为什么我得到一个“无法找到符号”错误

Question

我正在尝试做一个从URL获取源代码的类。我不明白为什么我收到了这条线“找不到符号错误”：

catch (MalformaedURLException e)

如果有人能解释什么是错，这将是美好的...谢谢

这是我整个的代码：

import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import java.net.URL; 
import java.net.URLConnection; 
import java.net.MalformedURLException; 

public class SourceCode 
{ 
private String source; 
public SourceCode(String url) 
{ 
    try 
    { 
     URL page = new URL(url); 
     this.source = getSource(page); 
    } 
    catch (MalformedURLException e) 
    { 
     e.printStackTrace(); 
    } 
} 

public String getSource(URL url) throws Exception 
{ 

     URLConnection spoof = url.openConnection(); 
     BufferedReader in = new BufferedReader(new InputStreamReader(spoof.getInputStream())); 
     String strLine = ""; 

     spoof.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0; H010818)"); 


     while ((strLine = in.readLine()) != null) 
     { 
      strLine = strLine + "\n"; 
     } 
     return strLine; 
} 

}

Answer 1

有多个问题与此代码。

1. 你缺少进口的java.net.MalformedURLException
2. getSource()不返回任何东西，你需要从方法返回一个字符串。
3. 你开始从源头上阅读
4. 你的构造函数被忽略扔出来

5. 的异常，而不是有没有消气源

   进口java.io.BufferedReader中后设置spoof.setRequestProperty; import java.io.IOException; import java.io.InputStreamReader; import java.net.URL; import java.net.URLConnection;

   public class SourceCode {0} {0}私人字符串来源;

   public SourceCode(URL pageURL) throws IOException { 
       this.source = getSource(pageURL); 
   } 
   
   public String getSource() { 
       return source; 
   } 
   
   private String getSource(URL url) throws IOException { 
       URLConnection spoof = url.openConnection(); 
       StringBuffer sb = new StringBuffer(); 
   
       spoof.setRequestProperty("User-Agent", 
         "Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0; H010818)"); 
       BufferedReader in = new BufferedReader(new InputStreamReader(
         spoof.getInputStream())); 
   
       String strLine = ""; 
       while ((strLine = in.readLine()) != null) { 
        sb.append(strLine); 
       } 
   
       return sb.toString(); 
   } 
   
   public static void main(String[] args) throws IOException { 
       SourceCode s = new SourceCode(new URL("https://www.google.co.in/")); 
       System.out.println(s.getSource()); 
   } 
   

   }