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

错误非常具有描述性。您返回void或换句话说，getTitle方法不返回任何内容。 Java无法将void（无）的结果连接到String。

将方法更改为适当的吸气剂：

public String getTitle() {
    return title;
}

此外，还为其他字段创建正确的getter方法：

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

public String getDetail() {
    return detail;
}

Answer 2

getTitle()不返回任何内容（void），您尝试将其添加到字符串中。

使用此：

public String getTitle()
{
    return year + title + detail;
}

servlet中不允许使用void类型

2 个答案: