Question

我有一个下一个代码jsp文件：

<%--
  Created by IntelliJ IDEA.
  User: __it
  Date: 08.04.2019
  Time: 14:00
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Student Confirmation</title>
</head>
<body>
The stuent is confirmed: ${student.firstName} ${student.lastName} 
<br><br>
Country: ${student.country}
<br><br>
Favourite language: ${student.favLnguage}
<br><br>
Operating system(s):
<ul>
    <c:forEach var="temp" items="${student.operatingSystems}">
    <li>${temp}"</li>
    </c:forEach>
</ul>
</body>
</html>

在第31行，我尝试遍历operatingSystem数组。在学生课堂上，它看起来像：

 private String[] operatingSystems;

当我运行服务器时，在选择operatingSystems之后，我会得到下一个结果：

如您所见，迭代在浏览器中不起作用，但是从思想上讲，我已经拥有了自己的操作系统。我发出声音以确保选择操作系统后不会返回null。

我的选择框：

<p> Operating systems </p>
Linux <form:checkbox path="operatingSystems" value="Linux"/>
Mac OS <form:checkbox path="operatingSystems" value="MacOS"/>
Windows <form:checkbox path="operatingSystems" value="Wimdows OS"/>

更新：为安东尼

我的Pom XML：

 <?xml version="1.0" encoding="UTF-8"?>
   <project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
   http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.spring</groupId>
    <artifactId>SpringgMVC</artifactId>
    <version>1.0-SNAPSHOT</version>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>10</source>
                    <target>10</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.11</version>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.1.4.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.1.4.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.annotation</groupId>
            <artifactId>javax.annotation-api</artifactId>
            <version>LATEST</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.6.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet/jsp-api -->

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->

    </dependencies>

</project>

Answer 1

我在上面的注释中看到错误的输入（我在URL上没有看到 http：// ）。尽管这可能是偶然完成的。无论如何，尝试将其替换为此：

<%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>

对于支持jstl

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

Answer 2

我仍然不能使用<%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>，但是我在jsp文件中使用了迭代。

    Operating system(s):
<table>
<% String[] system = (String[]) request.getAttribute("os");
    for (int i = 0; i < system.length; i++) {
        String os = system[i];
     %>
    <tr>
        <td><%out.print(os);%></td>
    </tr>
    <%}%>
</table>

在控制器类中，我必须创建一个数组，然后setAttribute("array", array); 是的，这是硬代码，但这是我建立的唯一一个决定。

JSP页面中的ChoiceBox迭代

2 个答案: