Java 用jsp打印数组
我有一个问题:我会打印一个数组。它是数据库中的元素。使用eclipse,我定义了这个类:Java 用jsp打印数组,java,eclipse,jsp,Java,Eclipse,Jsp,我有一个问题:我会打印一个数组。它是数据库中的元素。使用eclipse,我定义了这个类: package provaprovincie; public class Provincie { public String nome = ""; public String sigla = ""; public Provincie (String nome, String sigla) { this.nome =nome; this.sigla =sigla; } }
package provaprovincie;
public class Provincie {
public String nome = "";
public String sigla = "";
public Provincie (String nome, String sigla)
{
this.nome =nome;
this.sigla =sigla;
}
}
通过这种方式,我从数据库中捕获值:
package provaprovincie;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
public class DBQuery {
public static ArrayList<Provincie> DB_Select_Provincie()
{
ArrayList<Provincie> arrpr = new ArrayList<Provincie>();
try
{
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://" + "127.0.0.1" + "/" + "test" + "?" +
"user=" + "root" + "&password=" + "");
PreparedStatement pstmt = con.prepareStatement("SELECT * FROM provincie");
ResultSet rs = pstmt.executeQuery();
while (rs.next()){
String nome = rs.getString("nome");
String sigla = rs.getString("sigla");
Provincie p = new Provincie (nome, sigla);
arrpr.add(p);
}
con.close();
}
catch (Exception e) {
System.out.println("Errore con DB o Query errata");
e.printStackTrace();
}
return arrpr;
}
}
package provaprovincie;
导入java.sql.Connection;
导入java.sql.DriverManager;
导入java.sql.PreparedStatement;
导入java.sql.ResultSet;
导入java.util.ArrayList;
公共类DBQuery{
公共静态阵列列表DB\u Select\u Provincie()
{
ArrayList arrpr=新的ArrayList();
尝试
{
Class.forName(“com.mysql.jdbc.Driver”);
Connection con=DriverManager.getConnection(“jdbc:mysql://“+”127.0.0.1“+”/“+”测试“+”?”+
“user=“+”root“+”&password=“+”);
PreparedStatement pstmt=con.prepareStatement(“从provincie中选择*);
结果集rs=pstmt.executeQuery();
while(rs.next()){
字符串nome=rs.getString(“nome”);
String sigla=rs.getString(“sigla”);
Provincie p=新Provincie(nome,sigla);
arrpr.add(p);
}
con.close();
}
捕获(例外e){
System.out.println(“错误控制数据库o查询勘误表”);
e、 printStackTrace();
}
返回arrpr;
}
}
在“.jsp”页中,我写道:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ page import="provaprovincie.*" %>
<%@ page import="java.util.ArrayList" %>
<!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=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%
ArrayList<Provincie> prov = DBQuery.DB_Select_Provincie();
for (int i = 0; i < prov.size(); i++)
{
out.print("ciao: " +prov.get(i).nome + "," +prov.get(i).sigla+".");
}
%>
</body>
</html>
在此处插入标题
通过这种方式,eclipse不会打印任何东西…请帮助我…您是否已设置好调试它?soory ma我是一名初学者,我不理解调试编写的内容…您所说的eclipse不会打印任何东西是什么意思?您是否配置了ApacheTomcat(或任何其他web服务器)。您是否在生成项目后启动该服务器?您是否使用url栏中的localhost:8080在web浏览器上打开此页面?我有ApacheTomcat和eclipse的最佳配置,因为我与其他项目一起工作,它们运行正常。我在eclipse上打开页面…您的数据库连接可能有问题。你检查过堆栈跟踪了吗。如果是,请将其附在此处。提供额外信息会增加获得解决方案的机会吗?