CODEWITHSUNDEEP
java
olyanren
olyanren

Reputation: 1458

How to convert a Class' all String fields to uppercase

Hi I want to convert a class's all String field values to their uppercase format. How can I do this? Please help.

Example:

public class ConvertStringToUppercase{
    private String field1; //to be converted Uppercase
    private String field2; //to be converted Uppercase
    private String field3; //to be converted Uppercase
    ...... //more fields
}

Upvotes: 1

Views: 9490

Answers (4)

Vaandu
Vaandu

Reputation: 4945

try {
    ConvertStringToUppercase testClass = new ConvertStringToUppercase();
    for (Field field : testClass.getClass().getDeclaredFields()) {
          if (field.getType().equals(String.class)) {
            if (!field.isAccessible()) 
                field.setAccessible(true);
            if (field.get(testClass) != null && ((String) field.get(testClass)).trim() != "") {                          
                field.set(testClass, ((String) field.get(testClass)).toUpperCase());
            }
          }  
    }
} catch (Exception e) {e.printStackTrace();}

Upvotes: 3

JB Nizet
JB Nizet

Reputation: 691973

public class ConvertStringToUppercase{
    private String field1; //to be converted Uppercase
    private String field2; //to be converted Uppercase
    private String field3; //to be converted Uppercase

    public void toUpperCase() {
        this.field1 = this.field1.toUpperCase();
        this.field2 = this.field2.toUpperCase();
        this.field3 = this.field3.toUpperCase();
        // ...
    }
}

Or, if you want immutability:

public class ConvertStringToUppercase{
    private String field1; //to be converted Uppercase
    private String field2; //to be converted Uppercase
    private String field3; //to be converted Uppercase

    public ConvertStringToUppercase toUpperCase() {
        return new ConvertStringToUppercase(this.field1.toUpperCase(),
                                            this.field2.toUpperCase(),
                                            this.field3.toUpperCase(),
                                            // ...);
    }
}

Make sure to check for null if the fields are nullable.

Upvotes: 5

Tudor
Tudor

Reputation: 62459

You can use reflection for a quick and dirty solution:

ConvertStringToUpperCase t = new ConvertStringToUpperCase();
for(Field f: t.getClass().getDeclaredFields()) {            
    if(f.getType().equals(String.class)) {              
        f.setAccessible(true);
        f.set(t, ((String)f.get(t)).toUpperCase());
    }           
}

This is not a nice approach however, since private fields should not be modified this way.

Upvotes: 2

RokL
RokL

Reputation: 2812

You can do it using reflection but it will be ugly and slow. Use ConvertStringToUppercase.class.getDeclaredFields() to get Field objects. Then use field.getType() == String.class to determine when field is of String type.

Then use field.get(this) to get the string, uppercase it, then use field.set(this, upperCaseString) to set the field to the new value.

Upvotes: 2

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