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java - 将对象数组从 servlet 发送到 JSP

转载 作者:搜寻专家 更新时间:2023-11-01 01:06:50 25 4
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我想根据请求将我自己的对象数组发送到 JSP 页面。

在 servlet 的这部分代码中,我将获取我的数据,将其放在对象数组中,并将它们设置为请求。

     if (request.getParameter("todo").equals("show_article_list")) {
try {
Article[] articles = this.getArticleList();

request.setAttribute("articles", articles);
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("article/article_list.jsp");
dispatcher.forward(request, response);
} catch (Exception e) {
}
}

public Article[] getArticleList() throws Exception {
db data = new db();
Connection con = data.OpenConnection();

PreparedStatement statement = con.prepareStatement("SELECT * FROM `article`");
ResultSet result = statement.executeQuery();


int size = 0;
if (result != null)
{
if (result.last()) {
size = result.getRow();
result.beforeFirst();
}
}

Article[] articles = new Article[size];
int i = 0;
while(result.next()){
articles[i] = new Article (
result.getInt(1),
result.getString(2),
result.getString(3),
result.getString(4));
i++;
}

return articles;
}

这是我的课:

public class Article {
public Integer getId(){return id;}

public String getTitle(){return title;}
public void setTitle(String title){this.title = title;}

public String getText(){return text;}
public void set(String text){this.text = text;}

public String getDescription(){return description;}
public void setDescription(String description){this.description= description;}

private Integer id;
private String title;
private String text;
private String description;

public Article(Integer Id, String Title, String Text, String Description)
{
id = Id;
title = Title;
text = Text;
description = Description;
}
}

在我的 JSP 页面上,我想使用 request.getAttribute("articles"); 循环这样的对象数组我该怎么做?

我必须使用 <jsp:useBean/>或者是其他东西?我试过这样做:

Article[] articles = request.getAttribute("articles");

但是我有一个错误:Article cannot be resolved to a type

我做错了什么?

最佳答案

您应该通过使用 JSTL 来避免使用 scriptlet。请通过以下示例:

POJO 的例子类:

public class Article {
private int id;
private String title;

public Article(int id, String title) {
this.id = id;
this.title = title;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

}

Servlet 示例:

public class TestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Article[] articles =
new Article[] {new Article(1, "Article one"), new Article(2, "Article two")};
request.setAttribute("articles", articles);

RequestDispatcher dispatcher = request.getRequestDispatcher("/index.jsp");
dispatcher.forward(request, response);
}

}

JSP 页面示例:

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:forEach items="${articles}" var="article">
<c:out value="${article.id} ${article.title}"/><br />
</c:forEach>
</body>
</html>

结果 HTML:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

1 Article one<br />

2 Article two<br />

</body>
</html>

希望这个例子能帮到你。

关于java - 将对象数组从 servlet 发送到 JSP,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/9360223/

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