写一个函数判断字符串中{与}，[与]，(与)匹配，{必须在}前面，[必须在]前面，(必须在)前面，可以嵌套

boolean matchBracket( String str ){Stack stack = new Stack();try{for ( int i = 0; i < str.length(); i++ ){char curChar = str.charAt( i );switch ( curChar ){case ‘[‘:case ‘{‘:case ‘(‘:stack.push( curChar );break;case ‘]’:if ( !stack.pop().equals( ‘[‘ ) ){return false;}break;case ‘}’:if ( !stack.pop().equals( ‘{‘ ) ){return false;}break;case ‘)’:if ( !stack.pop().equals( ‘(‘ ) ){return false;}break;}}} catch ( EmptyStackException e ){return false;}if ( stack.isEmpty() )return true;;}，销售世界上第一号的产品——不是汽车，