サンプル

public class ClassA {
private final StringBuffer stringObject = new StringBuffer("A new String");
private StringBuffer nonConstantString = new StringBuffer("Changing String");

public void method() {
StringBuffer localString;
final StringBuffer localConstantString;
}
}

解決策
代わりに、String を使用して、定数 (final) StringBuffer オブジェクトを宣言してください。

public class ClassA {
private final String stringObject = "A new String";
private StringBuffer nonConstantString = new StringBuffer("Changing String");

public void method() {
StringBuffer localString;
final String localConstantString;
}
}