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我在这里有一个问题，我试图根据一个人的年龄计算一个人的月、周、天、小时、分钟和秒数。我正在使用 HTML 表单来获取数据（姓名和年龄）并将其发送到 servlet 以计算上述结果。问题在于，当用户提供 29 岁或以下的年龄时，结果似乎是准确的，但当用户输入 70 或以上这样的大值时，它会给出错误的秒数负值。这是我的servlet代码：

package package1;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Servlet_Post_Example extends HttpServlet
{
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
    {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        String name = "";
        String $age = "";
        try
        {
            name = request.getParameter("name");
            $age = request.getParameter("age");
            int age = Integer.parseInt($age);
            int months = age * 12;
            int weeks = age * 52;
            int days = age * 365;
            int hours = 24 * 365 * age;
            int minutes = 60 * 24 * 365 * age;
            int seconds = 60 * minutes;
            out.println("<html>");
            out.println("   <head>");
            out.println("       <title>Servlet Get Response</title>");
            out.println("   </head>");
            out.println("   <body bgcolor=\"#AAFFAA\">");
            out.println("       <h1>"+name+" you are approximately "+months+" months old, "+weeks+" weeks old, "+days+" days old, "+hours+" hours old, "+minutes+" minutes old and "+seconds+" seconds old!</h1>");
            out.println("       <a href=\"index.html\">Click here</a> to go back to the index page.");
            out.println("   </body>");
            out.println("</html>");
        }
        catch(NumberFormatException xcp)
        {
            out.println("<html>");
            out.println("   <head>");
            out.println("       <title>Servlet Get Response</title>");
            out.println("   </head>");
            out.println("   <body bgcolor=\"#AAAAAA\">");
            out.println("       <h1 style=\"color: red\">There was an error! You must type the a valid integer for your age! You entered "+$age+"</h1>");
            out.println("       <a href=\"index.html\">Click here</a> to go back to the index page.");
            out.println("   </body>");
            out.println("</html>");
            //xcp.printStackTrace(out);
        }
        finally
        {
            out.close();
        }
    }
}

该网站托管在这里。请检查一下谢谢。

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2 回答 2

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这条线可能int minutes = 60 * 24 * 365 * age;会int seconds = 60 * minutes;超过Integer.MAX_VALUE. 将分钟和秒声明为 long：

long minutes = 60L * 24 * 365 * age;// Add L for long
long seconds = 60 * minutes;
于 2013-11-02T15:21:39.667 回答
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您需要将分钟和秒的类型更改为长。然后它应该可以正常工作。由于任何大于 2^31-1 的 int 值都会导致溢出，并且由于此溢出是无声的，因此您得到了负值。

于 2013-11-02T15:22:39.913 回答