java通过url读取文件内容示例

using System;
 using System.Collections;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Web;
 using System.Web.SessionState;
 using System.Web.UI;
 using System.Web.UI.WebControls;
 using System.Web.UI.HtmlControls;
 using System.IO;
 using System.Net;
 using System.Text;
 using System.Text.RegularExpressions;
 namespace eMeng.Exam
 {
 ///  <summary>
 /// GetPageHtml 的摘要说明。
 ///  </summary>
 public class GetPageHtml : System.Web.UI.Page
 {
 protected System.Web.UI.WebControls.Button WebClientButton;
 protected System.Web.UI.WebControls.Button WebRequestButton;
 protected System.Web.UI.WebControls.TextBox ContentHtml;
 protected System.Web.UI.WebControls.TextBox UrlText;
 protected System.Web.UI.WebControls.Button GetText;
 private string PageUrl = "";

 private void Page_Load(object sender, System.EventArgs e)
  {}

 #region Web Form Designer generated code
 override protected void OnInit(EventArgs e)
  {
  InitializeComponent();
  base.OnInit(e);
 }

 ///  <summary>
 /// 设计器支持所需的方法 - 不要使用代码编辑器修改
 /// 此方法的内容。
 ///  </summary>
 private void InitializeComponent()
 {    
     this.WebClientButton.Click += new System.EventHandler(this.WebClientButton_Click);
     this.WebRequestButton.Click += new System.EventHandler(this.WebRequestButton_Click);
     this.GetText.Click += new System.EventHandler(this.GetText_Click);
     this.Load += new System.EventHandler(this.Page_Load);

 }
 #endregion

 private void WebClientButton_Click(object sender, System.EventArgs e)
 {
  PageUrl = UrlText.Text;
  WebClient wc = new WebClient();
  wc.Credentials = CredentialCache.DefaultCredentials;

  ///方法一：
  Byte[] pageData = wc.DownloadData(PageUrl);
  ContentHtml.Text = Encoding.Default.GetString(pageData);    

 
  /// 方法二：
  /// ***************代码开始**********
  /// Stream resStream = wc.OpenRead(PageUrl);
  /// StreamReader sr = new StreamReader(resStream,System.Text.Encoding.Default);
  /// ContentHtml.Text = sr.ReadToEnd();
  /// resStream.Close();
  /// **************代码结束********
  /// 
 wc.Dispose();  
 }

 private void WebRequestButton_Click(object sender, System.EventArgs e)
 {
  PageUrl = UrlText.Text;
  WebRequest  request = WebRequest.Create(PageUrl);
  WebResponse response = request.GetResponse();
  Stream resStream = response.GetResponseStream();    
  StreamReader sr = new StreamReader(resStream, System.Text.Encoding.Default);
  ContentHtml.Text = sr.ReadToEnd();
  resStream.Close(); 
  sr.Close();
 }

 private void GetText_Click(object sender, System.EventArgs e)
  {
     PageUrl = UrlText.Text;
     WebRequest  request = WebRequest.Create(PageUrl);
     WebResponse response = request.GetResponse();
     Stream resStream = response.GetResponseStream();    
     StreamReader sr = new StreamReader(resStream, System.Text.Encoding.Default);
     ContentHtml.Text = sr.ReadToEnd();
     resStream.Close(); 
     sr.Close();
     ContentHtml.Text = Regex.Replace(ContentHtml.Text," <[^>]*>", "");
     //替换空格
     ContentHtml.Text = Regex.Replace(ContentHtml.Text,"\\s+", " ");
  }
 }