package com.itranswarp.learnjava;import java.util.StringJoiner;/** * Learn Java from https://www.liaoxuefeng.com/ * * @author liaoxuefeng */public class Main {    public static void main(String[] args) {        String[] fields = {"name", "position", "salary"};        String table = "employee";        String select = buildSelectSql(table, fields);        System.out.println(select);        System.out.println("SELECT name, position, salary FROM employee".equals(select) ? "测试成功" : "测试失败");    }    static String buildSelectSql(String table, String[] fields) {        // TODO:请使用StringJoiner构造一个SELECT语句：        StringJoiner sj = new StringJoiner(", ", "SELECT ", " FROM ");        for (String s : fields) {         sj.add(s);        }        return sj.toString()+table;    }