【Java开发bug100例】1.java代码实现合并列

List functions = Arrays.stream(split).map(t -> {
    Function function = new Function();
    function.setName(TO_STRING);
    expressionList expressionList = new expressionList();
    //                Column column = new Column(t);
    String columnName = "IF(%s is not null,%s,'')";
    t = String.format(columnName, t, t);
    Column column = new Column(t);
    expressionList.addexpressions(column);
    function.setParameters(expressionList);
    return function;
}).collect(Collectors.toList());