java - 在 servlet 中显示结果的问题（对于数组，java）

Question

我在 servlet 中遇到了一些麻烦。我从 Apache Tomcat 运行它。所以我在启动时运行它，我有一个控制台，一般来说一切都是标准的，但这里是代码：

import java.io.*;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.*;
import javax.servlet.http.*;

public class servletss extends HttpServlet {

    @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {
        res.setContentType("text/html");
        PrintWriter out = res.getWriter();


        File file = new File("C:\\prov");
        String list[] = file.list();


        out.println("<html>");
        out.println("<head>");
        out.println("<title>testservlets</title>");
        out.println("</head>");
        out.println("<body>");
        /*
        * начало вывода
        */

        ArrayList<String> sizel = new ArrayList<String>();
    sizel = pagef();
    int sizelist;
    sizelist = sizel.size();


        int pageint = 1;// номер страницы


    ArrayList<String> sizetris = new ArrayList<String>();

    int startlist = (pageint - 1) * 30;
        int endlist = (sizel.size() >= (startlist + 30)) ? (startlist + 30): sizel.size();

    sizetris.addAll(sizel.subList(startlist, endlist));

    double startdouble = 10.0;// конец показа страниц
        int endint = (int) (pageint * 10);// конечное число пользователя
    double allpage = sizelist / 3;// число страниц всего
        double page = allpage / startdouble;// деление страниц
    double lsc = Math.ceil(page);
        String separator = System.getProperty("line.separator");
        if (endint > lsc * 10) {
            out.println("страниц не найдено");
        } else {
            out.println("<div class=\"pagen\">" + pageint + "</div>");

                        String str = paginate(sizetris, endint * 3);
            out.println("<div class=\"bloctext\">" + str + separator + "</div>");

            out.println("<div class=\"pagen\">" + pageint + "</div>");
        }




        for (int i = 0; i < list.length; i++) {
            out.println("<a href=\"http://localhost:8080/test/servletss?i=" + i + "\" str=\"" + i + "\">" + i + "</a>");

        }
        out.println("</body>");

        out.println("</html>");
    }


    static <T> String paginate(List<T> pages, int pagesPerOut) {
        for (int i = 0; i < pages.size(); i += pagesPerOut) {
            System.out.println(paginate(pages, i, pagesPerOut));
        }
        return "";

    }


    static <T> List<T> paginate(List<T> pages, int start, int count) {
        int end = start + count > pages.size() ? pages.size() : start + count;
        return pages.subList(start, end);

    }
        /*
         * метод для возвращения массива страниц
         */

    static ArrayList<String> pagef() {
        ArrayList<String> page = new ArrayList<String>();
        BufferedReader br = null;
        String s = null;
        File file = new File("C:\\prov");
        String list[] = file.list();

        try {
            for (int i = 0; i < list.length; i++) {
                File fileread = new File("C:\\prov\\" + list[i]);
                br = new BufferedReader(new InputStreamReader(
                        new FileInputStream(fileread), "UTF-8"));
                while ((s = br.readLine()) != null) {
                    page.add(s + "\n");
                }
                br.close();
            }
        } catch (Exception e) {
                    System.out.println(e);
        }

        return page;

    }
}

我开始了它，现在这部分代码：

out.println("<div class=\"bloctext\">" + str + separator + "</div>");

她必须缝 30 针，但是当我运行代码时，我什么都看不到，但是看着控制台我看到了我的 30 针））在控制台 Tomcat））为什么那里的工作结果，而不是页面变成一个servlet？您的代码中还有其他问题，不要看，请告诉我如何解决这个问题？一切都正确，servlet在正确的文件夹中，这里是web.xml代码文件，以防万一：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">


    <servlet>
        <servlet-name>servletss</servlet-name>
        <servlet-class>servletss</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>servletss</servlet-name>
        <url-pattern>/servletss</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

提前感谢您的回答））

UPD

import java.io.*;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.*;
import javax.servlet.http.*;

public class servletss extends HttpServlet {

    @Override
     protected void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {
        res.setContentType("text/html");
        PrintWriter out;

            out = res.getWriter();



        File file = new File("C:\\prov");
        String list[] = file.list();


        out.println("<html>");
        out.println("<head>");
        out.println("<title>testservlets</title>");
        out.println("</head>");
        out.println("<body>");
        /*
        * начало вывода
        */

        ArrayList<String> sizel = new ArrayList<String>();
    sizel = pagef();
    int sizelist;
    sizelist = sizel.size();


        int pageint = 1;// номер страницы


    ArrayList<String> sizetris = new ArrayList<String>();

    int startlist = (pageint - 1) * 30;
        int endlist = (sizel.size() >= (startlist + 30)) ? (startlist + 30): sizel.size();

    sizetris.addAll(sizel.subList(startlist, endlist));

    double startdouble = 10.0;// конец показа страниц
        int endint = (int) (pageint * 10);// конечное число пользователя
    double allpage = sizelist / 3;// число страниц всего
        double page = allpage / startdouble;// деление страниц
    double lsc = Math.ceil(page);
        String separator = System.getProperty("line.separator");
        if (endint > lsc * 10) {
            out.println("страниц не найдено");
        } else {
            out.println("<div class=\"pagen\">" + pageint + "</div>");

                        String str = paginate(sizetris, endint * 3);
            out.println("<div class=\"bloctext\">" + str + separator + "</div>");

            out.println("<div class=\"pagen\">" + pageint + "</div>");
        }




        for (int i = 0; i < list.length; i++) {
            out.println("<a href=\"http://localhost:8080/test/servletss?i=" + i + "\" str=\"" + i + "\">" + i + "</a>");

        }
        out.println("</body>");

        out.println("</html>");
        out.flush();
        out.close();
    }

    static <T> String paginate(List<T> pages, int pagesPerOut) {
        for (int i = 0; i < pages.size(); i += pagesPerOut) {
            System.out.println(paginate(pages, i, pagesPerOut));
        }
        return "";

    }


    static <T> List<T> paginate(List<T> pages, int start, int count) {
        int end = start + count > pages.size() ? pages.size() : start + count;
        return pages.subList(start, end);

    }
        /*
         * метод для возвращения массива страниц
         */

    static ArrayList<String> pagef() {
        ArrayList<String> page = new ArrayList<String>();
        BufferedReader br = null;
        String s = null;
        File file = new File("C:\\prov");
        String list[] = file.list();

        try {
            for (int i = 0; i < list.length; i++) {
                File fileread = new File("C:\\prov\\" + list[i]);
                br = new BufferedReader(new InputStreamReader(
                        new FileInputStream(fileread), "UTF-8"));
                while ((s = br.readLine()) != null) {
                    page.add(s + "\n");
                }
                br.close();
            }
        } catch (Exception e) {
                    System.out.println(e);
        }

        return page;

    }
}

更新 2

<html>
<head>
<title>testservlets</title>
</head>
<body>
<div class="pagen">1</div>
<div class="bloctext">
 //There must be a conclusion, but it in a servlet
</div>
<div class="pagen">1</div>
<a href="http://localhost:8080/test/servletss?i=0" str="0">0</a>
<a href="http://localhost:8080/test/servletss?i=1" str="1">1</a>
<a href="http://localhost:8080/test/servletss?i=2" str="2">2</a>
<a href="http://localhost:8080/test/servletss?i=3" str="3">3</a>
<a href="http://localhost:8080/test/servletss?i=4" str="4">4</a>
<a href="http://localhost:8080/test/servletss?i=5" str="5">5</a>
<a href="http://localhost:8080/test/servletss?i=6" str="6">6</a>
<a href="http://localhost:8080/test/servletss?i=7" str="7">7</a>
<a href="http://localhost:8080/test/servletss?i=8" str="8">8</a>
<a href="http://localhost:8080/test/servletss?i=9" str="9">9</a>
<a href="http://localhost:8080/test/servletss?i=10" str="10">10</a>
<a href="http://localhost:8080/test/servletss?i=11" str="11">11</a>
<a href="http://localhost:8080/test/servletss?i=12" str="12">12</a>
<a href="http://localhost:8080/test/servletss?i=13" str="13">13</a>
<a href="http://localhost:8080/test/servletss?i=14" str="14">14</a>
<a href="http://localhost:8080/test/servletss?i=15" str="15">15</a>
<a href="http://localhost:8080/test/servletss?i=16" str="16">16</a>
<a href="http://localhost:8080/test/servletss?i=17" str="17">17</a>
<a href="http://localhost:8080/test/servletss?i=18" str="18">18</a>
<a href="http://localhost:8080/test/servletss?i=19" str="19">19</a>
<a href="http://localhost:8080/test/servletss?i=20" str="20">20</a>
<a href="http://localhost:8080/test/servletss?i=21" str="21">21</a>
<a href="http://localhost:8080/test/servletss?i=22" str="22">22</a>
<a href="http://localhost:8080/test/servletss?i=23" str="23">23</a>
<a href="http://localhost:8080/test/servletss?i=24" str="24">24</a>
</body>
</html>

score 0 · Accepted Answer

看起来doGet()你没有做out.flush()和out.close()。

PrintWriter是Buffered writer的类型，当您说它out.print()写入buffer而不是实际的stream时。要使缓冲区的内容流向流（在您的情况下是您的流HttpServletResponse），您需要调用out.flush()

编辑：您可以像这样out.println("</html>");（在方法结束时）调用这些方法，doGet()

out.println("</html>");
out.flush();
out.close();

java - 在 servlet 中显示结果的问题（对于数组，java）

1 回答 1

Related

Reference