java - servlet 中不允许使用 void 类型

Question

这是我的 java 类:

   public String year, title,detail;
public League(String year,String title,String detail)
{
    this.year=year;
    this.title=title;
    this.detail=detail;
}
public void getTitle()
{
    System.out.println(""+year+""+title+""+detail+"");
}

这是我的 servlet:

     protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    processRequest(request, response);
    //Creats the set of league
    leagueList=new LinkedList();
    leagueList.add(new League("2003","Spring","Soccer League(Spring`03)"));
    leagueList.add(new League("2003","Summer","Summer Soccer Fest"));
    leagueList.add(new League("2003","Fall","Fall Soccer League"));
    leagueList.add(new League("2004","Spring","Summer Soccer Fest"));
    leagueList.add(new League("2004","Summer","Soccer League(Spring`03)"));
    leagueList.add(new League("2004","Fall","Fall Soccer League"));
}

这是我的 processRequest() 方法

    out.println("<ul>");
        Iterator items=leagueList.iterator();
        while(items.hasNext()){
            out.println("<li>"+League.getTitle()+"</li>");
        }
        out.println("</ul>");

错误是:League.getTitle();//不允许使用void类型

Answer 1

该错误非常具有描述性。您将返回一个 void，或者换句话说，getTitle 方法不返回任何内容。 Java 无法将 void(无)的结果连接到 String。

更改方法以成为正确的 getter:

public String getTitle() {
    return title;
}

此外，还为其他字段创建适当的 getter 方法:

//year field should be an int rather than a String
public String getYear() {
    return year;
}

public String getDetail() {
    return detail;
}