Question

我收到以下错误：

java.lang.IllegalStateException: Target host must not be null, or set in parameters. scheme=null, host=null, path=CONNECT_URL

以下是我的全局变量：

String CONNECT_URL = "http://api.openweathermap.org/data/2.5/weather?q=Mumbai";
    int LAST_INDEX; 
    String NAME; 
    String TYPE; 
    String GREETING_YEAR; 
    String GREETING_GENERAL; 
    String RADIO_TYPE;
    InputStream ins = null;
    String result = null;

以下是我的解析函数：

public void parse(){
        DefaultHttpClient http = new DefaultHttpClient(new BasicHttpParams()); 
        System.out.println("URL is: "+CONNECT_URL); 
        HttpPost httppost = new HttpPost("CONNECT_URL");
        httppost.setHeader("Content-type", "application/json");
        try{
            HttpResponse resp = http.execute(httppost); 
            HttpEntity entity = resp.getEntity();
            ins = entity.getContent(); 
            BufferedReader bufread = new BufferedReader(new InputStreamReader(ins, "UTF-8"), 8); 
            StringBuilder sb = new StringBuilder(); 
            String line = null; 

            while((line = bufread.readLine()) != null){

                sb.append(line +"\n"); 

            }
            result = sb.toString(); 
            System.out.println("Result: "+result); 

        }catch (Exception e){
            System.out.println("Error: "+e);
        }finally{
            try{
                if(ins != null){
                    ins.close();
                }
            }catch(Exception squish){
                System.out.println("Squish: "+squish); 
            }
        }



    }

我尝试用SO上的其他类似问题来修改它，但我的URL似乎没问题，一旦我从浏览器检查相同的URL，它会返回JSON，任何提示？

Answer 1

你有

HttpPost httppost = new HttpPost("CONNECT_URL");

并且查看您的代码应该像

HttpPost httppost = new HttpPost(CONNECT_URL);

Answer 2

您正在HttpPost对象中传递“CONNECT_URL”，这是错误的。使用

HttpPost httppost = new HttpPost(CONNECT_URL) //instead of HttpPost("CONNECT_URL")

Answer 3

HttpPost httppost = new HttpPost("CONNECT_URL");

应该是

HttpPost httppost = new HttpPost(CONNECT_URL);

作为旁注，Java约定规定变量是驼峰式的（connectUrl），常量是大写的（CONNECT_URL）。

Answer 4

我认为问题来自这一行：

HttpPost httppost = new HttpPost("CONNECT_URL");

您传递的是字符串"CONNECT_URL"，而不是传递变量CONNECT_URL：）

Http Url连接错误

4 个答案: