>>365 こんなのであってます？
private String str1;
private String str2;

public String getStr1() {
this.str1;
}

public String getStr2() {
this.str2;
}

public void setValue(String fieldName, Object value) throws Exception {
Field f = this.getClass().getField(fieldName);
if (value != null) {
if (value instanceof String) {
f.set(this, ((String)value).trim());
} else {
f.set(this., value);
}
}
}