小编Ahm*_*kol的帖子

我从http://weka.wikispaces.com/Programmatic+Use看了Weka的程序化例子.但是,我认为由于我的Weka jar版本(3.7.7),它在这一行上给出错误:

 Instance iExample = new Instance(4);

 Error: Cannot instantiate the type Instance

我应该对代码做什么样的改变？

我正在研究谷歌应用引擎,我陷入了困境.我正在尝试为我的实体创建一个密钥.这是代码:

Element child = (Element) itr.next();
                String name = "";
                if(child.getQualifiedName().equals("name")){
                    name += child.getText();
                }
                Key drugKey = KeyFactory.createKey("DrugTarget", name);

我100%确定child.getText()不返回null.我已经测试过了.我有另一段代码,创建Key完美无缺.两者看起来都很相似.

String drug = req.getParameter("drugname");
Key drugKey = KeyFactory.createKey("DrugTarget", drug);

我真的不明白它为什么会出错.第一段代码属于Java类,我在Java Servlet类中调用此类.第二个属于Java Servlet类.但我认为问题不同.能否请你帮忙？谢谢.

编辑部分:

if(child.getQualifiedName().equals("name")){
                    if(child.getText() != null){
                    name = child.getText();
                    }
                    else{
                        name = "asd";
                    }
                }

我把它放到我的代码中,仍然得到null错误.child.getText()不返回null,name不等于"asd".

忘了添加错误信息:

Uncaught exception from servlet
java.lang.IllegalArgumentException: name cannot be null or empty
at com.google.appengine.api.datastore.KeyFactory.createKey(KeyFactory.java:73)
at com.google.appengine.api.datastore.KeyFactory.createKey(KeyFactory.java:60)
at guestbook.saxParser2.getDrug(saxParser2.java:42)
at guestbook.SignGuestbookServlet.doPost(SignGuestbookServlet.java:77)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:102)
at …

我刚开始学习Ruby,经过一些基本的事情,我试图理解在ruby中对REST服务进行REST调用.我可以毫不费力地向foursquare API提出请求.另一方面,对Cisco CMX API的调用会出错.我的ruby版本是2.1.2.我在网上搜索了很多解决方案,但仍然遇到问题.这是我运行的shell命令.

工作一

$resclient
>> RestClient.get 'https://api.foursquare.com/v2/venues/search?ll=40.7,-74&oauth_token=0ZDO1JMJ0PW2QTCDK50OGZ21UENHZ0Y3KIDQZJLLURTQNRQ2&v=20150106'

这给出了错误

$restclient
>> RestClient.get 'https://learning:learning@64.103.26.61/api/contextaware/v1/maps/.json'

我的错误日志:

OpenSSL::SSL::SSLError: hostname "64.103.26.61" does not match the server certificate
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/2.1.0/openssl/ssl.rb:139:in `post_connection_check'
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/2.1.0/net/http.rb:922:in `connect'
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/2.1.0/net/http.rb:863:in `do_start'
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/2.1.0/net/http.rb:852:in `start'
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rest-client-1.7.2/lib/restclient/request.rb:413:in `transmit'
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rest-client-1.7.2/lib/restclient/request.rb:176:in `execute'
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rest-client-1.7.2/lib/restclient/request.rb:41:in `execute'
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rest-client-1.7.2/lib/restclient.rb:65:in `get'
from (irb):3
from /Users/apple/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/rest-client-1.7.2/bin/restclient:93:in `<top (required)>'
from /Users/apple/.rbenv/versions/2.1.2/bin/restclient:23:in `load'
from /Users/apple/.rbenv/versions/2.1.2/bin/restclient:23:in `<main>'

你能给点建议吗？谢谢

我试图显示实体列表,但我收到此错误:

javax.el.PropertyNotFoundException: Could not find property drug in class com.google.appengine.api.datastore.Entity

显示属性的方法是这样的:

 <c:forEach items="${drugtargets}" var="drugtarget">
<tr>
  <td>${drugtarget.drug}</td>
  <td>${drugtarget.target}</td>
</tr>

我检查了我的数据存储区和实体属性,但没有看到任何错误.我的属性是毒品和目标.你能告诉我应该怎么做吗？谢谢.

Key drugKey = KeyFactory.createKey("DrugTarget", drug);

Entity drugtarget = new Entity("DrugTarget",drugKey);
drugtarget.setProperty("drug", drug);
drugtarget.setProperty("target", target);

我正在从foursquare 获取场地列表，我需要获得的每个场地的名称、地址和城市。这里我的问题是，如果地址或城市为空，则会出现错误并显示“JSON 异常：地址无值”。我尝试了不同的方法来修复它，但无法解决问题。我希望你能帮助我。谢谢你。

JSONObject b = venues.getJSONObject(i);
JSONObject location = b.getJSONObject("location");

String name = "";
String address = "";
String city = "";

if ("".equals(b.get("name"))) {
    //  Toast.makeText(Activity2.this,"Name of Place: " +name+ " Location: "+country, Toast.LENGTH_SHORT).show();
    name = "No place ";
} else {
    name = b.getString("name");
}

if ("".equals(location.getString("address"))) {
    address = "No address";
} else {
    address = location.getString("address");
}

if ("".equals(location.getString("city"))) {
    city = "No city";
} else {
    city = location.getString("city");
}

name = "Name of …

我正在尝试学习如何使用 parse，此时我想知道如何在初始化时设置列的值（“安装”对象）。

这是我的 onCreate 方法。

    public void onCreate() {
    super.onCreate();

    Parse.initialize(this, "****", "****");
    ParseInstallation.getCurrentInstallation().saveInBackground();
    ParsePush.subscribeInBackground("", new SaveCallback() {
        @Override
        public void done(ParseException e) {
            if (e == null) {
                Log.d("com.parse.push", "successfully subscribed to the broadcast channel.");
            } else {
                Log.e("com.parse.push", "failed to subscribe for push", e);
            }
        }
    });

}

我添加了一个名为 MacID 的列。每当有人下载​​该应用程序时，我都想获取他们的 mac 地址并将其保存以解析对象。谢谢

我在我的程序开始时使用setInterval函数,但我的问题是我不想等到启动代码时.我希望它在应用此时间间隔后立即启动.这是我的代码:

    function initialize() {
setInterval(function(){myFunc()},5000);
}
google.setOnLoadCallback(initialize);