示例

public class ClassA {{
public void test () {
String stringObject = "my.test" ;

// to print out the object name "my"
System.out.println( stringObject.substring( 0, stringObject.indexOf('.') ) );
}

}

解决方案
改用 StringTokenizer 来解析字符串。

public class ClassA {{
public void test () {
String stringObject = "my.test" ;

// to print out the object name "my"
StringTokenizer st = new StringTokenizer (stringObject, ".");
System.out.println( st.nextToken() );
}

}