upvotes: 1

user2120239
user2120239

Reputation: 135

This can be done by using the split element in java Store your string in variable and call the split methord in java.

string = "key1=value1&key2=value2&key3=value3";
String[] keys = string.split("&");

IN the next step you can perform a split on each of the elements of the the array keys using the '=' character.

Ref : How to split a string in Java

Upvotes: 0

W A K A L E Y
W A K A L E Y

Reputation: 867

Try following

public class MyClass {

    private String key1;
    private String key2;
    private String key2;

    public MyClass(String k1,String k2,String k3)
    {
        Key1 = k1;
        Key2 = k2;
        Key3 = k3;
    }
// getter and setter methods
...
}

And while creating object of class

String response = "key1=value1&key2=value2&key3=value3";
String[] keys = response.split("&");
MyClass m = new MyClass(keys[0].split("=")[1],keys[1].split("=")[1],keys[2].split("=")[1])

Upvotes: 6

JREN
JREN

Reputation: 3630

Split your string into pieces and then set them using your setters.

String str = "key1=value1&key2=value2&key3=value3";
String[] split = str.split("&");

MyClass obj = new MyClass();

obj.setKey1(split[0].split("=")[1]);
obj.setKey2(split[1].split("=")[1]);
obj.setKey3(split[2].split("=")[1]);

The first split, splits the string at the & symbol.

key1=value1 [0]

key2=value2 [1]

key3=value [2]

After that, you split each of those on the = symbol

key1 [0][0]

value1 [0][1]

key2 [1][0]

value2 [1][1]

key3 [2][0]

value3 [2][1]

So as in the first code block, you have split[0].split("=")[1] which is [0][1] in the explanation below. That's value1

It's quick & dirty but it works perfectly fine :)

Upvotes: 2

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