Java HttpURLConnection setInstanceFollowRedirects() 方法

 Java HttpURLConnection 类

Java HttpURLConnection setInstanceFollowRedirects() 方法设置此 HttpURLConnection 实例是否应自动遵循 HTTP 重定向（响应代码为 3xx 的请求）。

默认值来自 followRedirects ，默认为 true。

声明

以下是 java.net.URLConnection.setInstanceFollowRedirects() 方法的声明

public void setInstanceFollowRedirects(boolean followRedirects)

参数

followRedirects - 一个布尔值，指示是否遵循 HTTP 重定向。

返回值

此 HttpURLConnection 的值instanceFollowRedirects 字段。

异常

无

示例 1

以下示例显示 Java HttpURLConnection setInstanceFollowRedirects() 方法的用法使用 https 协议的有效 url。在此示例中，我们将创建 URL 类的实例。使用 url.openConnection() 方法，我们获取 HttpURLConnection 实例。使用 getInstanceFollowRedirects()，我们检查打印相同内容的 instanceFollowRedircts 标志值。现在使用 setInstanceFollowRedirects() 方法，我们更改 instanceFollowRedircts 标志的值并再次打印相同的值 -

package com.yxjc123;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUrlConnectionDemo {
   public static void main(String [] args) {
      try {
         URL url = new URL("https://www.yxjc123.com/index.htm?language=en#j2se");
         HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
         urlConnection.connect();  
         System.out.println("Connected.");  

         boolean result = urlConnection.getInstanceFollowRedirects();
         System.out.println("getInstanceFollowRedirects: " + result);  

         urlConnection.setInstanceFollowRedirects(false);
         result = urlConnection.getInstanceFollowRedirects();
         System.out.println("getInstanceFollowRedirects: " + result); 

         urlConnection.disconnect();
         System.out.println("Disconnected.");  
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}

让我们编译并运行上面的程序，这将产生以下结果 -

输出

Connected.
getInstanceFollowRedirects: true
getInstanceFollowRedirects: false
Disconnected.

示例 2

以下示例显示使用 Java HttpURLConnection setInstanceFollowRedirects() 方法获取具有 http 协议的有效 url。在此示例中，我们将创建 URL 类的实例。使用 url.openConnection() 方法，我们获取 HttpURLConnection 实例。使用 getInstanceFollowRedirects()，我们检查打印相同内容的 instanceFollowRedircts 标志值。现在使用 setInstanceFollowRedirects() 方法，我们更改 instanceFollowRedircts 标志的值并再次打印相同的值 -

package com.yxjc123;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUrlConnectionDemo {
   public static void main(String [] args) {
      try {
         URL url = new URL("http://www.yxjc123.com/index.htm?language=en#j2se");
         HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
         urlConnection.connect();  
         System.out.println("Connected.");  

         boolean result = urlConnection.getInstanceFollowRedirects();
         System.out.println("getInstanceFollowRedirects: " + result);  

         urlConnection.setInstanceFollowRedirects(false);
         result = urlConnection.getInstanceFollowRedirects();
         System.out.println("getInstanceFollowRedirects: " + result); 

         urlConnection.disconnect();
         System.out.println("Disconnected.");  
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}

让我们编译并运行上面的程序，这将产生以下结果 -

输出

Connected.
getInstanceFollowRedirects: true
getInstanceFollowRedirects: false
Disconnected.

示例 2

以下示例显示使用 Java HttpURLConnection setInstanceFollowRedirects() 方法获取具有 http 协议的有效 url。在此示例中，我们将创建 URL 类的实例。使用 url.openConnection() 方法，我们获取 HttpURLConnection 实例。使用 getInstanceFollowRedirects()，我们检查打印相同内容的 instanceFollowRedircts 标志值。现在使用 setInstanceFollowRedirects() 方法，我们更改 instanceFollowRedircts 标志的值并再次打印相同的值 -

package com.yxjc123;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUrlConnectionDemo {
   public static void main(String [] args) {
      try {
         URL url = new URL("http://www.baidu.com");
         HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
         urlConnection.connect();  
         System.out.println("Connected.");  

         boolean result = urlConnection.getInstanceFollowRedirects();
         System.out.println("getInstanceFollowRedirects: " + result);  

         urlConnection.setInstanceFollowRedirects(false);
         result = urlConnection.getInstanceFollowRedirects();
         System.out.println("getInstanceFollowRedirects: " + result); 

         urlConnection.disconnect();
         System.out.println("Disconnected.");  
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}

让我们编译并运行上面的程序，这将产生以下结果 -

输出

Connected.
getInstanceFollowRedirects: true
getInstanceFollowRedirects: false
Disconnected.