BE THE CODER > Spring > Expression Language

The Spring Expression Language (SpEL) is a simple and powerful expression language which helps to query and manipulate objects at runtime. The following example shows creating a new instance by invoking constructor using new operator.

File Name :	com/bethecoder/tutorials/spring3/tests/spel/ConstructorTest.java
Author :	Sudhakar KV
Email :	[email protected]


package com.bethecoder.tutorials.spring3.tests.spel;



import java.util.Map;



import org.springframework.expression.ExpressionParser;

import org.springframework.expression.spel.standard.SpelExpressionParser;



import com.bethecoder.tutorials.spring3.basic.Employee;



public class ConstructorTest {



  /**

   * @param args

   */

  public static void main(String[] args) {



    ExpressionParser parser = new SpelExpressionParser();

    Employee emp = parser.parseExpression(

      "new com.bethecoder.tutorials.spring3.basic.Employee(1, 'ABC', 9999)"

    ).getValue(Employee.class);

    

    System.out.println(emp);

    

    String value = parser.parseExpression("new String('ABCDEFG')").getValue(String.class);

    System.out.println(value);

    

    Map simpleMap = parser.parseExpression("new java.util.HashMap()").getValue(Map.class);

    System.out.println(simpleMap.getClass());



    int size = parser.parseExpression("new java.util.HashMap().size()").getValue(int.class);

    System.out.println(size);



    boolean isEmpty = parser.parseExpression("new java.util.ArrayList().isEmpty()").getValue(boolean.class);

    System.out.println(isEmpty);

    

  }

}

Constructors