替换字符串中的字段值

Question

Using Google Guava is there String utility to easily replace string field inside like this:

String query = mydb..sp_mySP ${userId}, ${groupId}, ${someOtherField}

Where I can do something like this:

StringUtil.setString(query)
   .setField("userId", "123")
   .setField("groupId", "456")
   .setField("someOtherField", "12-12-12");

Then the resulting String would be:

mydb..sp_mySP 123, 456, 12-12-12

Of course, setting the String field patter like ${<field>} before the operation...

Anyway, this is my approach:

public class StringUtil {
    public class FieldModifier {
        private String s;
        public FieldModifier(String s){
            this.s = s;
        }
        public FieldModifier setField(String fieldName, Object fieldValue){
            String value = String.valueOf(fieldValue);
            s = modifyField(s, fieldName, value);
            return new FieldModifier(s); 
        }
        public String get() {
                return s;
        }
        private String modifyField(String s, String fieldName, String fieldValue){
            String modified = "";
            return modified;
        }
    }
    public FieldModifier parse(String s){
        FieldModifier fm = new FieldModifier(s);
        return fm; 
    }
}

So in this case, I just need to put the actual code in the modifyField function that will modify the string in a straightforward way. Also if there's a way so the parse function be static so I can just do StringUtil.parse(...) without doing new StringUtil().parse(...) which really doesn't look good.

Answer 1

Yes, String.format() .

String s = "Hey %s! Cool %s, right?";
System.out.println(String.format(s, "xybrek", "feature"));

Answer 2

There's no such thing in Guava. You can have a look at SpEL (Spring Expression Language) which can do string templating, or other templating frameworks such as Velocity or Freemarker .

Answer 3

Using Guava? No.

Though an enhancement has recently been requested to support this ( see here ).

Anyway, this is still doable using Apache Commons Lang's StrSubstitutor .