的Java Web瀏覽器程序的問題

Question

我試圖做出一類這個網頁瀏覽器，但我無法得到它的工作：

import java.io.*; 
import javax.swing.JLabel; 
import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import java.net.URL; 
import javax.swing.JFrame; 
import java.util.*; 

public class WebViewer { 
    public static void main(String[] argv) throws Exception { 
     System.out.println("This program is made to view HTML code."); 
     Scanner input = new Scanner(System.in); 
     System.out.println("Enter webpage URL"); 
     String url = (""); 
     String webpage = input.next(); 
     webpage = new URL(url); 

     BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream())); 
     String str; 

     while ((str = in.readLine()) != null) { 
      System.out.println(str); 
      JLabel textLabel = new JLabel(str); 
     } 
    } 
} 

// NEEDS FIXING 

我最新的錯誤消息是：「不兼容的類型：java.net.URL中不能被轉換爲java.lang.String

任何人有任何建議，所有將不勝感激

Answer 1

你的變量webpage是String類型和你試圖URL類型的對象賦給它：？

String webpage = input.next(); 
    webpage = new URL(url); 

這是不可能的。我甚至不明白爲什麼，因爲之後你沒有使用webpage。

Answer 2

您正在將Url對象傳遞給不正確的String。 使用此：

URL url = new URL("url"); 
url.openStream(); 

Answer 3

import javax.swing.JLabel; 
import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import java.net.URL; 
import javax.swing.JFrame; 
import java.net.URLConnection; 
import java.util.*; 

public class WebViewer { 
    public static void main(String[] argv) throws Exception { 
     System.out.println("This program is made to view HTML code."); 
     Scanner input = new Scanner(System.in); 
     System.out.println("Enter webpage URL"); 
     String url; 
     url = input.next(); 
     URL webpage = new URL("http://" + url); 

     URLConnection is = webpage.openConnection(); 

     BufferedReader in = new BufferedReader(new InputStreamReader(is.getInputStream(), "UTF-8")); 
     String str; 
     StringBuilder a = new StringBuilder(); 

     while ((str = in.readLine()) != null) { 
      a.append(str); 
      JLabel textLabel = new JLabel(str); 
     } 
    } 
} 

該代碼可以解決你的問題，但你必須正確設置的JLabel。