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SpEL expression supports Elvis operator which is a short form of ternary operator.
// Using ternary operator String result = name != null ? name: "unknown"; // Using Elvis Operator result = name?:"unknown";
Following example shows the various use cases.
Example
Let”s update the project created in Spring SpEL – Create Project chapter. We”re adding/updating following files −
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Employee.java − Employee class.
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MainApp.java − Main application to run and test.
Here is the content of Employee.java file −
package com.tutorialspoint; public class Employee { private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } }
Here is the content of MainApp.java file −
package com.tutorialspoint; import java.text.ParseException; import org.springframework.expression.EvaluationContext; import org.springframework.expression.ExpressionParser; import org.springframework.expression.spel.standard.SpelExpressionParser; import org.springframework.expression.spel.support.StandardEvaluationContext; public class MainApp { public static void main(String[] args) throws ParseException { ExpressionParser parser = new SpelExpressionParser(); Employee employee = new Employee(); EvaluationContext employeeContext = new StandardEvaluationContext(employee); // Evaluates to "unknown" String result = parser.parseExpression("name?:''unknown''").getValue(employeeContext, String.class); System.out.println(result); employee.setName("Mahesh"); // Evaluates to "Mahesh" result = parser.parseExpression("name?:''unknown''").getValue(employeeContext, String.class); System.out.println(result); } }
Output
unknown Mahesh
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