如何在从Java程序发送邮件时清除异常?
我正在使用EclipseLuna包。我需要从我的Java程序发送一封电子邮件。运行程序时引发异常如何在从Java程序发送邮件时清除异常?,java,eclipse,Java,Eclipse,我正在使用EclipseLuna包。我需要从我的Java程序发送一封电子邮件。运行程序时引发异常 package a1; import java.io.*; import java.net.*; public class a4 { public static void main(String[] args) { try { if (args.length >= 1) System.getProperties().put("mail.host
package a1;
import java.io.*;
import java.net.*;
public class a4 {
public static void main(String[] args) {
try {
if (args.length >= 1) System.getProperties().put("mail.host", args[0]);
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
System.out.print("From: ");
String from = in.readLine();
System.out.print("To: ");
String to = in.readLine();
System.out.print("Subject: ");
String subject = in.readLine();
URL u = new URL("mailto:" + to);
URLConnection c = u.openConnection();
c.setDoInput(false);
c.setDoOutput(true);
System.out.println("Connecting...");
System.out.flush();
c.connect();
PrintWriter out = new PrintWriter(new OutputStreamWriter(c.getOutputStream()));
out.println("From: \"" + from + "\" <" +
System.getProperty("user.name") + "@" +
InetAddress.getLocalHost().getHostName() + ">");
out.println("To: " + to);
out.println("Subject: " + subject);
out.println(); System.out.println("Enter the message. " +
"End with a '.' on a line by itself.");
String line;
for(;;) {
line = in.readLine();
if ((line == null) || line.equals(".")) break;
out.println(line);
}
out.close();
System.out.println("Message sent.");
System.out.flush();
}
catch (Exception e) {
System.err.println(e);
System.err.println("Usage: java SendMail [<mailhost>]");
}
}
}
a1包;
导入java.io.*;
导入java.net。*;
公共a4级{
公共静态void main(字符串[]args){
试试{
如果(args.length>=1)System.getProperties().put(“mail.host”,args[0]);
BufferedReader in=新的BufferedReader(新的InputStreamReader(System.in));
系统输出打印(“从:”);
字符串from=in.readLine();
系统输出打印(“至:”);
字符串to=in.readLine();
系统输出打印(“主题:”);
字符串subject=in.readLine();
URL u=新URL(“邮件收件人:+to”);
URLConnection c=u.openConnection();
c、 setDoInput(假);
c、 设置输出(真);
System.out.println(“连接…”);
System.out.flush();
c、 connect();
PrintWriter out=新的PrintWriter(新的OutputStreamWriter(c.getOutputStream());
println(“From:\”“+From+”\”);
out.println(“To:+To”);
out.println(“主题:+主题”);
out.println();System.out.println(“输入消息”。+
“在一行上以“.”结束。”);
弦线;
对于(;;){
line=in.readLine();
如果((line==null)| line.equals(“.”)中断;
out.println(行);
}
out.close();
System.out.println(“消息已发送”);
System.out.flush();
}
捕获(例外e){
系统错误println(e);
System.err.println(“用法:JavaSendmail[]);
}
}
}
运行此程序时引发异常。我的输出屏幕如下
From: skalyanasundaram1994@gmail.com
To: bharani829@gmail.com
Subject: hai
Connecting...
java.net.UnknownHostException: mailhost
Usage: java SendMail [<mailhost>]
来自:skalyanasundaram1994@gmail.com
致:bharani829@gmail.com
主题:海
连接。。。
java.net.UnknownHostException:mailhost
用法:javasendmail[]
您在命令行上指定的“mailhost”不是服务器的有效DNS名称
您需要指定愿意在端口25上为您的应用程序提供服务的邮件服务器的名称或IP号。从您的输出中,它看起来像是您的
邮件。主机默认为mailhost
,这在您的系统上无法解析。在大多数公司,这类似于smtp.example.com
,但请与您当地的电子邮件管理员联系,查看哪些内容对您的环境有效。这看起来确实是一个未知的例外。您使用的邮件主机是什么?@DanWInetAddress.getLocalHost().getHostName()
您正在尝试从java应用程序发送电子邮件吗?是的,我正在尝试从我的java应用程序发送邮件。。。