我有一些简单的代码,用于使用路标库学习 OAuth 身份验证。我正在尝试使用 java.util.prefs.Preferences
将请求 token 、 token secret 和 pin 保存为 Java 首选项。将数据放入首选项工作正常(我检查文件是否已创建并已存储信息)。但是,在将数据 put()
写入首选项文件后,我立即尝试检查节点是否存在,并且总是得到 false
。
我还尝试重新运行代码,并在尝试再次保存数据之前检查节点是否存在,但仍然是错误的。
我做错了什么?
这是代码:
package com.example;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.prefs.Preferences;
import oauth.signpost.OAuth;
import oauth.signpost.OAuthConsumer;
import oauth.signpost.OAuthProvider;
import oauth.signpost.basic.DefaultOAuthConsumer;
import oauth.signpost.basic.DefaultOAuthProvider;
public class ReadMain {
public static void main(String[] args) throws Exception {
OAuthConsumer consumer =
new DefaultOAuthConsumer(
"??",
"??");
OAuthProvider provider =
new DefaultOAuthProvider(
"https://www.readability.com/api/rest/v1/oauth/request_token/",
"https://www.readability.com/api/rest/v1/oauth/access_token/",
"https://www.readability.com/api/rest/v1/oauth/authorize/");
System.out.println("Fetching request token from Readability...");
Preferences prefs = Preferences.userNodeForPackage(ReadMain.class);
final String PREF_TokenSecret = "com/example/TS";
final String PREF_RequestToken = "com/example/RT";
final String PREF_ReadabilityPin = "com/example/RP";
boolean exists =
prefs.nodeExists( PREF_TokenSecret ) &&
prefs.nodeExists( PREF_RequestToken ) &&
prefs.nodeExists( PREF_ReadabilityPin );
if ( prefs.nodeExists( PREF_TokenSecret ) )
{
System.out.println("Token secret exists!");
}
if ( prefs.nodeExists( PREF_RequestToken ) )
{
System.out.println("Request token exists!");
}
if ( prefs.nodeExists( PREF_ReadabilityPin ) )
{
System.out.println("Readability pin exists!");
}
String pin;
if ( exists )
{
consumer.setTokenWithSecret(
prefs.get(PREF_RequestToken,""),
prefs.get(PREF_TokenSecret,"") );
pin = prefs.get(PREF_ReadabilityPin,"");
}
else
{
// we do not support callbacks, thus pass OOB
String authUrl = provider.retrieveRequestToken(consumer, OAuth.OUT_OF_BAND);
System.out.println( "Request token: " + consumer.getToken() );
System.out.println( "Token secret: " + consumer.getTokenSecret() );
prefs.put( PREF_RequestToken, consumer.getToken() );
prefs.put( PREF_TokenSecret, consumer.getTokenSecret() );
System.out.println( "Now visit:\n" + authUrl + "\n... and grant this app authorization" );
System.out.println( "Enter the PIN code and hit ENTER when you're done:" );
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
pin = br.readLine();
prefs.put(PREF_ReadabilityPin, pin);
if ( prefs.nodeExists( PREF_TokenSecret ) )
{
System.out.println("Token secret exists!");
}
if ( prefs.nodeExists( PREF_RequestToken ) )
{
System.out.println("Request token exists!");
}
if ( prefs.nodeExists( PREF_ReadabilityPin ) )
{
System.out.println("Readability pin exists!");
}
}
System.out.println("Fetching access token from Readability...");
provider.retrieveAccessToken(consumer, pin);
System.out.println("Access token: " + consumer.getToken());
System.out.println("Token secret: " + consumer.getTokenSecret());
URL url = new URL("https://www.readability.com/api/rest/v1/bookmarks?user=marcusps&archive=1");
HttpURLConnection request = (HttpURLConnection) url.openConnection();
consumer.sign(request);
System.out.println("Sending request to Readability...");
request.connect();
System.out.println("Response: " + request.getResponseCode() + " "
+ request.getResponseMessage());
}
}
最佳答案
put(..)
的相反操作是 get(..)
。所以:
boolean exists = prefs.get(key, null) != null;
如果在指定的键下没有找到任何内容,
get(..)
方法将返回第二个参数。nodeExists()
与首选项的层次结构有关,可以在使用 prefs.node(..)
创建节点时使用。但是你似乎需要一个扁平的结构,所以我认为你不需要层次结构。关于java.util.prefs.Preferences.put() 有效,但 Preferences.nodeExists() 总是返回 false,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/6011605/